id
stringlengths
14
28
title
stringclasses
18 values
text
stringlengths
2
999
contents
stringlengths
19
1.02k
Anatomy_Gray_400
Anatomy_Gray
The naming of the three cusps, the anterior, septal, and posterior cusps, is based on their relative position in the right ventricle. The free margins of the cusps are attached to the chordae tendineae, which arise from the tips of the papillary muscles. During filling of the right ventricle, the tricuspid valve is open, and the three cusps project into the right ventricle. Without the presence of a compensating mechanism, when the ventricular musculature contracts, the valve cusps would be forced upward with the flow of blood and blood would move back into the right atrium. However, contraction of the papillary muscles attached to the cusps by chordae tendineae prevents the cusps from being everted into the right atrium. Simply put, the papillary muscles and associated chordae tendineae keep the valves closed during the dramatic changes in ventricular size that occur during contraction.
Anatomy_Gray. The naming of the three cusps, the anterior, septal, and posterior cusps, is based on their relative position in the right ventricle. The free margins of the cusps are attached to the chordae tendineae, which arise from the tips of the papillary muscles. During filling of the right ventricle, the tricuspid valve is open, and the three cusps project into the right ventricle. Without the presence of a compensating mechanism, when the ventricular musculature contracts, the valve cusps would be forced upward with the flow of blood and blood would move back into the right atrium. However, contraction of the papillary muscles attached to the cusps by chordae tendineae prevents the cusps from being everted into the right atrium. Simply put, the papillary muscles and associated chordae tendineae keep the valves closed during the dramatic changes in ventricular size that occur during contraction.
Anatomy_Gray_401
Anatomy_Gray
Simply put, the papillary muscles and associated chordae tendineae keep the valves closed during the dramatic changes in ventricular size that occur during contraction. In addition, chordae tendineae from two papillary muscles attach to each cusp. This helps prevent separation of the cusps during ventricular contraction. Proper closing of the tricuspid valve causes blood to exit the right ventricle and move into the pulmonary trunk. Necrosis of a papillary muscle following a myocardial infarction (heart attack) may result in prolapse of the related valve.
Anatomy_Gray. Simply put, the papillary muscles and associated chordae tendineae keep the valves closed during the dramatic changes in ventricular size that occur during contraction. In addition, chordae tendineae from two papillary muscles attach to each cusp. This helps prevent separation of the cusps during ventricular contraction. Proper closing of the tricuspid valve causes blood to exit the right ventricle and move into the pulmonary trunk. Necrosis of a papillary muscle following a myocardial infarction (heart attack) may result in prolapse of the related valve.
Anatomy_Gray_402
Anatomy_Gray
Necrosis of a papillary muscle following a myocardial infarction (heart attack) may result in prolapse of the related valve. At the apex of the infundibulum, the outflow tract of the right ventricle, the opening into the pulmonary trunk is closed by the pulmonary valve (Fig. 3.71), which consists of three semilunar cusps with free edges projecting upward into the lumen of the pulmonary trunk. The free superior edge of each cusp has a middle, thickened portion, the nodule of the semilunar cusp, and a thin lateral portion, the lunula of the semilunar cusp (Fig. 3.72).
Anatomy_Gray. Necrosis of a papillary muscle following a myocardial infarction (heart attack) may result in prolapse of the related valve. At the apex of the infundibulum, the outflow tract of the right ventricle, the opening into the pulmonary trunk is closed by the pulmonary valve (Fig. 3.71), which consists of three semilunar cusps with free edges projecting upward into the lumen of the pulmonary trunk. The free superior edge of each cusp has a middle, thickened portion, the nodule of the semilunar cusp, and a thin lateral portion, the lunula of the semilunar cusp (Fig. 3.72).
Anatomy_Gray_403
Anatomy_Gray
The cusps are named the left, right, and anterior semilunar cusps, relative to their fetal position before rotation of the outflow tracts from the ventricles is complete. Each cusp forms a pocket-like sinus (Fig. 3.72)—a dilation in the wall of the initial portion of the pulmonary trunk. After ventricular contraction, the recoil of blood fills these pulmonary sinuses and forces the cusps closed. This prevents blood in the pulmonary trunk from refilling the right ventricle. The left atrium forms most of the base or posterior surface of the heart. As with the right atrium, the left atrium is derived embryologically from two structures. The posterior half, or inflow portion, receives the four pulmonary veins (Fig. 3.73). It has smooth walls and derives from the proximal parts of the pulmonary veins that are incorporated into the left atrium during development.
Anatomy_Gray. The cusps are named the left, right, and anterior semilunar cusps, relative to their fetal position before rotation of the outflow tracts from the ventricles is complete. Each cusp forms a pocket-like sinus (Fig. 3.72)—a dilation in the wall of the initial portion of the pulmonary trunk. After ventricular contraction, the recoil of blood fills these pulmonary sinuses and forces the cusps closed. This prevents blood in the pulmonary trunk from refilling the right ventricle. The left atrium forms most of the base or posterior surface of the heart. As with the right atrium, the left atrium is derived embryologically from two structures. The posterior half, or inflow portion, receives the four pulmonary veins (Fig. 3.73). It has smooth walls and derives from the proximal parts of the pulmonary veins that are incorporated into the left atrium during development.
Anatomy_Gray_404
Anatomy_Gray
The anterior half is continuous with the left auricle. It contains musculi pectinati and derives from the embryonic primitive atrium. Unlike the crista terminalis in the right atrium, no distinct structure separates the two components of the left atrium. The interatrial septum is part of the anterior wall of the left atrium. The thin area or depression in the septum is the valve of the foramen ovale and is opposite the floor of the fossa ovalis in the right atrium. During development, the valve of the foramen ovale prevents blood from passing from the left atrium to the right atrium. This valve may not be completely fused in some adults, leaving a “probe patent” passage between the right atrium and the left atrium. The left ventricle lies anterior to the left atrium. It contributes to the anterior, diaphragmatic, and left pulmonary surfaces of the heart, and forms the apex.
Anatomy_Gray. The anterior half is continuous with the left auricle. It contains musculi pectinati and derives from the embryonic primitive atrium. Unlike the crista terminalis in the right atrium, no distinct structure separates the two components of the left atrium. The interatrial septum is part of the anterior wall of the left atrium. The thin area or depression in the septum is the valve of the foramen ovale and is opposite the floor of the fossa ovalis in the right atrium. During development, the valve of the foramen ovale prevents blood from passing from the left atrium to the right atrium. This valve may not be completely fused in some adults, leaving a “probe patent” passage between the right atrium and the left atrium. The left ventricle lies anterior to the left atrium. It contributes to the anterior, diaphragmatic, and left pulmonary surfaces of the heart, and forms the apex.
Anatomy_Gray_405
Anatomy_Gray
The left ventricle lies anterior to the left atrium. It contributes to the anterior, diaphragmatic, and left pulmonary surfaces of the heart, and forms the apex. Blood enters the ventricle through the left atrioventricular orifice and flows in a forward direction to the apex. The chamber itself is conical, is longer than the right ventricle, and has the thickest layer of myocardium. The outflow tract (the aortic vestibule) is posterior to the infundibulum of the right ventricle, has smooth walls, and is derived from the embryonic bulbus cordis. The trabeculae carneae in the left ventricle are fine and delicate in contrast to those in the right ventricle. The general appearance of the trabeculae with muscular ridges and bridges is similar to that of the right ventricle (Fig. 3.74).
Anatomy_Gray. The left ventricle lies anterior to the left atrium. It contributes to the anterior, diaphragmatic, and left pulmonary surfaces of the heart, and forms the apex. Blood enters the ventricle through the left atrioventricular orifice and flows in a forward direction to the apex. The chamber itself is conical, is longer than the right ventricle, and has the thickest layer of myocardium. The outflow tract (the aortic vestibule) is posterior to the infundibulum of the right ventricle, has smooth walls, and is derived from the embryonic bulbus cordis. The trabeculae carneae in the left ventricle are fine and delicate in contrast to those in the right ventricle. The general appearance of the trabeculae with muscular ridges and bridges is similar to that of the right ventricle (Fig. 3.74).
Anatomy_Gray_406
Anatomy_Gray
The general appearance of the trabeculae with muscular ridges and bridges is similar to that of the right ventricle (Fig. 3.74). Papillary muscles, together with chordae tendineae, are also observed and their structure is as described above for the right ventricle. Two papillary muscles, the anterior and posterior papillary muscles, are usually found in the left ventricle and are larger than those of the right ventricle. In the anatomical position, the left ventricle is somewhat posterior to the right ventricle. The interventricular septum therefore forms the anterior wall and some of the wall on the right side of the left ventricle. The septum is described as having two parts: a muscular part, and a membranous part.
Anatomy_Gray. The general appearance of the trabeculae with muscular ridges and bridges is similar to that of the right ventricle (Fig. 3.74). Papillary muscles, together with chordae tendineae, are also observed and their structure is as described above for the right ventricle. Two papillary muscles, the anterior and posterior papillary muscles, are usually found in the left ventricle and are larger than those of the right ventricle. In the anatomical position, the left ventricle is somewhat posterior to the right ventricle. The interventricular septum therefore forms the anterior wall and some of the wall on the right side of the left ventricle. The septum is described as having two parts: a muscular part, and a membranous part.
Anatomy_Gray_407
Anatomy_Gray
The muscular part is thick and forms the major part of the septum, whereas the membranous part is the thin, upper part of the septum. A third part of the septum may be considered an atrioventricular part because of its position above the septal cusp of the tricuspid valve. This superior location places this part of the septum between the left ventricle and right atrium. The left atrioventricular orifice opens into the posterior right side of the superior part of the left ventricle. It is closed during ventricular contraction by the mitral valve (left atrioventricular valve), which is also referred to as the bicuspid valve because it has two cusps, the anterior and posterior cusps (Fig. 3.74). The bases of the cusps are secured to a fibrous ring surrounding the opening, and the cusps are continuous with each other at the commissures. The coordinated action of the papillary muscles and chordae tendineae is as described for the right ventricle.
Anatomy_Gray. The muscular part is thick and forms the major part of the septum, whereas the membranous part is the thin, upper part of the septum. A third part of the septum may be considered an atrioventricular part because of its position above the septal cusp of the tricuspid valve. This superior location places this part of the septum between the left ventricle and right atrium. The left atrioventricular orifice opens into the posterior right side of the superior part of the left ventricle. It is closed during ventricular contraction by the mitral valve (left atrioventricular valve), which is also referred to as the bicuspid valve because it has two cusps, the anterior and posterior cusps (Fig. 3.74). The bases of the cusps are secured to a fibrous ring surrounding the opening, and the cusps are continuous with each other at the commissures. The coordinated action of the papillary muscles and chordae tendineae is as described for the right ventricle.
Anatomy_Gray_408
Anatomy_Gray
The aortic vestibule, or outflow tract of the left ventricle, is continuous superiorly with the ascending aorta. The opening from the left ventricle into the aorta is closed by the aortic valve. This valve is similar in structure to the pulmonary valve. It consists of three semilunar cusps with the free edge of each projecting upward into the lumen of the ascending aorta (Fig. 3.75). Between the semilunar cusps and the wall of the ascending aorta are pocket-like sinuses—the right, left, and posterior aortic sinuses. The right and left coronary arteries originate from the right and left aortic sinuses. Because of this, the posterior aortic sinus and cusp are sometimes referred to as the noncoronary sinus and cusp.
Anatomy_Gray. The aortic vestibule, or outflow tract of the left ventricle, is continuous superiorly with the ascending aorta. The opening from the left ventricle into the aorta is closed by the aortic valve. This valve is similar in structure to the pulmonary valve. It consists of three semilunar cusps with the free edge of each projecting upward into the lumen of the ascending aorta (Fig. 3.75). Between the semilunar cusps and the wall of the ascending aorta are pocket-like sinuses—the right, left, and posterior aortic sinuses. The right and left coronary arteries originate from the right and left aortic sinuses. Because of this, the posterior aortic sinus and cusp are sometimes referred to as the noncoronary sinus and cusp.
Anatomy_Gray_409
Anatomy_Gray
The functioning of the aortic valve is similar to that of the pulmonary valve with one important additional process: as blood recoils after ventricular contraction and fills the aortic sinuses, it is automatically forced into the coronary arteries because these vessels originate from the right and left aortic sinuses. The cardiac skeleton is a collection of dense, fibrous connective tissue in the form of four rings with interconnecting areas in a plane between the atria and the ventricles. The four rings of the cardiac skeleton surround the two atrioventricular orifices, the aortic orifice and opening of the pulmonary trunks. They are the anulus fibrosus. The interconnecting areas include: the right fibrous trigone, which is a thickened area of connective tissue between the aortic ring and right atrioventricular ring; and the left fibrous trigone, which is a thickened area of connective tissue between the aortic ring and the left atrioventricular ring (Fig. 3.76).
Anatomy_Gray. The functioning of the aortic valve is similar to that of the pulmonary valve with one important additional process: as blood recoils after ventricular contraction and fills the aortic sinuses, it is automatically forced into the coronary arteries because these vessels originate from the right and left aortic sinuses. The cardiac skeleton is a collection of dense, fibrous connective tissue in the form of four rings with interconnecting areas in a plane between the atria and the ventricles. The four rings of the cardiac skeleton surround the two atrioventricular orifices, the aortic orifice and opening of the pulmonary trunks. They are the anulus fibrosus. The interconnecting areas include: the right fibrous trigone, which is a thickened area of connective tissue between the aortic ring and right atrioventricular ring; and the left fibrous trigone, which is a thickened area of connective tissue between the aortic ring and the left atrioventricular ring (Fig. 3.76).
Anatomy_Gray_410
Anatomy_Gray
The cardiac skeleton helps maintain the integrity of the openings it surrounds and provides points of attachment for the cusps. It also separates the atrial musculature from the ventricular musculature. The atrial myocardium originates from the upper border of the rings, whereas the ventricular myocardium originates from the lower border of the rings. The cardiac skeleton also serves as a dense connective tissue partition that electrically isolates the atria from the ventricles. The atrioventricular bundle, which passes through the anulus, is the single connection between these two groups of myocardium. Two coronary arteries arise from the aortic sinuses in the initial portion of the ascending aorta and supply the muscle and other tissues of the heart. They circle the heart in the coronary sulcus, with marginal and interventricular branches, in the interventricular sulci, converging toward the apex of the heart (Fig. 3.77).
Anatomy_Gray. The cardiac skeleton helps maintain the integrity of the openings it surrounds and provides points of attachment for the cusps. It also separates the atrial musculature from the ventricular musculature. The atrial myocardium originates from the upper border of the rings, whereas the ventricular myocardium originates from the lower border of the rings. The cardiac skeleton also serves as a dense connective tissue partition that electrically isolates the atria from the ventricles. The atrioventricular bundle, which passes through the anulus, is the single connection between these two groups of myocardium. Two coronary arteries arise from the aortic sinuses in the initial portion of the ascending aorta and supply the muscle and other tissues of the heart. They circle the heart in the coronary sulcus, with marginal and interventricular branches, in the interventricular sulci, converging toward the apex of the heart (Fig. 3.77).
Anatomy_Gray_411
Anatomy_Gray
The returning venous blood passes through cardiac veins, most of which empty into the coronary sinus. This large venous structure is located in the coronary sulcus on the posterior surface of the heart between the left atrium and left ventricle. The coronary sinus empties into the right atrium between the opening of the inferior vena cava and the right atrioventricular orifice. Right coronary artery. The right coronary artery originates from the right aortic sinus of the ascending aorta. It passes anteriorly and then descends vertically in the coronary sulcus, between the right atrium and right ventricle (Fig. 3.78A). On reaching the inferior margin of the heart, it turns posteriorly and continues in the sulcus onto the diaphragmatic surface and base of the heart. During this course, several branches arise from the main stem of the vessel:
Anatomy_Gray. The returning venous blood passes through cardiac veins, most of which empty into the coronary sinus. This large venous structure is located in the coronary sulcus on the posterior surface of the heart between the left atrium and left ventricle. The coronary sinus empties into the right atrium between the opening of the inferior vena cava and the right atrioventricular orifice. Right coronary artery. The right coronary artery originates from the right aortic sinus of the ascending aorta. It passes anteriorly and then descends vertically in the coronary sulcus, between the right atrium and right ventricle (Fig. 3.78A). On reaching the inferior margin of the heart, it turns posteriorly and continues in the sulcus onto the diaphragmatic surface and base of the heart. During this course, several branches arise from the main stem of the vessel:
Anatomy_Gray_412
Anatomy_Gray
An early atrial branch passes in the groove between the right auricle and ascending aorta, and gives off the sinu-atrial nodal branch (Fig. 3.78A), which passes posteriorly around the superior vena cava to supply the sinu-atrial node. A right marginal branch is given off as the right coronary artery approaches the inferior (acute) margin of the heart (Fig. 3.78A,B) and continues along this border toward the apex of the heart. As the right coronary artery continues on the base/ diaphragmatic surface of the heart, it supplies a small branch to the atrioventricular node before giving off its final major branch, the posterior interventricular branch (Fig. 3.78A), which lies in the posterior interventricular sulcus.
Anatomy_Gray. An early atrial branch passes in the groove between the right auricle and ascending aorta, and gives off the sinu-atrial nodal branch (Fig. 3.78A), which passes posteriorly around the superior vena cava to supply the sinu-atrial node. A right marginal branch is given off as the right coronary artery approaches the inferior (acute) margin of the heart (Fig. 3.78A,B) and continues along this border toward the apex of the heart. As the right coronary artery continues on the base/ diaphragmatic surface of the heart, it supplies a small branch to the atrioventricular node before giving off its final major branch, the posterior interventricular branch (Fig. 3.78A), which lies in the posterior interventricular sulcus.
Anatomy_Gray_413
Anatomy_Gray
The right coronary artery supplies the right atrium and right ventricle, the sinu-atrial and atrioventricular nodes, the interatrial septum, a portion of the left atrium, the posteroinferior one third of the interventricular septum, and a portion of the posterior part of the left ventricle. Left coronary artery. The left coronary artery originates from the left aortic sinus of the ascending aorta. It passes between the pulmonary trunk and the left auricle before entering the coronary sulcus. Emerging from behind the pulmonary trunk, the artery divides into its two terminal branches, the anterior interventricular and the circumflex (Fig. 3.78A).
Anatomy_Gray. The right coronary artery supplies the right atrium and right ventricle, the sinu-atrial and atrioventricular nodes, the interatrial septum, a portion of the left atrium, the posteroinferior one third of the interventricular septum, and a portion of the posterior part of the left ventricle. Left coronary artery. The left coronary artery originates from the left aortic sinus of the ascending aorta. It passes between the pulmonary trunk and the left auricle before entering the coronary sulcus. Emerging from behind the pulmonary trunk, the artery divides into its two terminal branches, the anterior interventricular and the circumflex (Fig. 3.78A).
Anatomy_Gray_414
Anatomy_Gray
The anterior interventricular branch (left anterior descending artery—LAD) (Fig. 3.78A,C) continues around the left side of the pulmonary trunk and descends obliquely toward the apex of the heart in the anterior interventricular sulcus (Fig. 3.78A,C). During its course, one or two large diagonal branches may arise and descend diagonally across the anterior surface of the left ventricle. The circumflex branch (Fig. 3.78A,C) courses toward the left, in the coronary sulcus and onto the base/diaphragmatic surface of the heart, and usually ends before reaching the posterior interventricular sulcus. A large branch, the left marginal artery (Fig. 3.78A,C), usually arises from it and continues across the rounded obtuse margin of the heart. The distribution pattern of the left coronary artery enables it to supply most of the left atrium and left ventricle, and most of the interventricular septum, including the atrioventricular bundle and its branches.
Anatomy_Gray. The anterior interventricular branch (left anterior descending artery—LAD) (Fig. 3.78A,C) continues around the left side of the pulmonary trunk and descends obliquely toward the apex of the heart in the anterior interventricular sulcus (Fig. 3.78A,C). During its course, one or two large diagonal branches may arise and descend diagonally across the anterior surface of the left ventricle. The circumflex branch (Fig. 3.78A,C) courses toward the left, in the coronary sulcus and onto the base/diaphragmatic surface of the heart, and usually ends before reaching the posterior interventricular sulcus. A large branch, the left marginal artery (Fig. 3.78A,C), usually arises from it and continues across the rounded obtuse margin of the heart. The distribution pattern of the left coronary artery enables it to supply most of the left atrium and left ventricle, and most of the interventricular septum, including the atrioventricular bundle and its branches.
Anatomy_Gray_415
Anatomy_Gray
Variations in the distribution patterns of coronary arteries. Several major variations in the basic distribution patterns of the coronary arteries occur. The distribution pattern described above for both right and left coronary arteries is the most common and consists of a right dominant coronary artery. This means that the posterior interventricular branch arises from the right coronary artery. The right coronary artery therefore supplies a large portion of the posterior wall of the left ventricle and the circumflex branch of the left coronary artery is relatively small. In contrast, in hearts with a left dominant coronary artery, the posterior interventricular branch arises from an enlarged circumflex branch and supplies most of the posterior wall of the left ventricle (Fig. 3.79).
Anatomy_Gray. Variations in the distribution patterns of coronary arteries. Several major variations in the basic distribution patterns of the coronary arteries occur. The distribution pattern described above for both right and left coronary arteries is the most common and consists of a right dominant coronary artery. This means that the posterior interventricular branch arises from the right coronary artery. The right coronary artery therefore supplies a large portion of the posterior wall of the left ventricle and the circumflex branch of the left coronary artery is relatively small. In contrast, in hearts with a left dominant coronary artery, the posterior interventricular branch arises from an enlarged circumflex branch and supplies most of the posterior wall of the left ventricle (Fig. 3.79).
Anatomy_Gray_416
Anatomy_Gray
Another point of variation relates to the arterial supply to the sinu-atrial and atrioventricular nodes. In most cases, these two structures are supplied by the right coronary artery. However, vessels from the circumflex branch of the left coronary artery occasionally supply these structures. The coronary sinus receives four major tributaries: the great, middle, small, and posterior cardiac veins.
Anatomy_Gray. Another point of variation relates to the arterial supply to the sinu-atrial and atrioventricular nodes. In most cases, these two structures are supplied by the right coronary artery. However, vessels from the circumflex branch of the left coronary artery occasionally supply these structures. The coronary sinus receives four major tributaries: the great, middle, small, and posterior cardiac veins.
Anatomy_Gray_417
Anatomy_Gray
The coronary sinus receives four major tributaries: the great, middle, small, and posterior cardiac veins. Great cardiac vein. The great cardiac vein begins at the apex of the heart (Fig. 3.82A). It ascends in the anterior interventricular sulcus, where it is related to the anterior interventricular artery and is often termed the anterior interventricular vein. Reaching the coronary sulcus, the great cardiac vein turns to the left and continues onto the base/diaphragmatic surface of the heart. At this point, it is associated with the circumflex branch of the left coronary artery. Continuing along its path in the coronary sulcus, the great cardiac vein gradually enlarges to form the coronary sinus, which enters the right atrium (Fig. 3.82B).
Anatomy_Gray. The coronary sinus receives four major tributaries: the great, middle, small, and posterior cardiac veins. Great cardiac vein. The great cardiac vein begins at the apex of the heart (Fig. 3.82A). It ascends in the anterior interventricular sulcus, where it is related to the anterior interventricular artery and is often termed the anterior interventricular vein. Reaching the coronary sulcus, the great cardiac vein turns to the left and continues onto the base/diaphragmatic surface of the heart. At this point, it is associated with the circumflex branch of the left coronary artery. Continuing along its path in the coronary sulcus, the great cardiac vein gradually enlarges to form the coronary sinus, which enters the right atrium (Fig. 3.82B).
Anatomy_Gray_418
Anatomy_Gray
Middle cardiac vein. The middle cardiac vein (posterior interventricular vein) begins near the apex of the heart and ascends in the posterior interventricular sulcus toward the coronary sinus (Fig. 3.82B). It is associated with the posterior interventricular branch of the right or left coronary artery throughout its course. Small cardiac vein. The small cardiac vein begins in the lower anterior section of the coronary sulcus between the right atrium and right ventricle (Fig. 3.82A). It continues in this groove onto the base/diaphragmatic surface of the heart where it enters the coronary sinus at its atrial end. It is a companion of the right coronary artery throughout its course and may receive the right marginal vein (Fig. 3.82A). This small vein accompanies the marginal branch of the right coronary artery along the acute margin of the heart. If the right marginal vein does not join the small cardiac vein, it enters the right atrium directly.
Anatomy_Gray. Middle cardiac vein. The middle cardiac vein (posterior interventricular vein) begins near the apex of the heart and ascends in the posterior interventricular sulcus toward the coronary sinus (Fig. 3.82B). It is associated with the posterior interventricular branch of the right or left coronary artery throughout its course. Small cardiac vein. The small cardiac vein begins in the lower anterior section of the coronary sulcus between the right atrium and right ventricle (Fig. 3.82A). It continues in this groove onto the base/diaphragmatic surface of the heart where it enters the coronary sinus at its atrial end. It is a companion of the right coronary artery throughout its course and may receive the right marginal vein (Fig. 3.82A). This small vein accompanies the marginal branch of the right coronary artery along the acute margin of the heart. If the right marginal vein does not join the small cardiac vein, it enters the right atrium directly.
Anatomy_Gray_419
Anatomy_Gray
Posterior cardiac vein. The posterior cardiac vein lies on the posterior surface of the left ventricle just to the left of the middle cardiac vein (Fig. 3.82B). It either enters the coronary sinus directly or joins the great cardiac vein. Other cardiac veins. Two additional groups of cardiac veins are also involved in the venous drainage of the heart. The anterior veins of the right ventricle (anterior cardiac veins) are small veins that arise on the anterior surface of the right ventricle (Fig. 3.82A). They cross the coronary sulcus and enter the anterior wall of the right atrium. They drain the anterior portion of the right ventricle. The right marginal vein may be part of this group if it does not enter the small cardiac vein.
Anatomy_Gray. Posterior cardiac vein. The posterior cardiac vein lies on the posterior surface of the left ventricle just to the left of the middle cardiac vein (Fig. 3.82B). It either enters the coronary sinus directly or joins the great cardiac vein. Other cardiac veins. Two additional groups of cardiac veins are also involved in the venous drainage of the heart. The anterior veins of the right ventricle (anterior cardiac veins) are small veins that arise on the anterior surface of the right ventricle (Fig. 3.82A). They cross the coronary sulcus and enter the anterior wall of the right atrium. They drain the anterior portion of the right ventricle. The right marginal vein may be part of this group if it does not enter the small cardiac vein.
Anatomy_Gray_420
Anatomy_Gray
A group of smallest cardiac veins (venae cordis minimae or veins of Thebesius) have also been described. Draining directly into the cardiac chambers, they are numerous in the right atrium and right ventricle, are occasionally associated with the left atrium, and are rarely associated with the left ventricle. The lymphatic vessels of the heart follow the coronary arteries and drain mainly into: brachiocephalic nodes, anterior to the brachiocephalic veins; and tracheobronchial nodes, at the inferior end of the trachea. The musculature of the atria and ventricles is capable of contracting spontaneously. The cardiac conduction system initiates and coordinates contraction. The conduction system consists of nodes and networks of specialized cardiac muscle cells organized into four basic components: the sinu-atrial node, the atrioventricular node, the atrioventricular bundle with its right and left bundle branches, and the subendocardial plexus of conduction cells (the Purkinje fibers).
Anatomy_Gray. A group of smallest cardiac veins (venae cordis minimae or veins of Thebesius) have also been described. Draining directly into the cardiac chambers, they are numerous in the right atrium and right ventricle, are occasionally associated with the left atrium, and are rarely associated with the left ventricle. The lymphatic vessels of the heart follow the coronary arteries and drain mainly into: brachiocephalic nodes, anterior to the brachiocephalic veins; and tracheobronchial nodes, at the inferior end of the trachea. The musculature of the atria and ventricles is capable of contracting spontaneously. The cardiac conduction system initiates and coordinates contraction. The conduction system consists of nodes and networks of specialized cardiac muscle cells organized into four basic components: the sinu-atrial node, the atrioventricular node, the atrioventricular bundle with its right and left bundle branches, and the subendocardial plexus of conduction cells (the Purkinje fibers).
Anatomy_Gray_421
Anatomy_Gray
The unique distribution pattern of the cardiac conduction system establishes an important unidirectional pathway of excitation/contraction. Throughout its course, large branches of the conduction system are insulated from the surrounding myocardium by connective tissue. This tends to decrease inappropriate stimulation and contraction of cardiac muscle fibers. The number of functional contacts between the conduction pathway and cardiac musculature greatly increases in the subendocardial network. Thus, a unidirectional wave of excitation and contraction is established, which moves from the papillary muscles and apex of the ventricles to the arterial outflow tracts. Impulses begin at the sinu-atrial node, the cardiac pacemaker. This collection of cells is located at the superior end of the crista terminalis at the junction of the superior vena cava and the right atrium (Fig. 3.83A).
Anatomy_Gray. The unique distribution pattern of the cardiac conduction system establishes an important unidirectional pathway of excitation/contraction. Throughout its course, large branches of the conduction system are insulated from the surrounding myocardium by connective tissue. This tends to decrease inappropriate stimulation and contraction of cardiac muscle fibers. The number of functional contacts between the conduction pathway and cardiac musculature greatly increases in the subendocardial network. Thus, a unidirectional wave of excitation and contraction is established, which moves from the papillary muscles and apex of the ventricles to the arterial outflow tracts. Impulses begin at the sinu-atrial node, the cardiac pacemaker. This collection of cells is located at the superior end of the crista terminalis at the junction of the superior vena cava and the right atrium (Fig. 3.83A).
Anatomy_Gray_422
Anatomy_Gray
This is also the junction between the parts of the right atrium derived from the embryonic sinus venosus and the atrium proper. The excitation signals generated by the sinu-atrial node spread across the atria, causing the muscle to contract. Concurrently, the wave of excitation in the atria stimulates the atrioventricular node, which is located near the opening of the coronary sinus, close to the attachment of the septal cusp of the tricuspid valve, and within the atrioventricular septum (Fig. 3.83A). The atrioventricular node is a collection of specialized cells that forms the beginning of an elaborate system of conducting tissue, the atrioventricular bundle, which extends the excitatory impulse to all ventricular musculature. The atrioventricular bundle is a direct continuation of the atrioventricular node (Fig. 3.83A). It follows along the lower border of the membranous part of the interventricular septum before splitting into right and left bundles.
Anatomy_Gray. This is also the junction between the parts of the right atrium derived from the embryonic sinus venosus and the atrium proper. The excitation signals generated by the sinu-atrial node spread across the atria, causing the muscle to contract. Concurrently, the wave of excitation in the atria stimulates the atrioventricular node, which is located near the opening of the coronary sinus, close to the attachment of the septal cusp of the tricuspid valve, and within the atrioventricular septum (Fig. 3.83A). The atrioventricular node is a collection of specialized cells that forms the beginning of an elaborate system of conducting tissue, the atrioventricular bundle, which extends the excitatory impulse to all ventricular musculature. The atrioventricular bundle is a direct continuation of the atrioventricular node (Fig. 3.83A). It follows along the lower border of the membranous part of the interventricular septum before splitting into right and left bundles.
Anatomy_Gray_423
Anatomy_Gray
The right bundle branch continues on the right side of the interventricular septum toward the apex of the right ventricle. From the septum it enters the septomarginal trabecula to reach the base of the anterior papillary muscle. At this point, it divides and is continuous with the final component of the cardiac conduction system, the subendocardial plexus of ventricular conduction cells or Purkinje fibers. This network of specialized cells spreads throughout the ventricle to supply the ventricular musculature, including the papillary muscles. The left bundle branch passes to the left side of the muscular interventricular septum and descends to the apex of the left ventricle (Fig. 3.83B). Along its course it gives off branches that eventually become continuous with the subendocardial plexus of conduction cells (Purkinje fibers). As with the right side, this network of specialized cells spreads the excitation impulses throughout the left ventricle.
Anatomy_Gray. The right bundle branch continues on the right side of the interventricular septum toward the apex of the right ventricle. From the septum it enters the septomarginal trabecula to reach the base of the anterior papillary muscle. At this point, it divides and is continuous with the final component of the cardiac conduction system, the subendocardial plexus of ventricular conduction cells or Purkinje fibers. This network of specialized cells spreads throughout the ventricle to supply the ventricular musculature, including the papillary muscles. The left bundle branch passes to the left side of the muscular interventricular septum and descends to the apex of the left ventricle (Fig. 3.83B). Along its course it gives off branches that eventually become continuous with the subendocardial plexus of conduction cells (Purkinje fibers). As with the right side, this network of specialized cells spreads the excitation impulses throughout the left ventricle.
Anatomy_Gray_424
Anatomy_Gray
The autonomic division of the peripheral nervous system is directly responsible for regulating: heart rate, force of each contraction, and cardiac output. Branches from both the parasympathetic and sympathetic systems contribute to the formation of the cardiac plexus. This plexus consists of a superficial part, inferior to the aortic arch and between it and the pulmonary trunk (Fig. 3.84A), and a deep part, between the aortic arch and the tracheal bifurcation (Fig. 3.84B). From the cardiac plexus, small branches that are mixed nerves containing both sympathetic and parasympathetic fibers supply the heart. These branches affect nodal tissue and other components of the conduction system, coronary blood vessels, and atrial and ventricular musculature. Stimulation of the parasympathetic system: decreases heart rate, reduces force of contraction, and constricts the coronary arteries.
Anatomy_Gray. The autonomic division of the peripheral nervous system is directly responsible for regulating: heart rate, force of each contraction, and cardiac output. Branches from both the parasympathetic and sympathetic systems contribute to the formation of the cardiac plexus. This plexus consists of a superficial part, inferior to the aortic arch and between it and the pulmonary trunk (Fig. 3.84A), and a deep part, between the aortic arch and the tracheal bifurcation (Fig. 3.84B). From the cardiac plexus, small branches that are mixed nerves containing both sympathetic and parasympathetic fibers supply the heart. These branches affect nodal tissue and other components of the conduction system, coronary blood vessels, and atrial and ventricular musculature. Stimulation of the parasympathetic system: decreases heart rate, reduces force of contraction, and constricts the coronary arteries.
Anatomy_Gray_425
Anatomy_Gray
Stimulation of the parasympathetic system: decreases heart rate, reduces force of contraction, and constricts the coronary arteries. The preganglionic parasympathetic fibers reach the heart as cardiac branches from the right and left vagus nerves. They enter the cardiac plexus and synapse in ganglia located either within the plexus or in the walls of the atria. Stimulation of the sympathetic system: increases heart rate, and increases the force of contraction. Sympathetic fibers reach the cardiac plexus through the cardiac nerves from the sympathetic trunk. Preganglionic sympathetic fibers from the upper four or five segments of the thoracic spinal cord enter and move through the sympathetic trunk. They synapse in cervical and upper thoracic sympathetic ganglia, and postganglionic fibers proceed as bilateral branches from the sympathetic trunk to the cardiac plexus.
Anatomy_Gray. Stimulation of the parasympathetic system: decreases heart rate, reduces force of contraction, and constricts the coronary arteries. The preganglionic parasympathetic fibers reach the heart as cardiac branches from the right and left vagus nerves. They enter the cardiac plexus and synapse in ganglia located either within the plexus or in the walls of the atria. Stimulation of the sympathetic system: increases heart rate, and increases the force of contraction. Sympathetic fibers reach the cardiac plexus through the cardiac nerves from the sympathetic trunk. Preganglionic sympathetic fibers from the upper four or five segments of the thoracic spinal cord enter and move through the sympathetic trunk. They synapse in cervical and upper thoracic sympathetic ganglia, and postganglionic fibers proceed as bilateral branches from the sympathetic trunk to the cardiac plexus.
Anatomy_Gray_426
Anatomy_Gray
Visceral afferents from the heart are also a component of the cardiac plexus. These fibers pass through the cardiac plexus and return to the central nervous system in the cardiac nerves from the sympathetic trunk and in the vagal cardiac branches. The afferents associated with the vagal cardiac nerves return to the vagus nerve [X]. They sense alterations in blood pressure and blood chemistry and are therefore primarily concerned with cardiac reflexes.
Anatomy_Gray. Visceral afferents from the heart are also a component of the cardiac plexus. These fibers pass through the cardiac plexus and return to the central nervous system in the cardiac nerves from the sympathetic trunk and in the vagal cardiac branches. The afferents associated with the vagal cardiac nerves return to the vagus nerve [X]. They sense alterations in blood pressure and blood chemistry and are therefore primarily concerned with cardiac reflexes.
Anatomy_Gray_427
Anatomy_Gray
The afferents associated with the cardiac nerves from the sympathetic trunks return to either the cervical or the thoracic portions of the sympathetic trunk. If they are in the cervical portion of the trunk, they normally descend to the thoracic region, where they reenter the upper four or five thoracic spinal cord segments, along with the afferents from the thoracic region of the sympathetic trunk. Visceral afferents associated with the sympathetic system conduct pain sensation from the heart, which is detected at the cellular level as tissue-damaging events (i.e., cardiac ischemia). This pain is often “referred” to cutaneous regions supplied by the same spinal cord levels (see “In the clinic: Referred pain.” p. 46, and “Case 1,” pp. 244–246).
Anatomy_Gray. The afferents associated with the cardiac nerves from the sympathetic trunks return to either the cervical or the thoracic portions of the sympathetic trunk. If they are in the cervical portion of the trunk, they normally descend to the thoracic region, where they reenter the upper four or five thoracic spinal cord segments, along with the afferents from the thoracic region of the sympathetic trunk. Visceral afferents associated with the sympathetic system conduct pain sensation from the heart, which is detected at the cellular level as tissue-damaging events (i.e., cardiac ischemia). This pain is often “referred” to cutaneous regions supplied by the same spinal cord levels (see “In the clinic: Referred pain.” p. 46, and “Case 1,” pp. 244–246).
Anatomy_Gray_428
Anatomy_Gray
The pulmonary trunk is contained within the pericardial sac (Fig. 3.85), is covered by the visceral layer of serous pericardium, and is associated with the ascending aorta in a common sheath. It arises from the conus arteriosus of the right ventricle at the opening of the pulmonary trunk slightly anterior to the aortic orifice and ascends, moving posteriorly and to the left, lying initially anterior and then to the left of the ascending aorta. At approximately the level of the intervertebral disc between vertebrae TV and TVI, opposite the left border of the sternum and posterior to the third left costal cartilage, the pulmonary trunk divides into: the right pulmonary artery, which passes to the right, posterior to the ascending aorta and the superior vena cava, to enter the right lung; and the left pulmonary artery, which passes inferiorly to the arch of the aorta and anteriorly to the descending aorta to enter the left lung.
Anatomy_Gray. The pulmonary trunk is contained within the pericardial sac (Fig. 3.85), is covered by the visceral layer of serous pericardium, and is associated with the ascending aorta in a common sheath. It arises from the conus arteriosus of the right ventricle at the opening of the pulmonary trunk slightly anterior to the aortic orifice and ascends, moving posteriorly and to the left, lying initially anterior and then to the left of the ascending aorta. At approximately the level of the intervertebral disc between vertebrae TV and TVI, opposite the left border of the sternum and posterior to the third left costal cartilage, the pulmonary trunk divides into: the right pulmonary artery, which passes to the right, posterior to the ascending aorta and the superior vena cava, to enter the right lung; and the left pulmonary artery, which passes inferiorly to the arch of the aorta and anteriorly to the descending aorta to enter the left lung.
Anatomy_Gray_429
Anatomy_Gray
The ascending aorta is contained within the pericardial sac and is covered by a visceral layer of serous pericardium, which also surrounds the pulmonary trunk in a common sheath (Fig. 3.85A). The origin of the ascending aorta is the aortic orifice at the base of the left ventricle, which is level with the lower edge of the third left costal cartilage, posterior to the left half of the sternum. Moving superiorly, slightly forward and to the right, the ascending aorta continues to the level of the second right costal cartilage. At this point, it enters the superior mediastinum and is then referred to as the arch of the aorta. Immediately superior to the point where the ascending aorta arises from the left ventricle are three small outward bulges opposite the semilunar cusps of the aortic valve. These are the posterior, right, and left aortic sinuses. The right and left coronary arteries originate from the right and left aortic sinuses, respectively.
Anatomy_Gray. The ascending aorta is contained within the pericardial sac and is covered by a visceral layer of serous pericardium, which also surrounds the pulmonary trunk in a common sheath (Fig. 3.85A). The origin of the ascending aorta is the aortic orifice at the base of the left ventricle, which is level with the lower edge of the third left costal cartilage, posterior to the left half of the sternum. Moving superiorly, slightly forward and to the right, the ascending aorta continues to the level of the second right costal cartilage. At this point, it enters the superior mediastinum and is then referred to as the arch of the aorta. Immediately superior to the point where the ascending aorta arises from the left ventricle are three small outward bulges opposite the semilunar cusps of the aortic valve. These are the posterior, right, and left aortic sinuses. The right and left coronary arteries originate from the right and left aortic sinuses, respectively.
Anatomy_Gray_430
Anatomy_Gray
The inferior half of the superior vena cava is located within the pericardial sac (Fig. 3.85B). It passes through the fibrous pericardium at approximately the level of the second costal cartilage and enters the right atrium at the lower level of the third costal cartilage. The portion within the pericardial sac is covered with serous pericardium except for a small area on its posterior surface. After passing through the diaphragm, at approximately the level of vertebra TVIII, the inferior vena cava enters the fibrous pericardium. A short portion of this vessel is within the pericardial sac before entering the right atrium. While within the pericardial sac, it is covered by serous pericardium except for a small portion of its posterior surface (Fig. 3.85B).
Anatomy_Gray. The inferior half of the superior vena cava is located within the pericardial sac (Fig. 3.85B). It passes through the fibrous pericardium at approximately the level of the second costal cartilage and enters the right atrium at the lower level of the third costal cartilage. The portion within the pericardial sac is covered with serous pericardium except for a small area on its posterior surface. After passing through the diaphragm, at approximately the level of vertebra TVIII, the inferior vena cava enters the fibrous pericardium. A short portion of this vessel is within the pericardial sac before entering the right atrium. While within the pericardial sac, it is covered by serous pericardium except for a small portion of its posterior surface (Fig. 3.85B).
Anatomy_Gray_431
Anatomy_Gray
A very short segment of each of the pulmonary veins is also within the pericardial sac. These veins, usually two from each lung, pass through the fibrous pericardium and enter the superior region of the left atrium on its posterior surface. In the pericardial sac, all but a portion of the posterior surface of these veins is covered by serous pericardium. In addition, the oblique pericardial sinus is between the right and left pulmonary veins, within the pericardial sac (Fig. 3.85B). The superior mediastinum is posterior to the manubrium of the sternum and anterior to the bodies of the first four thoracic vertebrae (see Fig. 3.57). Its superior boundary is an oblique plane passing from the jugular notch upward and posteriorly to the superior border of vertebra TI. Inferiorly, a transverse plane passing from the sternal angle to the intervertebral disc between vertebra TIV/V separates it from the inferior mediastinum.
Anatomy_Gray. A very short segment of each of the pulmonary veins is also within the pericardial sac. These veins, usually two from each lung, pass through the fibrous pericardium and enter the superior region of the left atrium on its posterior surface. In the pericardial sac, all but a portion of the posterior surface of these veins is covered by serous pericardium. In addition, the oblique pericardial sinus is between the right and left pulmonary veins, within the pericardial sac (Fig. 3.85B). The superior mediastinum is posterior to the manubrium of the sternum and anterior to the bodies of the first four thoracic vertebrae (see Fig. 3.57). Its superior boundary is an oblique plane passing from the jugular notch upward and posteriorly to the superior border of vertebra TI. Inferiorly, a transverse plane passing from the sternal angle to the intervertebral disc between vertebra TIV/V separates it from the inferior mediastinum.
Anatomy_Gray_432
Anatomy_Gray
Inferiorly, a transverse plane passing from the sternal angle to the intervertebral disc between vertebra TIV/V separates it from the inferior mediastinum. Laterally, it is bordered by the mediastinal part of the parietal pleura on either side. The superior mediastinum is continuous with the neck above and with the inferior mediastinum below. The major structures found in the superior mediastinum (Figs. 3.86 and 3.87) include the: thymus, right and left brachiocephalic veins, left superior intercostal vein, superior vena cava, arch of the aorta with its three large branches, trachea, esophagus, phrenic nerves, vagus nerves, left recurrent laryngeal branch of the left vagus nerve, thoracic duct, and other small nerves, blood vessels, and lymphatics. The thymus is the most anterior component of the superior mediastinum, lying immediately posterior to the manubrium of the sternum. It is an asymmetrical, bilobed structure (see Fig. 3.58).
Anatomy_Gray. Inferiorly, a transverse plane passing from the sternal angle to the intervertebral disc between vertebra TIV/V separates it from the inferior mediastinum. Laterally, it is bordered by the mediastinal part of the parietal pleura on either side. The superior mediastinum is continuous with the neck above and with the inferior mediastinum below. The major structures found in the superior mediastinum (Figs. 3.86 and 3.87) include the: thymus, right and left brachiocephalic veins, left superior intercostal vein, superior vena cava, arch of the aorta with its three large branches, trachea, esophagus, phrenic nerves, vagus nerves, left recurrent laryngeal branch of the left vagus nerve, thoracic duct, and other small nerves, blood vessels, and lymphatics. The thymus is the most anterior component of the superior mediastinum, lying immediately posterior to the manubrium of the sternum. It is an asymmetrical, bilobed structure (see Fig. 3.58).
Anatomy_Gray_433
Anatomy_Gray
The thymus is the most anterior component of the superior mediastinum, lying immediately posterior to the manubrium of the sternum. It is an asymmetrical, bilobed structure (see Fig. 3.58). The upper extent of the thymus can reach into the neck as high as the thyroid gland; a lower portion typically extends into the anterior mediastinum over the pericardial sac. Involved in the early development of the immune system, the thymus is a large structure in the child, begins to atrophy after puberty, and shows considerable size variation in the adult. In the elderly adult, it is barely identifiable as an organ, consisting mostly of fatty tissue that is sometimes arranged as two lobulated fatty structures. Arteries to the thymus consist of small branches originating from the internal thoracic arteries. Venous drainage is usually into the left brachiocephalic vein and possibly into the internal thoracic veins.
Anatomy_Gray. The thymus is the most anterior component of the superior mediastinum, lying immediately posterior to the manubrium of the sternum. It is an asymmetrical, bilobed structure (see Fig. 3.58). The upper extent of the thymus can reach into the neck as high as the thyroid gland; a lower portion typically extends into the anterior mediastinum over the pericardial sac. Involved in the early development of the immune system, the thymus is a large structure in the child, begins to atrophy after puberty, and shows considerable size variation in the adult. In the elderly adult, it is barely identifiable as an organ, consisting mostly of fatty tissue that is sometimes arranged as two lobulated fatty structures. Arteries to the thymus consist of small branches originating from the internal thoracic arteries. Venous drainage is usually into the left brachiocephalic vein and possibly into the internal thoracic veins.
Anatomy_Gray_434
Anatomy_Gray
Lymphatic drainage returns to multiple groups of nodes at one or more of the following locations: along the internal thoracic arteries (parasternal); at the tracheal bifurcation (tracheobronchial); and in the root of the neck. The left and right brachiocephalic veins are located immediately posterior to the thymus. They form on each side at the junction between the internal jugular and subclavian veins (see Fig. 3.86). The left brachiocephalic vein crosses the midline and joins with the right brachiocephalic vein to form the superior vena cava (Fig. 3.88). The right brachiocephalic vein begins posterior to the medial end of the right clavicle and passes vertically downward, forming the superior vena cava when it is joined by the left brachiocephalic vein. Venous tributaries include the vertebral, first posterior intercostal, and internal thoracic veins. The inferior thyroid and thymic veins may also drain into it.
Anatomy_Gray. Lymphatic drainage returns to multiple groups of nodes at one or more of the following locations: along the internal thoracic arteries (parasternal); at the tracheal bifurcation (tracheobronchial); and in the root of the neck. The left and right brachiocephalic veins are located immediately posterior to the thymus. They form on each side at the junction between the internal jugular and subclavian veins (see Fig. 3.86). The left brachiocephalic vein crosses the midline and joins with the right brachiocephalic vein to form the superior vena cava (Fig. 3.88). The right brachiocephalic vein begins posterior to the medial end of the right clavicle and passes vertically downward, forming the superior vena cava when it is joined by the left brachiocephalic vein. Venous tributaries include the vertebral, first posterior intercostal, and internal thoracic veins. The inferior thyroid and thymic veins may also drain into it.
Anatomy_Gray_435
Anatomy_Gray
The left brachiocephalic vein begins posterior to the medial end of the left clavicle. It crosses to the right, moving in a slightly inferior direction, and joins with the right brachiocephalic vein to form the superior vena cava posterior to the lower edge of the right first costal cartilage close to the right sternal border. Venous tributaries include the vertebral, first posterior intercostal, left superior intercostal, inferior thyroid, and internal thoracic veins. It may also receive thymic and pericardial veins. The left brachiocephalic vein crosses the midline posterior to the manubrium in the adult. In infants and children the left brachiocephalic vein rises above the superior border of the manubrium and therefore is less protected.
Anatomy_Gray. The left brachiocephalic vein begins posterior to the medial end of the left clavicle. It crosses to the right, moving in a slightly inferior direction, and joins with the right brachiocephalic vein to form the superior vena cava posterior to the lower edge of the right first costal cartilage close to the right sternal border. Venous tributaries include the vertebral, first posterior intercostal, left superior intercostal, inferior thyroid, and internal thoracic veins. It may also receive thymic and pericardial veins. The left brachiocephalic vein crosses the midline posterior to the manubrium in the adult. In infants and children the left brachiocephalic vein rises above the superior border of the manubrium and therefore is less protected.
Anatomy_Gray_436
Anatomy_Gray
The left superior intercostal vein receives the second, third, and sometimes the fourth posterior intercostal veins, usually the left bronchial veins, and sometimes the left pericardiacophrenic vein. It passes over the left side of the aortic arch, lateral to the left vagus nerve and medial to the left phrenic nerve, before entering the left brachiocephalic vein (Fig. 3.89). Inferiorly, it may connect with the accessory hemiazygos vein (superior hemiazygos vein). The vertically oriented superior vena cava begins posterior to the lower edge of the right first costal cartilage, where the right and left brachiocephalic veins join, and terminates at the lower edge of the right third costal cartilage, where it joins the right atrium (see Fig. 3.86). The lower half of the superior vena cava is within the pericardial sac and is therefore contained in the middle mediastinum.
Anatomy_Gray. The left superior intercostal vein receives the second, third, and sometimes the fourth posterior intercostal veins, usually the left bronchial veins, and sometimes the left pericardiacophrenic vein. It passes over the left side of the aortic arch, lateral to the left vagus nerve and medial to the left phrenic nerve, before entering the left brachiocephalic vein (Fig. 3.89). Inferiorly, it may connect with the accessory hemiazygos vein (superior hemiazygos vein). The vertically oriented superior vena cava begins posterior to the lower edge of the right first costal cartilage, where the right and left brachiocephalic veins join, and terminates at the lower edge of the right third costal cartilage, where it joins the right atrium (see Fig. 3.86). The lower half of the superior vena cava is within the pericardial sac and is therefore contained in the middle mediastinum.
Anatomy_Gray_437
Anatomy_Gray
The lower half of the superior vena cava is within the pericardial sac and is therefore contained in the middle mediastinum. The superior vena cava receives the azygos vein immediately before entering the pericardial sac and may also receive pericardial and mediastinal veins. The superior vena cava can be easily visualized forming part of the right superolateral border of the mediastinum on a chest radiograph (see Fig. 3.67A). Arch of aorta and its branches
Anatomy_Gray. The lower half of the superior vena cava is within the pericardial sac and is therefore contained in the middle mediastinum. The superior vena cava receives the azygos vein immediately before entering the pericardial sac and may also receive pericardial and mediastinal veins. The superior vena cava can be easily visualized forming part of the right superolateral border of the mediastinum on a chest radiograph (see Fig. 3.67A). Arch of aorta and its branches
Anatomy_Gray_438
Anatomy_Gray
The superior vena cava can be easily visualized forming part of the right superolateral border of the mediastinum on a chest radiograph (see Fig. 3.67A). Arch of aorta and its branches The thoracic portion of the aorta can be divided into ascending aorta, arch of the aorta, and thoracic (descending) aorta. Only the arch of the aorta is in the superior mediastinum. It begins when the ascending aorta emerges from the pericardial sac and courses upward, backward, and to the left as it passes through the superior mediastinum, ending on the left side at vertebral level TIV/V (see Fig. 3.86). Extending as high as the midlevel of the manubrium of the sternum, the arch is initially anterior and finally lateral to the trachea. Three branches arise from the superior border of the arch of the aorta; at their origins, all three are crossed anteriorly by the left brachiocephalic vein. The first branch
Anatomy_Gray. The superior vena cava can be easily visualized forming part of the right superolateral border of the mediastinum on a chest radiograph (see Fig. 3.67A). Arch of aorta and its branches The thoracic portion of the aorta can be divided into ascending aorta, arch of the aorta, and thoracic (descending) aorta. Only the arch of the aorta is in the superior mediastinum. It begins when the ascending aorta emerges from the pericardial sac and courses upward, backward, and to the left as it passes through the superior mediastinum, ending on the left side at vertebral level TIV/V (see Fig. 3.86). Extending as high as the midlevel of the manubrium of the sternum, the arch is initially anterior and finally lateral to the trachea. Three branches arise from the superior border of the arch of the aorta; at their origins, all three are crossed anteriorly by the left brachiocephalic vein. The first branch
Anatomy_Gray_439
Anatomy_Gray
Three branches arise from the superior border of the arch of the aorta; at their origins, all three are crossed anteriorly by the left brachiocephalic vein. The first branch Beginning on the right, the first branch of the arch of the aorta is the brachiocephalic trunk (Fig. 3.90). It is the largest of the three branches and, at its point of origin behind the manubrium of the sternum, is slightly anterior to the other two branches. It ascends slightly posteriorly and to the right. At the level of the upper edge of the right sternoclavicular joint, the brachiocephalic trunk divides into: the right common carotid artery, and the right subclavian artery (see Fig. 3.86). The arteries mainly supply the right side of the head and neck and the right upper limb, respectively. Occasionally, the brachiocephalic trunk has a small branch, the thyroid ima artery, which contributes to the vascular supply of the thyroid gland. The second branch
Anatomy_Gray. Three branches arise from the superior border of the arch of the aorta; at their origins, all three are crossed anteriorly by the left brachiocephalic vein. The first branch Beginning on the right, the first branch of the arch of the aorta is the brachiocephalic trunk (Fig. 3.90). It is the largest of the three branches and, at its point of origin behind the manubrium of the sternum, is slightly anterior to the other two branches. It ascends slightly posteriorly and to the right. At the level of the upper edge of the right sternoclavicular joint, the brachiocephalic trunk divides into: the right common carotid artery, and the right subclavian artery (see Fig. 3.86). The arteries mainly supply the right side of the head and neck and the right upper limb, respectively. Occasionally, the brachiocephalic trunk has a small branch, the thyroid ima artery, which contributes to the vascular supply of the thyroid gland. The second branch
Anatomy_Gray_440
Anatomy_Gray
Occasionally, the brachiocephalic trunk has a small branch, the thyroid ima artery, which contributes to the vascular supply of the thyroid gland. The second branch The second branch of the arch of the aorta is the left common carotid artery (Fig. 3.90). It arises from the arch immediately to the left and slightly posterior to the brachiocephalic trunk and ascends through the superior mediastinum along the left side of the trachea. The left common carotid artery supplies the left side of the head and neck. The third branch The third branch of the arch of the aorta is the left subclavian artery (Fig. 3.90). It arises from the arch of the aorta immediately to the left of, and slightly posterior to, the left common carotid artery and ascends through the superior mediastinum along the left side of the trachea. The left subclavian artery is the major blood supply to the left upper limb.
Anatomy_Gray. Occasionally, the brachiocephalic trunk has a small branch, the thyroid ima artery, which contributes to the vascular supply of the thyroid gland. The second branch The second branch of the arch of the aorta is the left common carotid artery (Fig. 3.90). It arises from the arch immediately to the left and slightly posterior to the brachiocephalic trunk and ascends through the superior mediastinum along the left side of the trachea. The left common carotid artery supplies the left side of the head and neck. The third branch The third branch of the arch of the aorta is the left subclavian artery (Fig. 3.90). It arises from the arch of the aorta immediately to the left of, and slightly posterior to, the left common carotid artery and ascends through the superior mediastinum along the left side of the trachea. The left subclavian artery is the major blood supply to the left upper limb.
Anatomy_Gray_441
Anatomy_Gray
The left subclavian artery is the major blood supply to the left upper limb. The ligamentum arteriosum is also in the superior mediastinum and is important in embryonic circulation, when it is a patent vessel (the ductus arteriosus). It connects the pulmonary trunk with the arch of the aorta and allows blood to bypass the lungs during development (Fig. 3.90). The vessel closes soon after birth and forms the ligamentous connection observed in the adult. The trachea is a midline structure that is palpable in the jugular notch as it enters the superior mediastinum. Posterior to it is the esophagus, which is immediately anterior to the vertebral column (Fig. 3.92, and see Figs. 3.86 and 3.87). Significant mobility exists in the vertical positioning of these structures as they pass through the superior mediastinum. Swallowing and breathing cause positional shifts, as may disease and the use of specialized instrumentation.
Anatomy_Gray. The left subclavian artery is the major blood supply to the left upper limb. The ligamentum arteriosum is also in the superior mediastinum and is important in embryonic circulation, when it is a patent vessel (the ductus arteriosus). It connects the pulmonary trunk with the arch of the aorta and allows blood to bypass the lungs during development (Fig. 3.90). The vessel closes soon after birth and forms the ligamentous connection observed in the adult. The trachea is a midline structure that is palpable in the jugular notch as it enters the superior mediastinum. Posterior to it is the esophagus, which is immediately anterior to the vertebral column (Fig. 3.92, and see Figs. 3.86 and 3.87). Significant mobility exists in the vertical positioning of these structures as they pass through the superior mediastinum. Swallowing and breathing cause positional shifts, as may disease and the use of specialized instrumentation.
Anatomy_Gray_442
Anatomy_Gray
As the trachea and esophagus pass through the superior mediastinum, they are crossed laterally by the azygos vein on the right side and the arch of the aorta on the left side. The trachea divides into the right and left main bronchi at, or just inferior to, the transverse plane between the sternal angle and vertebral level TIV/V (Fig. 3.93), whereas the esophagus continues into the posterior mediastinum. Nerves of the superior mediastinum The vagus nerves [X] pass through the superior and posterior divisions of the mediastinum on their way to the abdominal cavity. As they pass through the thorax, they provide parasympathetic innervation to the thoracic viscera and carry visceral afferents from the thoracic viscera. Visceral afferents in the vagus nerves relay information to the central nervous system about normal physiological processes and reflex activities. They do not transmit pain sensation.
Anatomy_Gray. As the trachea and esophagus pass through the superior mediastinum, they are crossed laterally by the azygos vein on the right side and the arch of the aorta on the left side. The trachea divides into the right and left main bronchi at, or just inferior to, the transverse plane between the sternal angle and vertebral level TIV/V (Fig. 3.93), whereas the esophagus continues into the posterior mediastinum. Nerves of the superior mediastinum The vagus nerves [X] pass through the superior and posterior divisions of the mediastinum on their way to the abdominal cavity. As they pass through the thorax, they provide parasympathetic innervation to the thoracic viscera and carry visceral afferents from the thoracic viscera. Visceral afferents in the vagus nerves relay information to the central nervous system about normal physiological processes and reflex activities. They do not transmit pain sensation.
Anatomy_Gray_443
Anatomy_Gray
Visceral afferents in the vagus nerves relay information to the central nervous system about normal physiological processes and reflex activities. They do not transmit pain sensation. The right vagus nerve enters the superior mediastinum and lies between the right brachiocephalic vein and the brachiocephalic trunk. It descends in a posterior direction toward the trachea (Fig. 3.94), crosses the lateral surface of the trachea, and passes posteriorly to the root of the right lung to reach the esophagus. Just before the esophagus, it is crossed by the arch of the azygos vein. As the right vagus nerve passes through the superior mediastinum, it gives branches to the esophagus, cardiac plexus, and pulmonary plexus.
Anatomy_Gray. Visceral afferents in the vagus nerves relay information to the central nervous system about normal physiological processes and reflex activities. They do not transmit pain sensation. The right vagus nerve enters the superior mediastinum and lies between the right brachiocephalic vein and the brachiocephalic trunk. It descends in a posterior direction toward the trachea (Fig. 3.94), crosses the lateral surface of the trachea, and passes posteriorly to the root of the right lung to reach the esophagus. Just before the esophagus, it is crossed by the arch of the azygos vein. As the right vagus nerve passes through the superior mediastinum, it gives branches to the esophagus, cardiac plexus, and pulmonary plexus.
Anatomy_Gray_444
Anatomy_Gray
As the right vagus nerve passes through the superior mediastinum, it gives branches to the esophagus, cardiac plexus, and pulmonary plexus. The left vagus nerve enters the superior mediastinum posterior to the left brachiocephalic vein and between the left common carotid and left subclavian arteries (Fig. 3.95). As it passes into the superior mediastinum, it lies just deep to the mediastinal part of the parietal pleura and crosses the left side of the arch of the aorta. It continues to descend in a posterior direction and passes posterior to the root of the left lung to reach the esophagus in the posterior mediastinum. As the left vagus nerve passes through the superior mediastinum, it gives branches to the esophagus, the cardiac plexus, and the pulmonary plexus.
Anatomy_Gray. As the right vagus nerve passes through the superior mediastinum, it gives branches to the esophagus, cardiac plexus, and pulmonary plexus. The left vagus nerve enters the superior mediastinum posterior to the left brachiocephalic vein and between the left common carotid and left subclavian arteries (Fig. 3.95). As it passes into the superior mediastinum, it lies just deep to the mediastinal part of the parietal pleura and crosses the left side of the arch of the aorta. It continues to descend in a posterior direction and passes posterior to the root of the left lung to reach the esophagus in the posterior mediastinum. As the left vagus nerve passes through the superior mediastinum, it gives branches to the esophagus, the cardiac plexus, and the pulmonary plexus.
Anatomy_Gray_445
Anatomy_Gray
As the left vagus nerve passes through the superior mediastinum, it gives branches to the esophagus, the cardiac plexus, and the pulmonary plexus. The left vagus nerve also gives rise to the left recurrent laryngeal nerve, which arises from it at the inferior margin of the arch of the aorta just lateral to the ligamentum arteriosum. The left recurrent laryngeal nerve passes inferior to the arch of the aorta before ascending on its medial surface. Entering a groove between the trachea and esophagus, the left recurrent laryngeal nerve continues superiorly to enter the neck and terminate in the larynx (Fig. 3.96). The phrenic nerves arise in the cervical region mainly from the fourth, but also from the third and fifth, cervical spinal cord segments.
Anatomy_Gray. As the left vagus nerve passes through the superior mediastinum, it gives branches to the esophagus, the cardiac plexus, and the pulmonary plexus. The left vagus nerve also gives rise to the left recurrent laryngeal nerve, which arises from it at the inferior margin of the arch of the aorta just lateral to the ligamentum arteriosum. The left recurrent laryngeal nerve passes inferior to the arch of the aorta before ascending on its medial surface. Entering a groove between the trachea and esophagus, the left recurrent laryngeal nerve continues superiorly to enter the neck and terminate in the larynx (Fig. 3.96). The phrenic nerves arise in the cervical region mainly from the fourth, but also from the third and fifth, cervical spinal cord segments.
Anatomy_Gray_446
Anatomy_Gray
The phrenic nerves arise in the cervical region mainly from the fourth, but also from the third and fifth, cervical spinal cord segments. The phrenic nerves descend through the thorax to supply motor and sensory innervation to the diaphragm and its associated membranes. As they pass through the thorax, they provide innervation through somatic afferent fibers to the mediastinal pleura, fibrous pericardium, and parietal layer of serous pericardium. The right phrenic nerve enters the superior mediastinum lateral to the right vagus nerve and lateral and slightly posterior to the beginning of the right brachiocephalic vein (see Fig. 3.94). It continues inferiorly along the right side of this vein and the right side of the superior vena cava.
Anatomy_Gray. The phrenic nerves arise in the cervical region mainly from the fourth, but also from the third and fifth, cervical spinal cord segments. The phrenic nerves descend through the thorax to supply motor and sensory innervation to the diaphragm and its associated membranes. As they pass through the thorax, they provide innervation through somatic afferent fibers to the mediastinal pleura, fibrous pericardium, and parietal layer of serous pericardium. The right phrenic nerve enters the superior mediastinum lateral to the right vagus nerve and lateral and slightly posterior to the beginning of the right brachiocephalic vein (see Fig. 3.94). It continues inferiorly along the right side of this vein and the right side of the superior vena cava.
Anatomy_Gray_447
Anatomy_Gray
On entering the middle mediastinum, the right phrenic nerve descends along the right side of the pericardial sac, within the fibrous pericardium, anterior to the root of the right lung. The pericardiacophrenic vessels accompany it through most of its course in the thorax (see Fig. 3.60). It leaves the thorax by passing through the diaphragm with the inferior vena cava. The left phrenic nerve enters the superior mediastinum in a position similar to the path taken by the right phrenic nerve. It lies lateral to the left vagus nerve and lateral and slightly posterior to the beginning of the left brachiocephalic vein (see Fig. 3.89), and continues to descend across the left lateral surface of the arch of the aorta, passing superficially to the left vagus nerve and the left superior intercostal vein.
Anatomy_Gray. On entering the middle mediastinum, the right phrenic nerve descends along the right side of the pericardial sac, within the fibrous pericardium, anterior to the root of the right lung. The pericardiacophrenic vessels accompany it through most of its course in the thorax (see Fig. 3.60). It leaves the thorax by passing through the diaphragm with the inferior vena cava. The left phrenic nerve enters the superior mediastinum in a position similar to the path taken by the right phrenic nerve. It lies lateral to the left vagus nerve and lateral and slightly posterior to the beginning of the left brachiocephalic vein (see Fig. 3.89), and continues to descend across the left lateral surface of the arch of the aorta, passing superficially to the left vagus nerve and the left superior intercostal vein.
Anatomy_Gray_448
Anatomy_Gray
On entering the middle mediastinum, the left phrenic nerve follows the left side of the pericardial sac, within the fibrous pericardium, anterior to the root of the left lung, and is accompanied by the pericardiacophrenic vessels (see Fig. 3.60). It leaves the thorax by piercing the diaphragm near the apex of the heart. Thoracic duct in the superior mediastinum The thoracic duct, which is the major lymphatic vessel in the body, passes through the posterior portion of the superior mediastinum (see Figs. 3.87 and 3.92). It: enters the superior mediastinum inferiorly, slightly to the left of the midline, having moved to this position just before leaving the posterior mediastinum opposite vertebral level TIV/V; and continues through the superior mediastinum, posterior to the arch of the aorta, and the initial portion of the left subclavian artery, between the esophagus and the left mediastinal part of the parietal pleura.
Anatomy_Gray. On entering the middle mediastinum, the left phrenic nerve follows the left side of the pericardial sac, within the fibrous pericardium, anterior to the root of the left lung, and is accompanied by the pericardiacophrenic vessels (see Fig. 3.60). It leaves the thorax by piercing the diaphragm near the apex of the heart. Thoracic duct in the superior mediastinum The thoracic duct, which is the major lymphatic vessel in the body, passes through the posterior portion of the superior mediastinum (see Figs. 3.87 and 3.92). It: enters the superior mediastinum inferiorly, slightly to the left of the midline, having moved to this position just before leaving the posterior mediastinum opposite vertebral level TIV/V; and continues through the superior mediastinum, posterior to the arch of the aorta, and the initial portion of the left subclavian artery, between the esophagus and the left mediastinal part of the parietal pleura.
Anatomy_Gray_449
Anatomy_Gray
The posterior mediastinum is posterior to the pericardial sac and diaphragm and anterior to the bodies of the mid and lower thoracic vertebrae (see Fig. 3.57). Its superior boundary is a transverse plane passing from the sternal angle to the intervertebral disc between vertebrae TIV and TV. Its inferior boundary is the diaphragm. Laterally, it is bordered by the mediastinal part of parietal pleura on either side. Superiorly, it is continuous with the superior mediastinum. Major structures in the posterior mediastinum include the: esophagus and its associated nerve plexus, thoracic aorta and its branches, azygos system of veins, thoracic duct and associated lymph nodes, sympathetic trunks, and thoracic splanchnic nerves. The esophagus is a muscular tube passing between the pharynx in the neck and the stomach in the abdomen. It begins at the inferior border of the cricoid cartilage, opposite vertebra CVI, and ends at the cardiac opening of the stomach, opposite vertebra TXI.
Anatomy_Gray. The posterior mediastinum is posterior to the pericardial sac and diaphragm and anterior to the bodies of the mid and lower thoracic vertebrae (see Fig. 3.57). Its superior boundary is a transverse plane passing from the sternal angle to the intervertebral disc between vertebrae TIV and TV. Its inferior boundary is the diaphragm. Laterally, it is bordered by the mediastinal part of parietal pleura on either side. Superiorly, it is continuous with the superior mediastinum. Major structures in the posterior mediastinum include the: esophagus and its associated nerve plexus, thoracic aorta and its branches, azygos system of veins, thoracic duct and associated lymph nodes, sympathetic trunks, and thoracic splanchnic nerves. The esophagus is a muscular tube passing between the pharynx in the neck and the stomach in the abdomen. It begins at the inferior border of the cricoid cartilage, opposite vertebra CVI, and ends at the cardiac opening of the stomach, opposite vertebra TXI.
Anatomy_Gray_450
Anatomy_Gray
The esophagus descends on the anterior aspect of the bodies of the vertebrae, generally in a midline position as it moves through the thorax (Fig. 3.97). As it approaches the diaphragm, it moves anteriorly and to the left, crossing from the right side of the thoracic aorta to eventually assume a position anterior to it. It then passes through the esophageal hiatus, an opening in the muscular part of the diaphragm, at vertebral level TX. The esophagus has a slight anterior-to-posterior curvature that parallels the thoracic portion of the vertebral column, and is secured superiorly by its attachment to the pharynx and inferiorly by its attachment to the diaphragm. Relationships to important structures in the posterior mediastinum In the posterior mediastinum, the esophagus is related to a number of important structures. The right side is covered by the mediastinal part of the parietal pleura.
Anatomy_Gray. The esophagus descends on the anterior aspect of the bodies of the vertebrae, generally in a midline position as it moves through the thorax (Fig. 3.97). As it approaches the diaphragm, it moves anteriorly and to the left, crossing from the right side of the thoracic aorta to eventually assume a position anterior to it. It then passes through the esophageal hiatus, an opening in the muscular part of the diaphragm, at vertebral level TX. The esophagus has a slight anterior-to-posterior curvature that parallels the thoracic portion of the vertebral column, and is secured superiorly by its attachment to the pharynx and inferiorly by its attachment to the diaphragm. Relationships to important structures in the posterior mediastinum In the posterior mediastinum, the esophagus is related to a number of important structures. The right side is covered by the mediastinal part of the parietal pleura.
Anatomy_Gray_451
Anatomy_Gray
In the posterior mediastinum, the esophagus is related to a number of important structures. The right side is covered by the mediastinal part of the parietal pleura. Posterior to the esophagus, the thoracic duct is on the right side inferiorly, but crosses to the left more superiorly. Also on the left side of the esophagus is the thoracic aorta. Anterior to the esophagus, below the level of the tracheal bifurcation, are the right pulmonary artery and the left main bronchus. The esophagus then passes immediately posteriorly to the left atrium, separated from it only by pericardium. Inferior to the left atrium, the esophagus is related to the diaphragm. Structures other than the thoracic duct posterior to the esophagus include portions of the hemiazygos veins, the right posterior intercostal vessels, and, near the diaphragm, the thoracic aorta.
Anatomy_Gray. In the posterior mediastinum, the esophagus is related to a number of important structures. The right side is covered by the mediastinal part of the parietal pleura. Posterior to the esophagus, the thoracic duct is on the right side inferiorly, but crosses to the left more superiorly. Also on the left side of the esophagus is the thoracic aorta. Anterior to the esophagus, below the level of the tracheal bifurcation, are the right pulmonary artery and the left main bronchus. The esophagus then passes immediately posteriorly to the left atrium, separated from it only by pericardium. Inferior to the left atrium, the esophagus is related to the diaphragm. Structures other than the thoracic duct posterior to the esophagus include portions of the hemiazygos veins, the right posterior intercostal vessels, and, near the diaphragm, the thoracic aorta.
Anatomy_Gray_452
Anatomy_Gray
Structures other than the thoracic duct posterior to the esophagus include portions of the hemiazygos veins, the right posterior intercostal vessels, and, near the diaphragm, the thoracic aorta. The esophagus is a flexible, muscular tube that can be compressed or narrowed by surrounding structures at four locations (Fig. 3.98): the junction of the esophagus with the pharynx in the neck; in the superior mediastinum where the esophagus is crossed by the arch of the aorta; in the posterior mediastinum where the esophagus is compressed by the left main bronchus; in the posterior mediastinum at the esophageal hiatus in the diaphragm.
Anatomy_Gray. Structures other than the thoracic duct posterior to the esophagus include portions of the hemiazygos veins, the right posterior intercostal vessels, and, near the diaphragm, the thoracic aorta. The esophagus is a flexible, muscular tube that can be compressed or narrowed by surrounding structures at four locations (Fig. 3.98): the junction of the esophagus with the pharynx in the neck; in the superior mediastinum where the esophagus is crossed by the arch of the aorta; in the posterior mediastinum where the esophagus is compressed by the left main bronchus; in the posterior mediastinum at the esophageal hiatus in the diaphragm.
Anatomy_Gray_453
Anatomy_Gray
These constrictions have important clinical consequences. For example, a swallowed object is most likely to lodge at a constricted area. An ingested corrosive substance would move more slowly through a narrowed region, causing more damage at this site than elsewhere along the esophagus. Also, constrictions present problems during the passage of medical instruments. The arterial supply and venous drainage of the esophagus in the posterior mediastinum involve many vessels. Esophageal arteries arise from the thoracic aorta, bronchial arteries, and ascending branches of the left gastric artery in the abdomen. Venous drainage involves small vessels returning to the azygos vein, hemiazygos vein, and esophageal branches to the left gastric vein in the abdomen. Lymphatic drainage of the esophagus in the posterior mediastinum returns to posterior mediastinal and left gastric nodes.
Anatomy_Gray. These constrictions have important clinical consequences. For example, a swallowed object is most likely to lodge at a constricted area. An ingested corrosive substance would move more slowly through a narrowed region, causing more damage at this site than elsewhere along the esophagus. Also, constrictions present problems during the passage of medical instruments. The arterial supply and venous drainage of the esophagus in the posterior mediastinum involve many vessels. Esophageal arteries arise from the thoracic aorta, bronchial arteries, and ascending branches of the left gastric artery in the abdomen. Venous drainage involves small vessels returning to the azygos vein, hemiazygos vein, and esophageal branches to the left gastric vein in the abdomen. Lymphatic drainage of the esophagus in the posterior mediastinum returns to posterior mediastinal and left gastric nodes.
Anatomy_Gray_454
Anatomy_Gray
Lymphatic drainage of the esophagus in the posterior mediastinum returns to posterior mediastinal and left gastric nodes. Innervation of the esophagus, in general, is complex. Esophageal branches arise from the vagus nerves and sympathetic trunks. Striated muscle fibers in the superior portion of the esophagus originate from the branchial arches and are innervated by branchial efferents from the vagus nerves. Smooth muscle fibers are innervated by cranial components of the parasympathetic part of the autonomic division of the peripheral nervous system, visceral efferents from the vagus nerves. These are preganglionic fibers that synapse in the myenteric and submucosal plexuses of the enteric nervous system in the esophageal wall. Sensory innervation of the esophagus involves visceral afferent fibers originating in the vagus nerves, sympathetic trunks, and splanchnic nerves.
Anatomy_Gray. Lymphatic drainage of the esophagus in the posterior mediastinum returns to posterior mediastinal and left gastric nodes. Innervation of the esophagus, in general, is complex. Esophageal branches arise from the vagus nerves and sympathetic trunks. Striated muscle fibers in the superior portion of the esophagus originate from the branchial arches and are innervated by branchial efferents from the vagus nerves. Smooth muscle fibers are innervated by cranial components of the parasympathetic part of the autonomic division of the peripheral nervous system, visceral efferents from the vagus nerves. These are preganglionic fibers that synapse in the myenteric and submucosal plexuses of the enteric nervous system in the esophageal wall. Sensory innervation of the esophagus involves visceral afferent fibers originating in the vagus nerves, sympathetic trunks, and splanchnic nerves.
Anatomy_Gray_455
Anatomy_Gray
Sensory innervation of the esophagus involves visceral afferent fibers originating in the vagus nerves, sympathetic trunks, and splanchnic nerves. The visceral afferents from the vagus nerves are involved in relaying information back to the central nervous system about normal physiological processes and reflex activities. They are not involved in the relay of pain recognition. The visceral afferents that pass through the sympathetic trunks and the splanchnic nerves are the primary participants in detection of esophageal pain and transmission of this information to various levels of the central nervous system.
Anatomy_Gray. Sensory innervation of the esophagus involves visceral afferent fibers originating in the vagus nerves, sympathetic trunks, and splanchnic nerves. The visceral afferents from the vagus nerves are involved in relaying information back to the central nervous system about normal physiological processes and reflex activities. They are not involved in the relay of pain recognition. The visceral afferents that pass through the sympathetic trunks and the splanchnic nerves are the primary participants in detection of esophageal pain and transmission of this information to various levels of the central nervous system.
Anatomy_Gray_456
Anatomy_Gray
After passing posteriorly to the root of the lungs, the right and left vagus nerves approach the esophagus. As they reach the esophagus, each nerve divides into several branches that spread over this structure, forming the esophageal plexus (Fig. 3.99). There is some mixing of fibers from the two vagus nerves as the plexus continues inferiorly on the esophagus toward the diaphragm. Just above the diaphragm, fibers of the plexus converge to form two trunks: the anterior vagal trunk on the anterior surface of the esophagus, mainly from fibers originally in the left vagus nerve; the posterior vagal trunk on the posterior surface of the esophagus, mainly from fibers originally in the right vagus nerve. The vagal trunks continue on the surface of the esophagus as it passes through the diaphragm into the abdomen.
Anatomy_Gray. After passing posteriorly to the root of the lungs, the right and left vagus nerves approach the esophagus. As they reach the esophagus, each nerve divides into several branches that spread over this structure, forming the esophageal plexus (Fig. 3.99). There is some mixing of fibers from the two vagus nerves as the plexus continues inferiorly on the esophagus toward the diaphragm. Just above the diaphragm, fibers of the plexus converge to form two trunks: the anterior vagal trunk on the anterior surface of the esophagus, mainly from fibers originally in the left vagus nerve; the posterior vagal trunk on the posterior surface of the esophagus, mainly from fibers originally in the right vagus nerve. The vagal trunks continue on the surface of the esophagus as it passes through the diaphragm into the abdomen.
Anatomy_Gray_457
Anatomy_Gray
The vagal trunks continue on the surface of the esophagus as it passes through the diaphragm into the abdomen. The thoracic portion of the descending aorta (thoracic aorta) begins at the lower edge of vertebra TIV, where it is continuous with the arch of the aorta. It ends anterior to the lower edge of vertebra TXII, where it passes through the aortic hiatus posterior to the diaphragm. Situated to the left of the vertebral column superiorly, it approaches the midline inferiorly, lying directly anterior to the lower thoracic vertebral bodies (Fig. 3.101). Throughout its course, it gives off a number of branches, which are summarized in Table 3.3. Azygos system of veins
Anatomy_Gray. The vagal trunks continue on the surface of the esophagus as it passes through the diaphragm into the abdomen. The thoracic portion of the descending aorta (thoracic aorta) begins at the lower edge of vertebra TIV, where it is continuous with the arch of the aorta. It ends anterior to the lower edge of vertebra TXII, where it passes through the aortic hiatus posterior to the diaphragm. Situated to the left of the vertebral column superiorly, it approaches the midline inferiorly, lying directly anterior to the lower thoracic vertebral bodies (Fig. 3.101). Throughout its course, it gives off a number of branches, which are summarized in Table 3.3. Azygos system of veins
Anatomy_Gray_458
Anatomy_Gray
Azygos system of veins The azygos system of veins consists of a series of longitudinal vessels on each side of the body that drain blood from the body wall and move it superiorly to empty into the superior vena cava. Blood from some of the thoracic viscera may also enter the system, and there are anastomotic connections with abdominal veins. The longitudinal vessels may or may not be continuous and are connected to each other from side to side at various points throughout their course (Fig. 3.102). The azygos system of veins serves as an important anastomotic pathway capable of returning venous blood from the lower part of the body to the heart if the inferior vena cava is blocked. The major veins in the system are: the azygos vein, on the right; and the hemiazygos vein and the accessory hemiazygos vein, on the left. There is significant variation in the origin, course, tributaries, anastomoses, and termination of these vessels.
Anatomy_Gray. Azygos system of veins The azygos system of veins consists of a series of longitudinal vessels on each side of the body that drain blood from the body wall and move it superiorly to empty into the superior vena cava. Blood from some of the thoracic viscera may also enter the system, and there are anastomotic connections with abdominal veins. The longitudinal vessels may or may not be continuous and are connected to each other from side to side at various points throughout their course (Fig. 3.102). The azygos system of veins serves as an important anastomotic pathway capable of returning venous blood from the lower part of the body to the heart if the inferior vena cava is blocked. The major veins in the system are: the azygos vein, on the right; and the hemiazygos vein and the accessory hemiazygos vein, on the left. There is significant variation in the origin, course, tributaries, anastomoses, and termination of these vessels.
Anatomy_Gray_459
Anatomy_Gray
There is significant variation in the origin, course, tributaries, anastomoses, and termination of these vessels. The azygos vein arises opposite vertebra LI or LII at the junction between the right ascending lumbar vein and the right subcostal vein (Fig. 3.102). It may also arise as a direct branch of the inferior vena cava, which is joined by a common trunk from the junction of the right ascending lumbar vein and the right subcostal vein. The azygos vein enters the thorax through the aortic hiatus of the diaphragm, or it enters through or posterior to the right crus of the diaphragm. It ascends through the posterior mediastinum, usually to the right of the thoracic duct. At approximately vertebral level TIV, it arches anteriorly, over the root of the right lung, to join the superior vena cava before the superior vena cava enters the pericardial sac.
Anatomy_Gray. There is significant variation in the origin, course, tributaries, anastomoses, and termination of these vessels. The azygos vein arises opposite vertebra LI or LII at the junction between the right ascending lumbar vein and the right subcostal vein (Fig. 3.102). It may also arise as a direct branch of the inferior vena cava, which is joined by a common trunk from the junction of the right ascending lumbar vein and the right subcostal vein. The azygos vein enters the thorax through the aortic hiatus of the diaphragm, or it enters through or posterior to the right crus of the diaphragm. It ascends through the posterior mediastinum, usually to the right of the thoracic duct. At approximately vertebral level TIV, it arches anteriorly, over the root of the right lung, to join the superior vena cava before the superior vena cava enters the pericardial sac.
Anatomy_Gray_460
Anatomy_Gray
Tributaries of the azygos vein include: the right superior intercostal vein (a single vessel formed by the junction of the second, third, and fourth intercostal veins), fifth to eleventh right posterior intercostal veins, the hemiazygos vein, the accessory hemiazygos vein, esophageal veins, mediastinal veins, pericardial veins, and right bronchial veins. The hemiazygos vein (inferior hemiazygos vein) usually arises at the junction between the left ascending lumbar vein and the left subcostal vein (Fig. 3.102). It may also arise from either of these veins alone and often has a connection to the left renal vein. The hemiazygos vein usually enters the thorax through the left crus of the diaphragm, but may enter through the aortic hiatus. It ascends through the posterior mediastinum, on the left side, to approximately vertebral level TIX. At this point, it crosses the vertebral column, posterior to the thoracic aorta, esophagus, and thoracic duct, to enter the azygos vein.
Anatomy_Gray. Tributaries of the azygos vein include: the right superior intercostal vein (a single vessel formed by the junction of the second, third, and fourth intercostal veins), fifth to eleventh right posterior intercostal veins, the hemiazygos vein, the accessory hemiazygos vein, esophageal veins, mediastinal veins, pericardial veins, and right bronchial veins. The hemiazygos vein (inferior hemiazygos vein) usually arises at the junction between the left ascending lumbar vein and the left subcostal vein (Fig. 3.102). It may also arise from either of these veins alone and often has a connection to the left renal vein. The hemiazygos vein usually enters the thorax through the left crus of the diaphragm, but may enter through the aortic hiatus. It ascends through the posterior mediastinum, on the left side, to approximately vertebral level TIX. At this point, it crosses the vertebral column, posterior to the thoracic aorta, esophagus, and thoracic duct, to enter the azygos vein.
Anatomy_Gray_461
Anatomy_Gray
Tributaries joining the hemiazygos vein include: the lowest four or five left posterior intercostal veins, esophageal veins, and mediastinal veins. The accessory hemiazygos vein (superior hemiazygos vein) descends on the left side from the superior portion of the posterior mediastinum to approximately vertebral level TVIII (Fig. 3.102). At this point, it crosses the vertebral column to join the azygos vein, or ends in the hemiazygos vein, or has a connection to both veins. Usually, it also has a connection superiorly to the left superior intercostal vein. Vessels that drain into the accessory hemiazygos vein include: the fourth to eighth left posterior intercostal veins, and sometimes, the left bronchial veins. Thoracic duct in the posterior mediastinum
Anatomy_Gray. Tributaries joining the hemiazygos vein include: the lowest four or five left posterior intercostal veins, esophageal veins, and mediastinal veins. The accessory hemiazygos vein (superior hemiazygos vein) descends on the left side from the superior portion of the posterior mediastinum to approximately vertebral level TVIII (Fig. 3.102). At this point, it crosses the vertebral column to join the azygos vein, or ends in the hemiazygos vein, or has a connection to both veins. Usually, it also has a connection superiorly to the left superior intercostal vein. Vessels that drain into the accessory hemiazygos vein include: the fourth to eighth left posterior intercostal veins, and sometimes, the left bronchial veins. Thoracic duct in the posterior mediastinum
Anatomy_Gray_462
Anatomy_Gray
Thoracic duct in the posterior mediastinum The thoracic duct is the principal channel through which lymph from most of the body is returned to the venous system. It begins as a confluence of lymph trunks in the abdomen, sometimes forming a saccular dilation referred to as the cisterna chyli (chyle cistern), which drains the abdominal viscera and walls, pelvis, perineum, and lower limbs. The thoracic duct extends from vertebra LII to the root of the neck. Entering the thorax, posterior to the aorta, through the aortic hiatus of the diaphragm, the thoracic duct ascends through the posterior mediastinum to the right of midline between the thoracic aorta on the left and the azygos vein on the right (Fig. 3.103). It lies posterior to the diaphragm and the esophagus and anterior to the bodies of the vertebrae. At vertebral level TV, the thoracic duct moves to the left of midline and enters the superior mediastinum. It continues through the superior mediastinum and into the neck.
Anatomy_Gray. Thoracic duct in the posterior mediastinum The thoracic duct is the principal channel through which lymph from most of the body is returned to the venous system. It begins as a confluence of lymph trunks in the abdomen, sometimes forming a saccular dilation referred to as the cisterna chyli (chyle cistern), which drains the abdominal viscera and walls, pelvis, perineum, and lower limbs. The thoracic duct extends from vertebra LII to the root of the neck. Entering the thorax, posterior to the aorta, through the aortic hiatus of the diaphragm, the thoracic duct ascends through the posterior mediastinum to the right of midline between the thoracic aorta on the left and the azygos vein on the right (Fig. 3.103). It lies posterior to the diaphragm and the esophagus and anterior to the bodies of the vertebrae. At vertebral level TV, the thoracic duct moves to the left of midline and enters the superior mediastinum. It continues through the superior mediastinum and into the neck.
Anatomy_Gray_463
Anatomy_Gray
At vertebral level TV, the thoracic duct moves to the left of midline and enters the superior mediastinum. It continues through the superior mediastinum and into the neck. After being joined, in most cases, by the left jugular trunk, which drains the left side of the head and neck, and the left subclavian trunk, which drains the left upper limb, the thoracic duct empties into the junction of the left subclavian and left internal jugular veins. The thoracic duct usually receives the contents from: the confluence of lymph trunks in the abdomen, descending thoracic lymph trunks draining the lower six or seven intercostal spaces on both sides, upper intercostal lymph trunks draining the upper left five or six intercostal spaces, ducts from posterior mediastinal nodes, and ducts from posterior diaphragmatic nodes.
Anatomy_Gray. At vertebral level TV, the thoracic duct moves to the left of midline and enters the superior mediastinum. It continues through the superior mediastinum and into the neck. After being joined, in most cases, by the left jugular trunk, which drains the left side of the head and neck, and the left subclavian trunk, which drains the left upper limb, the thoracic duct empties into the junction of the left subclavian and left internal jugular veins. The thoracic duct usually receives the contents from: the confluence of lymph trunks in the abdomen, descending thoracic lymph trunks draining the lower six or seven intercostal spaces on both sides, upper intercostal lymph trunks draining the upper left five or six intercostal spaces, ducts from posterior mediastinal nodes, and ducts from posterior diaphragmatic nodes.
Anatomy_Gray_464
Anatomy_Gray
The sympathetic trunks are an important component of the sympathetic part of the autonomic division of the peripheral nervous system and are usually considered a component of the posterior mediastinum as they pass through the thorax. This portion of the sympathetic trunks consists of two parallel cords punctuated by 11 or 12 ganglia (Fig. 3.104). The ganglia are connected to adjacent thoracic spinal nerves by white and gray rami communicantes and are numbered according to the thoracic spinal nerve with which they are associated. In the superior portion of the posterior mediastinum, the trunks are anterior to the neck of the ribs. Inferiorly, they become more medial in position until they lie on the lateral aspect of the vertebral bodies. The sympathetic trunks leave the thorax by passing posterior to the diaphragm under the medial arcuate ligament or through the crura of the diaphragm. Throughout their course the trunks are covered by parietal pleura. Branches from the ganglia
Anatomy_Gray. The sympathetic trunks are an important component of the sympathetic part of the autonomic division of the peripheral nervous system and are usually considered a component of the posterior mediastinum as they pass through the thorax. This portion of the sympathetic trunks consists of two parallel cords punctuated by 11 or 12 ganglia (Fig. 3.104). The ganglia are connected to adjacent thoracic spinal nerves by white and gray rami communicantes and are numbered according to the thoracic spinal nerve with which they are associated. In the superior portion of the posterior mediastinum, the trunks are anterior to the neck of the ribs. Inferiorly, they become more medial in position until they lie on the lateral aspect of the vertebral bodies. The sympathetic trunks leave the thorax by passing posterior to the diaphragm under the medial arcuate ligament or through the crura of the diaphragm. Throughout their course the trunks are covered by parietal pleura. Branches from the ganglia
Anatomy_Gray_465
Anatomy_Gray
Branches from the ganglia Two types of medial branches are given off by the ganglia: The first type includes branches from the upper five ganglia. The second type includes branches from the lower seven ganglia. The first type, which includes branches from the upper five ganglia, consists mainly of postganglionic sympathetic fibers, which supply the various thoracic viscera. These branches are relatively small, and also contain visceral afferent fibers. The second type, which includes branches from the lower seven ganglia, consists mainly of preganglionic sympathetic fibers, which supply the various abdominal and pelvic viscera. These branches are large, also carry visceral afferent fibers, and form the three thoracic splanchnic nerves referred to as the greater, lesser, and least splanchnic nerves (Fig. 3.104).
Anatomy_Gray. Branches from the ganglia Two types of medial branches are given off by the ganglia: The first type includes branches from the upper five ganglia. The second type includes branches from the lower seven ganglia. The first type, which includes branches from the upper five ganglia, consists mainly of postganglionic sympathetic fibers, which supply the various thoracic viscera. These branches are relatively small, and also contain visceral afferent fibers. The second type, which includes branches from the lower seven ganglia, consists mainly of preganglionic sympathetic fibers, which supply the various abdominal and pelvic viscera. These branches are large, also carry visceral afferent fibers, and form the three thoracic splanchnic nerves referred to as the greater, lesser, and least splanchnic nerves (Fig. 3.104).
Anatomy_Gray_466
Anatomy_Gray
The greater splanchnic nerve on each side usually arises from the fifth to ninth or tenth thoracic ganglia. It descends across the vertebral bodies moving in a medial direction, passes into the abdomen through the crus of the diaphragm, and ends in the celiac ganglion. The lesser splanchnic nerve usually arises from the ninth and tenth, or tenth and eleventh thoracic ganglia. It descends across the vertebral bodies moving in a medial direction, and passes into the abdomen through the crus of the diaphragm to end in the aorticorenal ganglion. The least splanchnic nerve (lowest splanchnic nerve) usually arises from the twelfth thoracic ganglion. It descends and passes into the abdomen through the crus of the diaphragm to end in the renal plexus.
Anatomy_Gray. The greater splanchnic nerve on each side usually arises from the fifth to ninth or tenth thoracic ganglia. It descends across the vertebral bodies moving in a medial direction, passes into the abdomen through the crus of the diaphragm, and ends in the celiac ganglion. The lesser splanchnic nerve usually arises from the ninth and tenth, or tenth and eleventh thoracic ganglia. It descends across the vertebral bodies moving in a medial direction, and passes into the abdomen through the crus of the diaphragm to end in the aorticorenal ganglion. The least splanchnic nerve (lowest splanchnic nerve) usually arises from the twelfth thoracic ganglion. It descends and passes into the abdomen through the crus of the diaphragm to end in the renal plexus.
Anatomy_Gray_467
Anatomy_Gray
The ability to visualize how anatomical structures in the thorax are related to surface features is fundamental to a physical examination. Landmarks on the body’s surface can be used to locate deep structures and to assess function by auscultation and percussion. How to count ribs Knowing how to count ribs is important because different ribs provide palpable landmarks for the positions of deeper structures. To determine the location of specific ribs, palpate the jugular notch at the superior extent of the manubrium of the sternum. Move down the sternum until a ridge is felt. This ridge is the sternal angle, which identifies the articulation between the manubrium of the sternum and the body of the sternum. The costal cartilage of rib II articulates with the sternum at this location. Identify rib II. Then continue counting the ribs, moving in a downward and lateral direction (Fig. 3.105). Surface anatomy of the breast in women
Anatomy_Gray. The ability to visualize how anatomical structures in the thorax are related to surface features is fundamental to a physical examination. Landmarks on the body’s surface can be used to locate deep structures and to assess function by auscultation and percussion. How to count ribs Knowing how to count ribs is important because different ribs provide palpable landmarks for the positions of deeper structures. To determine the location of specific ribs, palpate the jugular notch at the superior extent of the manubrium of the sternum. Move down the sternum until a ridge is felt. This ridge is the sternal angle, which identifies the articulation between the manubrium of the sternum and the body of the sternum. The costal cartilage of rib II articulates with the sternum at this location. Identify rib II. Then continue counting the ribs, moving in a downward and lateral direction (Fig. 3.105). Surface anatomy of the breast in women
Anatomy_Gray_468
Anatomy_Gray
Surface anatomy of the breast in women Although breasts vary in size, they are normally positioned on the thoracic wall between ribs II and VI and overlie the pectoralis major muscles. Each mammary gland extends superolaterally around the lower margin of the pectoralis major muscle and enters the axilla (Fig. 3.106). This portion of the gland is the axillary tail or axillary process. The positions of the nipple and areola vary relative to the chest wall depending on breast size. Visualizing structures at the TIV/V The TIV/V vertebral level is a transverse plane that passes through the sternal angle on the anterior chest wall and the intervertebral disc between TIV and TV vertebrae posteriorly. This plane can easily be located, because the joint between the manubrium of the sternum and the body of the sternum forms a distinct bony protuberance that can be palpated. At the TIV/V level (Fig. 3.107): The costal cartilage of rib II articulates with the sternum.
Anatomy_Gray. Surface anatomy of the breast in women Although breasts vary in size, they are normally positioned on the thoracic wall between ribs II and VI and overlie the pectoralis major muscles. Each mammary gland extends superolaterally around the lower margin of the pectoralis major muscle and enters the axilla (Fig. 3.106). This portion of the gland is the axillary tail or axillary process. The positions of the nipple and areola vary relative to the chest wall depending on breast size. Visualizing structures at the TIV/V The TIV/V vertebral level is a transverse plane that passes through the sternal angle on the anterior chest wall and the intervertebral disc between TIV and TV vertebrae posteriorly. This plane can easily be located, because the joint between the manubrium of the sternum and the body of the sternum forms a distinct bony protuberance that can be palpated. At the TIV/V level (Fig. 3.107): The costal cartilage of rib II articulates with the sternum.
Anatomy_Gray_469
Anatomy_Gray
The costal cartilage of rib II articulates with the sternum. The superior mediastinum is separated from the inferior mediastinum. The ascending aorta ends and the arch of the aorta begins. The arch of the aorta ends and the thoracic aorta begins. The trachea bifurcates. Visualizing structures in the superior mediastinum A number of structures in the superior mediastinum in adults can be visualized based on their positions relative to skeletal landmarks that can be palpated through the skin (Fig. 3.108). On each side, the internal jugular and subclavian veins join to form the brachiocephalic veins behind the sternal ends of the clavicles near the sternoclavicular joints. The left brachiocephalic vein crosses from left to right behind the manubrium of the sternum. The brachiocephalic veins unite to form the superior vena cava behind the lower border of the costal cartilage of the right first rib.
Anatomy_Gray. The costal cartilage of rib II articulates with the sternum. The superior mediastinum is separated from the inferior mediastinum. The ascending aorta ends and the arch of the aorta begins. The arch of the aorta ends and the thoracic aorta begins. The trachea bifurcates. Visualizing structures in the superior mediastinum A number of structures in the superior mediastinum in adults can be visualized based on their positions relative to skeletal landmarks that can be palpated through the skin (Fig. 3.108). On each side, the internal jugular and subclavian veins join to form the brachiocephalic veins behind the sternal ends of the clavicles near the sternoclavicular joints. The left brachiocephalic vein crosses from left to right behind the manubrium of the sternum. The brachiocephalic veins unite to form the superior vena cava behind the lower border of the costal cartilage of the right first rib.
Anatomy_Gray_470
Anatomy_Gray
The brachiocephalic veins unite to form the superior vena cava behind the lower border of the costal cartilage of the right first rib. The arch of the aorta begins and ends at the transverse plane between the sternal angle anteriorly and vertebral level TIV/V posteriorly. The arch may reach as high as the midlevel of the manubrium of the sternum. Visualizing the margins of the heart Surface landmarks can be palpated to visualize the outline of the heart (Fig. 3.109). The upper limit of the heart reaches as high as the third costal cartilage on the right side of the sternum and the second intercostal space on the left side of the sternum. The right margin of the heart extends from the right third costal cartilage to near the right sixth costal cartilage. The left margin of the heart descends laterally from the second intercostal space to the apex located near the midclavicular line in the fifth intercostal space.
Anatomy_Gray. The brachiocephalic veins unite to form the superior vena cava behind the lower border of the costal cartilage of the right first rib. The arch of the aorta begins and ends at the transverse plane between the sternal angle anteriorly and vertebral level TIV/V posteriorly. The arch may reach as high as the midlevel of the manubrium of the sternum. Visualizing the margins of the heart Surface landmarks can be palpated to visualize the outline of the heart (Fig. 3.109). The upper limit of the heart reaches as high as the third costal cartilage on the right side of the sternum and the second intercostal space on the left side of the sternum. The right margin of the heart extends from the right third costal cartilage to near the right sixth costal cartilage. The left margin of the heart descends laterally from the second intercostal space to the apex located near the midclavicular line in the fifth intercostal space.
Anatomy_Gray_471
Anatomy_Gray
The left margin of the heart descends laterally from the second intercostal space to the apex located near the midclavicular line in the fifth intercostal space. The lower margin of the heart extends from the sternal end of the right sixth costal cartilage to the apex in the fifth intercostal space near the midclavicular line. Where to listen for heart sounds To listen for valve sounds, position the stethoscope downstream from the flow of blood through the valves (Fig. 3.110). The tricuspid valve is heard just to the left of the lower part of the sternum near the fifth intercostal space. The mitral valve is heard over the apex of the heart in the left fifth intercostal space at the midclavicular line. The pulmonary valve is heard over the medial end of the left second intercostal space. The aortic valve is heard over the medial end of the right second intercostal space. Visualizing the pleural cavities and lungs, pleural recesses, and lung lobes and fissures
Anatomy_Gray. The left margin of the heart descends laterally from the second intercostal space to the apex located near the midclavicular line in the fifth intercostal space. The lower margin of the heart extends from the sternal end of the right sixth costal cartilage to the apex in the fifth intercostal space near the midclavicular line. Where to listen for heart sounds To listen for valve sounds, position the stethoscope downstream from the flow of blood through the valves (Fig. 3.110). The tricuspid valve is heard just to the left of the lower part of the sternum near the fifth intercostal space. The mitral valve is heard over the apex of the heart in the left fifth intercostal space at the midclavicular line. The pulmonary valve is heard over the medial end of the left second intercostal space. The aortic valve is heard over the medial end of the right second intercostal space. Visualizing the pleural cavities and lungs, pleural recesses, and lung lobes and fissures
Anatomy_Gray_472
Anatomy_Gray
The aortic valve is heard over the medial end of the right second intercostal space. Visualizing the pleural cavities and lungs, pleural recesses, and lung lobes and fissures Palpable surface landmarks can be used to visualize the normal outlines of the pleural cavities and the lungs and to determine the positions of the pulmonary lobes and fissures. Superiorly, the parietal pleura projects above the first costal cartilage. Anteriorly, the costal pleura approaches the midline posterior to the upper portion of the sternum. Posterior to the lower portion of the sternum, the left parietal pleura does not come as close to the midline as it does on the right side. This is because the heart bulges onto the left side (Fig. 3.111A). Inferiorly, the pleura reflects onto the diaphragm above the costal margin and courses around the thoracic wall following an VIII, X, XII contour (i.e., rib VIII in the midclavicular line, rib X in the midaxillary line, and vertebra TXII posteriorly).
Anatomy_Gray. The aortic valve is heard over the medial end of the right second intercostal space. Visualizing the pleural cavities and lungs, pleural recesses, and lung lobes and fissures Palpable surface landmarks can be used to visualize the normal outlines of the pleural cavities and the lungs and to determine the positions of the pulmonary lobes and fissures. Superiorly, the parietal pleura projects above the first costal cartilage. Anteriorly, the costal pleura approaches the midline posterior to the upper portion of the sternum. Posterior to the lower portion of the sternum, the left parietal pleura does not come as close to the midline as it does on the right side. This is because the heart bulges onto the left side (Fig. 3.111A). Inferiorly, the pleura reflects onto the diaphragm above the costal margin and courses around the thoracic wall following an VIII, X, XII contour (i.e., rib VIII in the midclavicular line, rib X in the midaxillary line, and vertebra TXII posteriorly).
Anatomy_Gray_473
Anatomy_Gray
The lungs do not completely fill the area surrounded by the pleural cavities, particularly anteriorly and inferiorly. Costomediastinal recesses occur anteriorly, particularly on the left side in relationship to the heart bulge. Costodiaphragmatic recesses occur inferiorly between the lower lung margin and the lower margin of the pleural cavity. In quiet respiration, the inferior margin of the lungs travels around the thoracic wall following a VI, VIII, X contour (i.e., rib VI in the midclavicular line, rib VIII in the midaxillary line, and vertebra TX posteriorly). In the posterior view, the oblique fissure on both sides is located in the midline near the spine of vertebra TIV (Figs. 3.111B and 3.112A). It moves laterally in a downward direction, crossing the fourth and fifth intercostal spaces and reaches rib VI laterally.
Anatomy_Gray. The lungs do not completely fill the area surrounded by the pleural cavities, particularly anteriorly and inferiorly. Costomediastinal recesses occur anteriorly, particularly on the left side in relationship to the heart bulge. Costodiaphragmatic recesses occur inferiorly between the lower lung margin and the lower margin of the pleural cavity. In quiet respiration, the inferior margin of the lungs travels around the thoracic wall following a VI, VIII, X contour (i.e., rib VI in the midclavicular line, rib VIII in the midaxillary line, and vertebra TX posteriorly). In the posterior view, the oblique fissure on both sides is located in the midline near the spine of vertebra TIV (Figs. 3.111B and 3.112A). It moves laterally in a downward direction, crossing the fourth and fifth intercostal spaces and reaches rib VI laterally.
Anatomy_Gray_474
Anatomy_Gray
In the anterior view, the horizontal fissure on the right side follows the contour of rib IV and its costal cartilage and the oblique fissures on both sides follow the contour of rib VI and its costal cartilage (Fig. 3.112B). Where to listen for lung sounds The stethoscope placements for listening for lung sounds are shown in Fig. 3.113. Fig. 3.1 Thoracic wall and cavity. Left pleural cavitySternal angleManubrium of sternumXiphoid processInferior thoracic apertureSuperior thoracic apertureBody of sternumRight pleural cavityDiaphragmVertebral columnRib IRibsMediastinum Fig. 3.2 Joints between ribs and vertebrae. Fig. 3.3 Superior thoracic aperture. Manubriumof sternumEsophagusCommon carotid arteryInternal jugular veinRib ISuperior thoracicapertureApex of right lungSubclavianarteryand veinTracheaVertebra TIRib IITracheaPleauralcavity (lung)VeinsNervesArteriesEsophagus Fig. 3.4 A. Inferior thoracic aperture. B. Diaphragm.
Anatomy_Gray. In the anterior view, the horizontal fissure on the right side follows the contour of rib IV and its costal cartilage and the oblique fissures on both sides follow the contour of rib VI and its costal cartilage (Fig. 3.112B). Where to listen for lung sounds The stethoscope placements for listening for lung sounds are shown in Fig. 3.113. Fig. 3.1 Thoracic wall and cavity. Left pleural cavitySternal angleManubrium of sternumXiphoid processInferior thoracic apertureSuperior thoracic apertureBody of sternumRight pleural cavityDiaphragmVertebral columnRib IRibsMediastinum Fig. 3.2 Joints between ribs and vertebrae. Fig. 3.3 Superior thoracic aperture. Manubriumof sternumEsophagusCommon carotid arteryInternal jugular veinRib ISuperior thoracicapertureApex of right lungSubclavianarteryand veinTracheaVertebra TIRib IITracheaPleauralcavity (lung)VeinsNervesArteriesEsophagus Fig. 3.4 A. Inferior thoracic aperture. B. Diaphragm.
Anatomy_Gray_475
Anatomy_Gray
Fig. 3.4 A. Inferior thoracic aperture. B. Diaphragm. Rib XIDistal cartilaginousends of ribs VII to X;costal marginsCentraltendonLeft domeRight domeAortichiatusEsophagealhiatusInferior thoracicapertureXiphoid processRib XIIVertebra TXIIAB Fig. 3.5 Subdivisions of the mediastinum. Fig. 3.6 Pleural cavities. TracheaLeft pleural cavitysurrounding left lungApex of right lungMediastinumRight main bronchusRight pleural cavityParietal pleuraVisceral pleuraCostodiaphragmaticrecessDiaphragm Fig. 3.7 Superior thoracic aperture and axillary inlet. Fig. 3.8 Major structures passing between abdomen and thorax. Fig. 3.9 Right breast. Fourth thoracicintercostal nerveMammary glandsLactiferousductsLactiferoussinusesPectoralis majorDeep (pectoral) fasciaAxillary processAxillarylymph nodesSecond, third, and fourth anteriorperforating branches of internalthoracic arteryInternalthoracic arteryParasternallymph nodesLymphatic vessel Fig. 3.10 Vertebral level TIV/V.
Anatomy_Gray. Fig. 3.4 A. Inferior thoracic aperture. B. Diaphragm. Rib XIDistal cartilaginousends of ribs VII to X;costal marginsCentraltendonLeft domeRight domeAortichiatusEsophagealhiatusInferior thoracicapertureXiphoid processRib XIIVertebra TXIIAB Fig. 3.5 Subdivisions of the mediastinum. Fig. 3.6 Pleural cavities. TracheaLeft pleural cavitysurrounding left lungApex of right lungMediastinumRight main bronchusRight pleural cavityParietal pleuraVisceral pleuraCostodiaphragmaticrecessDiaphragm Fig. 3.7 Superior thoracic aperture and axillary inlet. Fig. 3.8 Major structures passing between abdomen and thorax. Fig. 3.9 Right breast. Fourth thoracicintercostal nerveMammary glandsLactiferousductsLactiferoussinusesPectoralis majorDeep (pectoral) fasciaAxillary processAxillarylymph nodesSecond, third, and fourth anteriorperforating branches of internalthoracic arteryInternalthoracic arteryParasternallymph nodesLymphatic vessel Fig. 3.10 Vertebral level TIV/V.
Anatomy_Gray_476
Anatomy_Gray
Fig. 3.10 Vertebral level TIV/V. Fig. 3.11 Left-to-right venous shunts. Fig. 3.12 A. Segmental neurovascular supply of thoracic wall. B. Anterior view of thoracic dermatomes associated with thoracic spinal nerves. C. Lateral view of dermatomes associated with thoracic spinal nerves. Left common carotid arteryInternal thoracic arteriesRight subclavian arteryArch of aortaAnteriorcutaneous branchAnteriorintercostal arteryAPosteriorintercostal arteryLateralcutaneous branchIntercostal nerve Fig. 3.13 Sympathetic trunks. Fig. 3.14 Flexible thoracic wall and inferior thoracic aperture. Sternum moves forwardin inspiration because ofrib elevationElevation of lateral aspectof ribs in inspirationDiaphragm descends toincrease thoracic capacityin inspiration Fig. 3.15 Innervation of the diaphragm. Fig. 3.16 Breasts.
Anatomy_Gray. Fig. 3.10 Vertebral level TIV/V. Fig. 3.11 Left-to-right venous shunts. Fig. 3.12 A. Segmental neurovascular supply of thoracic wall. B. Anterior view of thoracic dermatomes associated with thoracic spinal nerves. C. Lateral view of dermatomes associated with thoracic spinal nerves. Left common carotid arteryInternal thoracic arteriesRight subclavian arteryArch of aortaAnteriorcutaneous branchAnteriorintercostal arteryAPosteriorintercostal arteryLateralcutaneous branchIntercostal nerve Fig. 3.13 Sympathetic trunks. Fig. 3.14 Flexible thoracic wall and inferior thoracic aperture. Sternum moves forwardin inspiration because ofrib elevationElevation of lateral aspectof ribs in inspirationDiaphragm descends toincrease thoracic capacityin inspiration Fig. 3.15 Innervation of the diaphragm. Fig. 3.16 Breasts.
Anatomy_Gray_477
Anatomy_Gray
Fig. 3.15 Innervation of the diaphragm. Fig. 3.16 Breasts. Parasternal nodesSuspensory ligamentsLactiferous sinusesLactiferous ductsRetromammary spaceSecretory lobulesPectoralis major muscleMammary branches ofinternal thoracic arteryAxillary processLateral thoracic arteryLateral axillary nodesCentral axillary nodesApical axillary nodesPectoral branch ofthoracoacromial arteryInternal thoracic arteryAreolaSecretorylobulesLymphatic and venous drainagepasses from lateral and superiorpart of the breast into axillaLymphatic and venousdrainage passes from medial partof the breast parasternallySome lymphatic and venous drainagemay pass from inferior part of thebreast into the abdomenPectoral axillary nodes Fig. 3.17 Muscles and fascia of the pectoral region. Fig. 3.18 Typical thoracic vertebra.
Anatomy_Gray. Fig. 3.15 Innervation of the diaphragm. Fig. 3.16 Breasts. Parasternal nodesSuspensory ligamentsLactiferous sinusesLactiferous ductsRetromammary spaceSecretory lobulesPectoralis major muscleMammary branches ofinternal thoracic arteryAxillary processLateral thoracic arteryLateral axillary nodesCentral axillary nodesApical axillary nodesPectoral branch ofthoracoacromial arteryInternal thoracic arteryAreolaSecretorylobulesLymphatic and venous drainagepasses from lateral and superiorpart of the breast into axillaLymphatic and venousdrainage passes from medial partof the breast parasternallySome lymphatic and venous drainagemay pass from inferior part of thebreast into the abdomenPectoral axillary nodes Fig. 3.17 Muscles and fascia of the pectoral region. Fig. 3.18 Typical thoracic vertebra.
Anatomy_Gray_478
Anatomy_Gray
Fig. 3.17 Muscles and fascia of the pectoral region. Fig. 3.18 Typical thoracic vertebra. LaminaSpinous processTransverse processPedicleVertebral bodyPosteriorAnteriorVertebral foramenSuperior demifacetFacet for articulation with tubercle of ribSuperiorPosteriorInferiorAnteriorFacet for articulationwith tubercle of ribDemifacets for articulation with head of ribsSuperior articular processInferior articular processSuperior viewSuperolateral view Fig. 3.19 Atypical thoracic vertebrae. Vertebra TIVertebra TXVertebra TXISuperior costal facet for head of rib ISingle complete costal facet for head of rib XNo costal facet on transverse process Fig. 3.20 Ribs. Fig. 3.21 A typical rib. A. Anterior view. B. Posterior view of proximal end of rib. Fig. 3.22 Atypical ribs. Fig. 3.23 Sternum. Fig. 3.24 Costovertebral joints.
Anatomy_Gray. Fig. 3.17 Muscles and fascia of the pectoral region. Fig. 3.18 Typical thoracic vertebra. LaminaSpinous processTransverse processPedicleVertebral bodyPosteriorAnteriorVertebral foramenSuperior demifacetFacet for articulation with tubercle of ribSuperiorPosteriorInferiorAnteriorFacet for articulationwith tubercle of ribDemifacets for articulation with head of ribsSuperior articular processInferior articular processSuperior viewSuperolateral view Fig. 3.19 Atypical thoracic vertebrae. Vertebra TIVertebra TXVertebra TXISuperior costal facet for head of rib ISingle complete costal facet for head of rib XNo costal facet on transverse process Fig. 3.20 Ribs. Fig. 3.21 A typical rib. A. Anterior view. B. Posterior view of proximal end of rib. Fig. 3.22 Atypical ribs. Fig. 3.23 Sternum. Fig. 3.24 Costovertebral joints.
Anatomy_Gray_479
Anatomy_Gray
Fig. 3.20 Ribs. Fig. 3.21 A typical rib. A. Anterior view. B. Posterior view of proximal end of rib. Fig. 3.22 Atypical ribs. Fig. 3.23 Sternum. Fig. 3.24 Costovertebral joints. Joint capsuleVertebraVertebraDiscRibJoint cavitiesCostotransverse jointCostotransverse ligamentSuperior costotransverse ligamentLateral costotransverseligamentJoint with vertebral bodyIntra-articular ligamentSuperolateral viewSuperior view Fig. 3.25 Sternocostal joints. Fig. 3.26 Intercostal space. A. Anterolateral view. B. Details of an intercostal space and relationships. Intercostal space. C. Transverse section.
Anatomy_Gray. Fig. 3.20 Ribs. Fig. 3.21 A typical rib. A. Anterior view. B. Posterior view of proximal end of rib. Fig. 3.22 Atypical ribs. Fig. 3.23 Sternum. Fig. 3.24 Costovertebral joints. Joint capsuleVertebraVertebraDiscRibJoint cavitiesCostotransverse jointCostotransverse ligamentSuperior costotransverse ligamentLateral costotransverseligamentJoint with vertebral bodyIntra-articular ligamentSuperolateral viewSuperior view Fig. 3.25 Sternocostal joints. Fig. 3.26 Intercostal space. A. Anterolateral view. B. Details of an intercostal space and relationships. Intercostal space. C. Transverse section.
Anatomy_Gray_480
Anatomy_Gray
Fig. 3.25 Sternocostal joints. Fig. 3.26 Intercostal space. A. Anterolateral view. B. Details of an intercostal space and relationships. Intercostal space. C. Transverse section. Posterior ramus of spinal nerveLateral branches ofintercostal nerveand vesselsAnterior cutaneousbranch ofintercostal nerve Anterior perforatingbranches ofintercostal vessels Intercostal nerveCostal grooveAortaInternal thoracic arteryand veinPosterior intercostal artery and veinAnterior intercostal artery and veinCollateral branches ofintercostal nerve and vesselsIntercostal veinIntercostal arteryVisceral pleuraParietal pleuraEndothoracic fasciaPleural cavityLungIntercostal nerveCollateral branchesInternal intercostal muscleExternal intercostal muscleSerratus anterior muscleInnermost intercostal muscleSuperficial fasciaSkinAB Fig. 3.27 Intercostal muscles. Fig. 3.28 A. Subcostal muscles. B. Transversus thoracis muscles. Fig. 3.29 Arteries of the thoracic wall.
Anatomy_Gray. Fig. 3.25 Sternocostal joints. Fig. 3.26 Intercostal space. A. Anterolateral view. B. Details of an intercostal space and relationships. Intercostal space. C. Transverse section. Posterior ramus of spinal nerveLateral branches ofintercostal nerveand vesselsAnterior cutaneousbranch ofintercostal nerve Anterior perforatingbranches ofintercostal vessels Intercostal nerveCostal grooveAortaInternal thoracic arteryand veinPosterior intercostal artery and veinAnterior intercostal artery and veinCollateral branches ofintercostal nerve and vesselsIntercostal veinIntercostal arteryVisceral pleuraParietal pleuraEndothoracic fasciaPleural cavityLungIntercostal nerveCollateral branchesInternal intercostal muscleExternal intercostal muscleSerratus anterior muscleInnermost intercostal muscleSuperficial fasciaSkinAB Fig. 3.27 Intercostal muscles. Fig. 3.28 A. Subcostal muscles. B. Transversus thoracis muscles. Fig. 3.29 Arteries of the thoracic wall.
Anatomy_Gray_481
Anatomy_Gray
Fig. 3.27 Intercostal muscles. Fig. 3.28 A. Subcostal muscles. B. Transversus thoracis muscles. Fig. 3.29 Arteries of the thoracic wall. Superior epigastric arteryInternal thoracic arteryAortaAnterior perforatingbranchesAnterior intercostal arteryCollateral branch of posteriorintercostal arterySupreme intercostal arteryPosterior intercostal arteryMusculophrenic arterySubclavian arteryCostocervical trunk Fig. 3.30 Veins of the thoracic wall. Fig. 3.31 Major lymphatic vessels and nodes of the thoracic wall. Fig. 3.32 Intercostal nerves. Fig. 3.33 Right thoracotomy for esophageal cancer with intrathoracic large-bore drain. In this case, a neo-esophagus has been fashioned from the stomach. Fig. 3.34 Diaphragm. Fig. 3.35 Movement of thoracic wall during breathing. A. Pump handle movement of ribs and sternum. B. Bucket handle movement of ribs. BuckethandlemovementElevation of lateralshaft of ribSuperior and anteriormovement of sternumBAPump handle
Anatomy_Gray. Fig. 3.27 Intercostal muscles. Fig. 3.28 A. Subcostal muscles. B. Transversus thoracis muscles. Fig. 3.29 Arteries of the thoracic wall. Superior epigastric arteryInternal thoracic arteryAortaAnterior perforatingbranchesAnterior intercostal arteryCollateral branch of posteriorintercostal arterySupreme intercostal arteryPosterior intercostal arteryMusculophrenic arterySubclavian arteryCostocervical trunk Fig. 3.30 Veins of the thoracic wall. Fig. 3.31 Major lymphatic vessels and nodes of the thoracic wall. Fig. 3.32 Intercostal nerves. Fig. 3.33 Right thoracotomy for esophageal cancer with intrathoracic large-bore drain. In this case, a neo-esophagus has been fashioned from the stomach. Fig. 3.34 Diaphragm. Fig. 3.35 Movement of thoracic wall during breathing. A. Pump handle movement of ribs and sternum. B. Bucket handle movement of ribs. BuckethandlemovementElevation of lateralshaft of ribSuperior and anteriormovement of sternumBAPump handle
Anatomy_Gray_482
Anatomy_Gray
BuckethandlemovementElevation of lateralshaft of ribSuperior and anteriormovement of sternumBAPump handle Fig. 3.36 Chest radiograph showing an elevated right hemidiaphragm in a patient with right-sided diaphragmatic paralysis. Fig. 3.37 Pleural cavities. Fig. 3.38 Parietal pleura. Costal partPulmonary ligamentMediastinal partPleura surroundingstructures in root of lungCervical pleuraSuprapleural membraneDiaphragmatic part Fig. 3.39 Pleural reflections. Fig. 3.40 Parietal pleural reflections and recesses. Fig. 3.41 CT image of left pleural effusion. AortaLeft lungRight lungLeft empyema with air-fluid level Fig. 3.42 Pneumothorax in a patient with extensive subcutaneous emphysema. Fig. 3.43 Lungs. Fig. 3.44 Roots and hila of the lungs. Fig. 3.45 A. Right lung. B. Major structures related to the right lung.
Anatomy_Gray. BuckethandlemovementElevation of lateralshaft of ribSuperior and anteriormovement of sternumBAPump handle Fig. 3.36 Chest radiograph showing an elevated right hemidiaphragm in a patient with right-sided diaphragmatic paralysis. Fig. 3.37 Pleural cavities. Fig. 3.38 Parietal pleura. Costal partPulmonary ligamentMediastinal partPleura surroundingstructures in root of lungCervical pleuraSuprapleural membraneDiaphragmatic part Fig. 3.39 Pleural reflections. Fig. 3.40 Parietal pleural reflections and recesses. Fig. 3.41 CT image of left pleural effusion. AortaLeft lungRight lungLeft empyema with air-fluid level Fig. 3.42 Pneumothorax in a patient with extensive subcutaneous emphysema. Fig. 3.43 Lungs. Fig. 3.44 Roots and hila of the lungs. Fig. 3.45 A. Right lung. B. Major structures related to the right lung.
Anatomy_Gray_483
Anatomy_Gray
Fig. 3.43 Lungs. Fig. 3.44 Roots and hila of the lungs. Fig. 3.45 A. Right lung. B. Major structures related to the right lung. DiaphragmBronchusBronchus to superior lobePulmonary arteryPulmonary veinsRib ISubclavian arterySubclavian veinEsophagusPosteriorAnteriorInferior vena cavaAzygos veinLeft brachiocephalic veinRight brachiocephalic veinHeartInferior lobeSuperior lobeMiddle lobeSuperior vena cavaOblique fissureHorizontal fissureAB Fig. 3.46 A. Left lung. B. Major structures related to the left lung. Fig. 3.47 A. Bronchial tree. B. Bronchopulmonary segments. TracheaLeft main bronchusCarinaRight main bronchusLobar bronchiLobar bronchiSegmental bronchiof middle lobeBranch of pulmonary arteryMedial bronchopulmonary segmentof middle lobe of right lungLateral bronchopulmonary segmentof middle lobe of right lungAB Fig. 3.48 Bronchopulmonary segments. A. Right lung. B. Left lung. (Bronchopulmonary segments are numbered and named.)
Anatomy_Gray. Fig. 3.43 Lungs. Fig. 3.44 Roots and hila of the lungs. Fig. 3.45 A. Right lung. B. Major structures related to the right lung. DiaphragmBronchusBronchus to superior lobePulmonary arteryPulmonary veinsRib ISubclavian arterySubclavian veinEsophagusPosteriorAnteriorInferior vena cavaAzygos veinLeft brachiocephalic veinRight brachiocephalic veinHeartInferior lobeSuperior lobeMiddle lobeSuperior vena cavaOblique fissureHorizontal fissureAB Fig. 3.46 A. Left lung. B. Major structures related to the left lung. Fig. 3.47 A. Bronchial tree. B. Bronchopulmonary segments. TracheaLeft main bronchusCarinaRight main bronchusLobar bronchiLobar bronchiSegmental bronchiof middle lobeBranch of pulmonary arteryMedial bronchopulmonary segmentof middle lobe of right lungLateral bronchopulmonary segmentof middle lobe of right lungAB Fig. 3.48 Bronchopulmonary segments. A. Right lung. B. Left lung. (Bronchopulmonary segments are numbered and named.)
Anatomy_Gray_484
Anatomy_Gray
Fig. 3.48 Bronchopulmonary segments. A. Right lung. B. Left lung. (Bronchopulmonary segments are numbered and named.) Fig. 3.49 Pulmonary vessels. A. Diagram of an anterior view. B. Axial computed tomography image showing the left pulmonary artery branching from the pulmonary trunk. C. Axial computed tomography image (just inferior to the image in B) showing the right pulmonary artery branching from the pulmonary trunk. Fig. 3.50 Pulmonary innervation. Fig. 3.51 Lymphatic drainage of lungs. Fig. 3.52 HRCT of patient with emphysema. Fig. 3.53 Bronchoscopic evaluation. A. Of the lower end of the trachea and its main branches. B. Of tracheal bifurcation showing a tumor at the carina.
Anatomy_Gray. Fig. 3.48 Bronchopulmonary segments. A. Right lung. B. Left lung. (Bronchopulmonary segments are numbered and named.) Fig. 3.49 Pulmonary vessels. A. Diagram of an anterior view. B. Axial computed tomography image showing the left pulmonary artery branching from the pulmonary trunk. C. Axial computed tomography image (just inferior to the image in B) showing the right pulmonary artery branching from the pulmonary trunk. Fig. 3.50 Pulmonary innervation. Fig. 3.51 Lymphatic drainage of lungs. Fig. 3.52 HRCT of patient with emphysema. Fig. 3.53 Bronchoscopic evaluation. A. Of the lower end of the trachea and its main branches. B. Of tracheal bifurcation showing a tumor at the carina.
Anatomy_Gray_485
Anatomy_Gray
Fig. 3.52 HRCT of patient with emphysema. Fig. 3.53 Bronchoscopic evaluation. A. Of the lower end of the trachea and its main branches. B. Of tracheal bifurcation showing a tumor at the carina. Fig. 3.54 Imaging of the lungs. A. Standard posteroanterior view of the chest showing tumor in upper right lung. B. Axial CT image of lungs showing tumor in right lung. C. Coronal CT image of lungs showing tumor in left lung extending into mediastinum. D. Radionuclide study using FDG PET showing a tumor in the right lung. Fig. 3.55 Cross-section of the thorax showing the position of the mediastinum. Fig. 3.56 Lateral view of the mediastinum. Fig. 3.57 Subdivisions of the mediastinum. Fig. 3.58 Thymus. Fig. 3.59 Sagittal section of the pericardium. FibrouspericardiumParietal layerof serouspericardiumVisceral layerof serouspericardium(epicardium)PericardialcavityJunction between fibrous pericardium and adventitia of great vessels Fig. 3.60 Phrenic nerves and pericardiacophrenic vessels.
Anatomy_Gray. Fig. 3.52 HRCT of patient with emphysema. Fig. 3.53 Bronchoscopic evaluation. A. Of the lower end of the trachea and its main branches. B. Of tracheal bifurcation showing a tumor at the carina. Fig. 3.54 Imaging of the lungs. A. Standard posteroanterior view of the chest showing tumor in upper right lung. B. Axial CT image of lungs showing tumor in right lung. C. Coronal CT image of lungs showing tumor in left lung extending into mediastinum. D. Radionuclide study using FDG PET showing a tumor in the right lung. Fig. 3.55 Cross-section of the thorax showing the position of the mediastinum. Fig. 3.56 Lateral view of the mediastinum. Fig. 3.57 Subdivisions of the mediastinum. Fig. 3.58 Thymus. Fig. 3.59 Sagittal section of the pericardium. FibrouspericardiumParietal layerof serouspericardiumVisceral layerof serouspericardium(epicardium)PericardialcavityJunction between fibrous pericardium and adventitia of great vessels Fig. 3.60 Phrenic nerves and pericardiacophrenic vessels.
Anatomy_Gray_486
Anatomy_Gray
Fig. 3.60 Phrenic nerves and pericardiacophrenic vessels. Fig. 3.61 Posterior portion of pericardial sac showing reflections of serous pericardium. Arch of aortaSuperior vena cavaInferior vena cavaBranch of rightpulmonary arteryAscending aortaThoracic aortaCut edge of pericardiumRight pulmonary veinsLeft pulmonary arteryLeft pulmonary veinsOblique pericardial sinus(formed by reflection onto thepulmonary veins of heart)Transverse pericardial sinus(separates arteries from veins) Fig. 3.62 Coronal CT showing pericardial effusion. Fig. 3.63 Schematic illustration of the heart showing orientation, surfaces, and margins. Fig. 3.64 Base of the heart. Arch of aortaSuperior vena cavaInferior vena cavaRight pulmonary arterySulcus terminalisRight pulmonary veinsRight atriumRight ventricleApexLeft atriumLeft inferior pulmonary veinLeft superior pulmonary veinLeft ventricleCoronary sinusLeft pulmonary artery Fig. 3.65 Anterior surface of the heart.
Anatomy_Gray. Fig. 3.60 Phrenic nerves and pericardiacophrenic vessels. Fig. 3.61 Posterior portion of pericardial sac showing reflections of serous pericardium. Arch of aortaSuperior vena cavaInferior vena cavaBranch of rightpulmonary arteryAscending aortaThoracic aortaCut edge of pericardiumRight pulmonary veinsLeft pulmonary arteryLeft pulmonary veinsOblique pericardial sinus(formed by reflection onto thepulmonary veins of heart)Transverse pericardial sinus(separates arteries from veins) Fig. 3.62 Coronal CT showing pericardial effusion. Fig. 3.63 Schematic illustration of the heart showing orientation, surfaces, and margins. Fig. 3.64 Base of the heart. Arch of aortaSuperior vena cavaInferior vena cavaRight pulmonary arterySulcus terminalisRight pulmonary veinsRight atriumRight ventricleApexLeft atriumLeft inferior pulmonary veinLeft superior pulmonary veinLeft ventricleCoronary sinusLeft pulmonary artery Fig. 3.65 Anterior surface of the heart.
Anatomy_Gray_487
Anatomy_Gray
Fig. 3.65 Anterior surface of the heart. RALABicuspidvalveTricuspid valveAortic valvePulmonary trunkPulmonary valveAortaRVLVArch of aortaSuperior vena cavaInferior vena cavaRight coronaryarteryRight atriumRight ventricleAscending aortaInferior marginApexSmall cardiac veinPulmonary trunkLeft auricleLeft ventricleObtuse marginAnterior interventricular grooveGreat cardiac veinAnterior interventricular branch of left coronary artery Fig. 3.66 Diaphragmatic surface of the heart. Arch of aortaSuperior vena cavaInferior vena cavaRight pulmonary arteryRight pulmonary veinsRight atriumRight ventricleMiddle cardiac veinMarginal branch ofright coronary arteryApexLeft atriumLeft pulmonary veinsLeft ventricleCoronary sinusLeft pulmonary arteryPosterior interventricular groovePosterior interventricularbranch of right coronaryartery Fig. 3.67 Chest radiographs. A. Standard posteroanterior view of the chest. B. Standard lateral view of the heart.
Anatomy_Gray. Fig. 3.65 Anterior surface of the heart. RALABicuspidvalveTricuspid valveAortic valvePulmonary trunkPulmonary valveAortaRVLVArch of aortaSuperior vena cavaInferior vena cavaRight coronaryarteryRight atriumRight ventricleAscending aortaInferior marginApexSmall cardiac veinPulmonary trunkLeft auricleLeft ventricleObtuse marginAnterior interventricular grooveGreat cardiac veinAnterior interventricular branch of left coronary artery Fig. 3.66 Diaphragmatic surface of the heart. Arch of aortaSuperior vena cavaInferior vena cavaRight pulmonary arteryRight pulmonary veinsRight atriumRight ventricleMiddle cardiac veinMarginal branch ofright coronary arteryApexLeft atriumLeft pulmonary veinsLeft ventricleCoronary sinusLeft pulmonary arteryPosterior interventricular groovePosterior interventricularbranch of right coronaryartery Fig. 3.67 Chest radiographs. A. Standard posteroanterior view of the chest. B. Standard lateral view of the heart.
Anatomy_Gray_488
Anatomy_Gray
Fig. 3.67 Chest radiographs. A. Standard posteroanterior view of the chest. B. Standard lateral view of the heart. Right ventricleLeft atrium Right atriumArch of aortaInferior vena cavaABPulmonary trunkLeft auricleLeft ventricle Superior vena cava Apex of heart Fig. 3.68 Sulci of the heart. A. Anterior surface of the heart. B. Diaphragmatic surface and base of the heart. Fig. 3.69 A. The heart has two pumps. B. Magnetic resonance image of midthorax showing all four chambers and septa. Fig. 3.70 Internal view of right atrium. Arch of aortaSuperior vena cavaInferior vena cavaLimbus of fossa ovalisCrista terminalisMusculi pectinatiRight ventricleFossa ovalisValve of coronary sinusOpening of coronary sinusRight auricleValve of inferior vena cava Fig. 3.71 Internal view of the right ventricle.
Anatomy_Gray. Fig. 3.67 Chest radiographs. A. Standard posteroanterior view of the chest. B. Standard lateral view of the heart. Right ventricleLeft atrium Right atriumArch of aortaInferior vena cavaABPulmonary trunkLeft auricleLeft ventricle Superior vena cava Apex of heart Fig. 3.68 Sulci of the heart. A. Anterior surface of the heart. B. Diaphragmatic surface and base of the heart. Fig. 3.69 A. The heart has two pumps. B. Magnetic resonance image of midthorax showing all four chambers and septa. Fig. 3.70 Internal view of right atrium. Arch of aortaSuperior vena cavaInferior vena cavaLimbus of fossa ovalisCrista terminalisMusculi pectinatiRight ventricleFossa ovalisValve of coronary sinusOpening of coronary sinusRight auricleValve of inferior vena cava Fig. 3.71 Internal view of the right ventricle.
Anatomy_Gray_489
Anatomy_Gray
Fig. 3.71 Internal view of the right ventricle. Arch of aortaSuperior vena cavaTricuspidvalveRight auricleRight atriumAnterior cuspSeptal cuspPosterior cuspPosterior papillary muscleTrabeculae carneaeAnterior papillary muscleChordae tendineaePulmonary trunkPulmonaryvalveLeft auricleSeptal papillary muscleSeptomarginal trabeculaAnterior semilunar cuspRight semilunar cuspLeft semilunar cuspConus arteriosus Fig. 3.72 Posterior view of the pulmonary valve. Fig. 3.73 Left atrium. A. Internal view. B. Axial computed tomography image showing the pulmonary veins entering the left atrium. Arch of aortaMitral valveLeft auricleABPulmonary arteriesPulmonary veinsValve of foramen ovaleLeft ventricleLeft atriumAscending aortaRight ventricleRight pulmonary veinLeft atriumEsophagusThoracic aortaLeft pulmonary vein Fig. 3.74 Internal view of the left ventricle.
Anatomy_Gray. Fig. 3.71 Internal view of the right ventricle. Arch of aortaSuperior vena cavaTricuspidvalveRight auricleRight atriumAnterior cuspSeptal cuspPosterior cuspPosterior papillary muscleTrabeculae carneaeAnterior papillary muscleChordae tendineaePulmonary trunkPulmonaryvalveLeft auricleSeptal papillary muscleSeptomarginal trabeculaAnterior semilunar cuspRight semilunar cuspLeft semilunar cuspConus arteriosus Fig. 3.72 Posterior view of the pulmonary valve. Fig. 3.73 Left atrium. A. Internal view. B. Axial computed tomography image showing the pulmonary veins entering the left atrium. Arch of aortaMitral valveLeft auricleABPulmonary arteriesPulmonary veinsValve of foramen ovaleLeft ventricleLeft atriumAscending aortaRight ventricleRight pulmonary veinLeft atriumEsophagusThoracic aortaLeft pulmonary vein Fig. 3.74 Internal view of the left ventricle.
Anatomy_Gray_490
Anatomy_Gray
Fig. 3.74 Internal view of the left ventricle. Arch of aortaCoronary sinusMitral valve posterior cuspPulmonary arteriesPulmonary veinsAnterior papillarymuscleMitral valve anterior cuspPosterior papillarymuscleChordae tendineaeTrabeculae carneaeLeft atrium Fig. 3.75 Anterior view of the aortic valve. Fig. 3.76 Cardiac skeleton (atria removed). Right fibrous trigoneLeft fibrous trigoneLeft atrioventricular ringFibrous ring of pulmonary valveAtrioventricular bundleRight atrioventricular ringFibrous ring of aortic valveAntAntAntRtRtPostPostPostPosteriorAnteriorLeftRightSeptalLtLt Fig. 3.77 Cardiac vasculature. A. Anterior view. B. Superior view (atria removed). Fig. 3.78 A. Anterior view of coronary arterial system. Right dominant coronary artery. B. Left anterior oblique view of right coronary artery. C. Right anterior oblique view of left coronary artery.
Anatomy_Gray. Fig. 3.74 Internal view of the left ventricle. Arch of aortaCoronary sinusMitral valve posterior cuspPulmonary arteriesPulmonary veinsAnterior papillarymuscleMitral valve anterior cuspPosterior papillarymuscleChordae tendineaeTrabeculae carneaeLeft atrium Fig. 3.75 Anterior view of the aortic valve. Fig. 3.76 Cardiac skeleton (atria removed). Right fibrous trigoneLeft fibrous trigoneLeft atrioventricular ringFibrous ring of pulmonary valveAtrioventricular bundleRight atrioventricular ringFibrous ring of aortic valveAntAntAntRtRtPostPostPostPosteriorAnteriorLeftRightSeptalLtLt Fig. 3.77 Cardiac vasculature. A. Anterior view. B. Superior view (atria removed). Fig. 3.78 A. Anterior view of coronary arterial system. Right dominant coronary artery. B. Left anterior oblique view of right coronary artery. C. Right anterior oblique view of left coronary artery.
Anatomy_Gray_491
Anatomy_Gray
C. Right anterior oblique view of left coronary artery. Right marginal branch Posterior interventricular branchRight coronary artery Left marginal branch Circumflex branchAnterior interventricular branchRight marginal branchof right coronary artery Right coronary arteryRight atriumRight ventricleSinu-atrial nodal branchof right coronary arteryABCPosterior interventricularbranch of right coronary artery Anterior interventricularbranch of leftcoronary artery Left coronary arteryCircumflex branchof left coronary arteryLeft marginal branchof circumflex branchDiagonal branch ofanterior interventricular branchLeft auricleLeft ventricle Fig. 3.79 Left dominant coronary artery.
Anatomy_Gray. C. Right anterior oblique view of left coronary artery. Right marginal branch Posterior interventricular branchRight coronary artery Left marginal branch Circumflex branchAnterior interventricular branchRight marginal branchof right coronary artery Right coronary arteryRight atriumRight ventricleSinu-atrial nodal branchof right coronary arteryABCPosterior interventricularbranch of right coronary artery Anterior interventricularbranch of leftcoronary artery Left coronary arteryCircumflex branchof left coronary arteryLeft marginal branchof circumflex branchDiagonal branch ofanterior interventricular branchLeft auricleLeft ventricle Fig. 3.79 Left dominant coronary artery.
Anatomy_Gray_492
Anatomy_Gray
Fig. 3.79 Left dominant coronary artery. Right marginal branchof right coronary arteryRight coronary arteryPosterior interventricular branch ofcircumflex branch of left coronary arterySinu-atrial nodal branchof left coronary arteryAnterior interventricularbranch of left coronary artery Left coronary arteryCircumflex branchof left coronary arteryLeft marginal branchof circumflex branchDiagonal branch ofanterior interventricular branch Fig. 3.80 A and B. Axial maximum intensity projection (MIP) CT image through the heart. A. Normal anterior interventricular (left anterior descending) artery. B. Stenotic (calcified) anterior interventricular (left anterior descending) artery. C and D. Vertical long axis multiplanar reformation (MRP) CT image through the heart. C. Normal anterior interventricular (left anterior descending) artery. D. Stenotic (calcified) anterior interventricular (left anterior descending) artery.
Anatomy_Gray. Fig. 3.79 Left dominant coronary artery. Right marginal branchof right coronary arteryRight coronary arteryPosterior interventricular branch ofcircumflex branch of left coronary arterySinu-atrial nodal branchof left coronary arteryAnterior interventricularbranch of left coronary artery Left coronary arteryCircumflex branchof left coronary arteryLeft marginal branchof circumflex branchDiagonal branch ofanterior interventricular branch Fig. 3.80 A and B. Axial maximum intensity projection (MIP) CT image through the heart. A. Normal anterior interventricular (left anterior descending) artery. B. Stenotic (calcified) anterior interventricular (left anterior descending) artery. C and D. Vertical long axis multiplanar reformation (MRP) CT image through the heart. C. Normal anterior interventricular (left anterior descending) artery. D. Stenotic (calcified) anterior interventricular (left anterior descending) artery.
Anatomy_Gray_493
Anatomy_Gray
Fig. 3.81 Heart sounds and how they relate to valve closure, the electrocardiogram (ECG), and ventricular pressure. RPQST1st2nd1stSYSTOLESYSTOLEDIASTOLEVentricularpressureECGHeartsoundsAtrial contractionClosure of mitraland tricuspid valvesClosure of aortic andpulmonary valves"lub""lub""dub" Fig. 3.82 Major cardiac veins. A. Anterior view of major cardiac veins. B. Posteroinferior view of major cardiac veins. Fig. 3.83 Conduction system of the heart. A. Right chambers. B. Left chambers. Fig. 3.84 Cardiac plexus. A. Superficial. B. Deep. Left vagus nerveRight vagus nerveVagal cardiac branchesVagal cardiac branchesCardiac nerves fromsympathetic trunkSuperior vena cavaArch of aortaSuperficial cardiac plexusPulmonary trunkLeft recurrent laryngeal nerveRight recurrent laryngeal nerveLeft vagus nerveRight vagus nerveCardiac nerves from sympathetic trunkDeep cardiac plexusVagal cardiac branchesVagal cardiac branchesAB
Anatomy_Gray. Fig. 3.81 Heart sounds and how they relate to valve closure, the electrocardiogram (ECG), and ventricular pressure. RPQST1st2nd1stSYSTOLESYSTOLEDIASTOLEVentricularpressureECGHeartsoundsAtrial contractionClosure of mitraland tricuspid valvesClosure of aortic andpulmonary valves"lub""lub""dub" Fig. 3.82 Major cardiac veins. A. Anterior view of major cardiac veins. B. Posteroinferior view of major cardiac veins. Fig. 3.83 Conduction system of the heart. A. Right chambers. B. Left chambers. Fig. 3.84 Cardiac plexus. A. Superficial. B. Deep. Left vagus nerveRight vagus nerveVagal cardiac branchesVagal cardiac branchesCardiac nerves fromsympathetic trunkSuperior vena cavaArch of aortaSuperficial cardiac plexusPulmonary trunkLeft recurrent laryngeal nerveRight recurrent laryngeal nerveLeft vagus nerveRight vagus nerveCardiac nerves from sympathetic trunkDeep cardiac plexusVagal cardiac branchesVagal cardiac branchesAB
Anatomy_Gray_494
Anatomy_Gray
Fig. 3.85 Major vessels within the middle mediastinum. A. Anterior view. B. Posterior view. Ascending aortaPulmonary trunkSuperiorvena cavaSuperior vena cavaInferior vena cavaOblique pericardial sinusRight pulmonaryarteryRight pulmonaryveinsRight atriumLeft pulmonaryveinsLeft pulmonaryarteryArch of aortaAB Fig. 3.86 Structures in the superior mediastinum. Right internal jugular veinRight common carotid arteryLeft common carotid arteryLeft subclavian arteryRight subclavian arteryRight pulmonary arteryLeft pulmonary arteryPulmonary trunkLeft subclavian veinLeft brachiocephalic veinRight brachiocephalic veinRight subclavian veinLeft internal jugular veinTracheaEsophagusEsophagusArch of aortaAscending aortaThoracic aortaLeft main bronchusRight main bronchusSuperior vena cava Fig. 3.87 Cross section through the superior mediastinum at the level of vertebra TIII. A. Diagram. B. Axial computed tomography image.
Anatomy_Gray. Fig. 3.85 Major vessels within the middle mediastinum. A. Anterior view. B. Posterior view. Ascending aortaPulmonary trunkSuperiorvena cavaSuperior vena cavaInferior vena cavaOblique pericardial sinusRight pulmonaryarteryRight pulmonaryveinsRight atriumLeft pulmonaryveinsLeft pulmonaryarteryArch of aortaAB Fig. 3.86 Structures in the superior mediastinum. Right internal jugular veinRight common carotid arteryLeft common carotid arteryLeft subclavian arteryRight subclavian arteryRight pulmonary arteryLeft pulmonary arteryPulmonary trunkLeft subclavian veinLeft brachiocephalic veinRight brachiocephalic veinRight subclavian veinLeft internal jugular veinTracheaEsophagusEsophagusArch of aortaAscending aortaThoracic aortaLeft main bronchusRight main bronchusSuperior vena cava Fig. 3.87 Cross section through the superior mediastinum at the level of vertebra TIII. A. Diagram. B. Axial computed tomography image.
Anatomy_Gray_495
Anatomy_Gray
Fig. 3.87 Cross section through the superior mediastinum at the level of vertebra TIII. A. Diagram. B. Axial computed tomography image. ThymusManubrium of sternumLeft brachiocephalic veinRight brachiocephalic veinBrachiocephalic trunkLeft phrenic nerveRight phrenic nerveLeft vagus nerveLeft recurrent laryngeal nerveRight vagus nerveLeft common carotid arteryLeft subclavian arteryThoracic ductEsophagusTIIITracheaABLeft common carotid arteryEsophagusLeft subclavian arteryTracheaLeft brachiocephalic veinBrachiocephalic trunkRight brachiocephalic vein Fig. 3.88 Superior mediastinum with thymus removed. Fig. 3.89 Left superior intercostal vein. Fig. 3.90 Superior mediastinum with thymus and venous channels removed. Fig. 3.91 Axial CT showing aortic dissection. Fig. 3.92 Cross section through the superior mediastinum at the level of vertebra TIV. A. Diagram. B. Axial computed tomography image.
Anatomy_Gray. Fig. 3.87 Cross section through the superior mediastinum at the level of vertebra TIII. A. Diagram. B. Axial computed tomography image. ThymusManubrium of sternumLeft brachiocephalic veinRight brachiocephalic veinBrachiocephalic trunkLeft phrenic nerveRight phrenic nerveLeft vagus nerveLeft recurrent laryngeal nerveRight vagus nerveLeft common carotid arteryLeft subclavian arteryThoracic ductEsophagusTIIITracheaABLeft common carotid arteryEsophagusLeft subclavian arteryTracheaLeft brachiocephalic veinBrachiocephalic trunkRight brachiocephalic vein Fig. 3.88 Superior mediastinum with thymus removed. Fig. 3.89 Left superior intercostal vein. Fig. 3.90 Superior mediastinum with thymus and venous channels removed. Fig. 3.91 Axial CT showing aortic dissection. Fig. 3.92 Cross section through the superior mediastinum at the level of vertebra TIV. A. Diagram. B. Axial computed tomography image.
Anatomy_Gray_496
Anatomy_Gray
Fig. 3.91 Axial CT showing aortic dissection. Fig. 3.92 Cross section through the superior mediastinum at the level of vertebra TIV. A. Diagram. B. Axial computed tomography image. Manubrium of sternumThymusLeft phrenic nerveRight phrenicnerveArch of aortaLeft vagus nerveRight vagusnerveLeft recurrent laryngeal nerveThoracic ductTIVSuperior vena cavaTracheaArch ofazygos veinArch ofazygos veinEsophagusBAEsophagusTracheaArch of aortaSuperior vena cava Fig. 3.93 Trachea in the superior mediastinum. TracheaLeft brachiocephalicveinBrachiocephalictrunkLeft mainbronchusRight main bronchusPulmonary trunkSuperior venacavaArch of aortaTIV/V vertebrallevel Fig. 3.94 Right vagus nerve passing through the superior mediastinum. Fig. 3.95 Left vagus nerve passing through the superior mediastinum. Fig. 3.96 Left recurrent laryngeal nerve passing through the superior mediastinum.
Anatomy_Gray. Fig. 3.91 Axial CT showing aortic dissection. Fig. 3.92 Cross section through the superior mediastinum at the level of vertebra TIV. A. Diagram. B. Axial computed tomography image. Manubrium of sternumThymusLeft phrenic nerveRight phrenicnerveArch of aortaLeft vagus nerveRight vagusnerveLeft recurrent laryngeal nerveThoracic ductTIVSuperior vena cavaTracheaArch ofazygos veinArch ofazygos veinEsophagusBAEsophagusTracheaArch of aortaSuperior vena cava Fig. 3.93 Trachea in the superior mediastinum. TracheaLeft brachiocephalicveinBrachiocephalictrunkLeft mainbronchusRight main bronchusPulmonary trunkSuperior venacavaArch of aortaTIV/V vertebrallevel Fig. 3.94 Right vagus nerve passing through the superior mediastinum. Fig. 3.95 Left vagus nerve passing through the superior mediastinum. Fig. 3.96 Left recurrent laryngeal nerve passing through the superior mediastinum.
Anatomy_Gray_497
Anatomy_Gray
Fig. 3.95 Left vagus nerve passing through the superior mediastinum. Fig. 3.96 Left recurrent laryngeal nerve passing through the superior mediastinum. Left recurrent laryngeal nerveLeft vagus nerveRight mainbronchusTIV/VvertebrallevelLeft main bronchusLigamentum arteriosumLeft pulmonary arteryLeft subclavian arteryPulmonary trunkEsophagusEsophagusTracheaThoracic aortaArch of aorta Fig. 3.97 Esophagus. Right main bronchusLeft main bronchusLeft subclavian arteryLeft common carotid arteryEsophagusEsophagusTracheaThoracic aortaArch of aortaBrachiocephalic trunkDiaphragm Fig. 3.98 Sites of normal esophageal constrictions. EsophagusTracheaPharynxDiaphragmJunction of esophagus with pharynxWhere esophagus iscrossed by arch ofaortaWhere esophagus is compressed by left main bronchusAt the esophageal hiatusPosition ofesophagusposterior toleft atrium Fig. 3.99 Esophageal plexus. Fig. 3.100 Axial CT showing esophageal cancer. Fig. 3.101 Thoracic aorta and branches.
Anatomy_Gray. Fig. 3.95 Left vagus nerve passing through the superior mediastinum. Fig. 3.96 Left recurrent laryngeal nerve passing through the superior mediastinum. Left recurrent laryngeal nerveLeft vagus nerveRight mainbronchusTIV/VvertebrallevelLeft main bronchusLigamentum arteriosumLeft pulmonary arteryLeft subclavian arteryPulmonary trunkEsophagusEsophagusTracheaThoracic aortaArch of aorta Fig. 3.97 Esophagus. Right main bronchusLeft main bronchusLeft subclavian arteryLeft common carotid arteryEsophagusEsophagusTracheaThoracic aortaArch of aortaBrachiocephalic trunkDiaphragm Fig. 3.98 Sites of normal esophageal constrictions. EsophagusTracheaPharynxDiaphragmJunction of esophagus with pharynxWhere esophagus iscrossed by arch ofaortaWhere esophagus is compressed by left main bronchusAt the esophageal hiatusPosition ofesophagusposterior toleft atrium Fig. 3.99 Esophageal plexus. Fig. 3.100 Axial CT showing esophageal cancer. Fig. 3.101 Thoracic aorta and branches.
Anatomy_Gray_498
Anatomy_Gray
Fig. 3.99 Esophageal plexus. Fig. 3.100 Axial CT showing esophageal cancer. Fig. 3.101 Thoracic aorta and branches. Left subclavian arterySupremeintercostal arterySuperior leftbronchialarteryRightbronchialarteryEsophagusEsophagusTracheaArch of aortaPosteriorintercostalarteriesMediastinalbranchesEsophageal branches Fig. 3.102 Azygos system of veins. Left superior intercostal veinRight superior intercostal veinAccessory hemiazygos veinHemiazygos veinAzygos veinOpening of azygos veininto superior vena cavaPosterior intercostal veinRight subcostal veinAscending lumbar veinRight ascending lumbar veinInferior vena cava Fig. 3.103 Thoracic duct. Fig. 3.104 Thoracic portion of sympathetic trunks.
Anatomy_Gray. Fig. 3.99 Esophageal plexus. Fig. 3.100 Axial CT showing esophageal cancer. Fig. 3.101 Thoracic aorta and branches. Left subclavian arterySupremeintercostal arterySuperior leftbronchialarteryRightbronchialarteryEsophagusEsophagusTracheaArch of aortaPosteriorintercostalarteriesMediastinalbranchesEsophageal branches Fig. 3.102 Azygos system of veins. Left superior intercostal veinRight superior intercostal veinAccessory hemiazygos veinHemiazygos veinAzygos veinOpening of azygos veininto superior vena cavaPosterior intercostal veinRight subcostal veinAscending lumbar veinRight ascending lumbar veinInferior vena cava Fig. 3.103 Thoracic duct. Fig. 3.104 Thoracic portion of sympathetic trunks.
Anatomy_Gray_499
Anatomy_Gray
Fig. 3.103 Thoracic duct. Fig. 3.104 Thoracic portion of sympathetic trunks. Fig. 3.105 Anterior view of chest wall with the locations of skeletal structures shown. A. In women. The location of the nipple relative to a specific intercostal space varies depending on the size of the breasts, which may not be symmetrical. B. In men. Note the location of the nipple in the fourth intercostal space. ClavicleCostal cartilageCoracoid processCostal marginJugular notchSternoclavicular jointManubrium of sternumRib IRib XXiphoid processASternal angleIIIIIIVVVIVIIVIIIIXBody of sternum ClavicleCostal cartilageCoracoid processSternal angleCostal marginJugular notchSternoclavicular jointManubrium of sternumRib IRib XBody of sternumXiphoid processBIIIIIIVVVIVIIVIIIIX Fig. 3.106 A. Close-up view of nipple and surrounding areola of the breast. B. Lateral view of the chest wall of a woman showing the axillary process of the breast.
Anatomy_Gray. Fig. 3.103 Thoracic duct. Fig. 3.104 Thoracic portion of sympathetic trunks. Fig. 3.105 Anterior view of chest wall with the locations of skeletal structures shown. A. In women. The location of the nipple relative to a specific intercostal space varies depending on the size of the breasts, which may not be symmetrical. B. In men. Note the location of the nipple in the fourth intercostal space. ClavicleCostal cartilageCoracoid processCostal marginJugular notchSternoclavicular jointManubrium of sternumRib IRib XXiphoid processASternal angleIIIIIIVVVIVIIVIIIIXBody of sternum ClavicleCostal cartilageCoracoid processSternal angleCostal marginJugular notchSternoclavicular jointManubrium of sternumRib IRib XBody of sternumXiphoid processBIIIIIIVVVIVIIVIIIIX Fig. 3.106 A. Close-up view of nipple and surrounding areola of the breast. B. Lateral view of the chest wall of a woman showing the axillary process of the breast.