vena cava | anatomy | Britannica.com Vena cava hepatic vein Vena cava, in air-breathing vertebrates, including humans, either of two major trunks, the anterior and posterior venae cavae, that deliver oxygen-depleted blood to the right side of the heart. The anterior vena cava, also known as the precava, drains the head end of the body, while the posterior vena cava, or postcava, drains the tail, or rear, end. In humans these veins are respectively called the superior and inferior venae cavae. Whereas many mammals, including humans, have only one anterior vena cava, other animals have two. Superior vena cava. Not far below the collarbone and in back of the right side of the breastbone, two large veins, the right and left brachiocephalic, join to form the superior vena cava.

The brachiocephalic veins , as their name implies—being formed from the Greek words for “arm” and “head”—carry blood that has been collected from the head and neck and the arms; they also drain blood from much of the upper half of the body, including the upper part of the spine and the upper chest wall. A large vein , the azygos, which receives oxygen-poor blood from the chest wall and the bronchi, opens into the superior vena cava close to the point at which the latter passes through the pericardium, the sac that encloses the heart. The superior vena cava extends down about 7 cm (2.7 inches) before it opens into the right upper chamber—the right atrium of the heart. There is no valve at the heart opening. Inferior vena cava. The inferior vena cava is formed by the coming together of the two major veins from the legs, the common iliac veins , at the level of the fifth lumbar vertebra, just below the small of the back. Unlike the superior vena cava, it has a substantial number of tributaries between its point of origin and its terminus at the heart.

These include the veins that collect blood from the muscles and coverings of the loins and from the walls of the abdomen, from the reproductive organs, from the kidneys, and from the liver. In its course to the heart the inferior vena cava ascends close to the backbone; passes the liver, in the dorsal surface of which it forms a groove; enters the chest through an opening in the diaphragm; and empties into the right atrium of the heart at a non-valve opening below the point of entry for the superior vena cava. Learn More in these related articles: Venae Cavae - ECHOpedia Venae Cavae 6 References Inferior vena cava The inferior vena cava is the body's largest artery, which allows for the return flow of blood to the heart. This vein contains deoxygenated blood returning from the tissue in the lower part of the body (systemic circulation). The inferior vena cava subcostal is good to visualize. The VCI can be constricted by space-occupying processes, it is also called the VCI Syndrome.

Inferior vena cava diameter Respiratory failure In a normal RA pressure collapses the VCI in 80% of the cases, >40% (measured at the mouth of the hepatic vein). ±40% collapse VCI corresponds to a pressure of 8-10mmHg. At a collapse of 60-70%, the pressure in the VCI most often 2-4mmHg. At a collapse <40%, the VCI pressure >10mmHg (85%). When dilated, not collapsing VCI can pressure 20-25mmHg. Echocardiographic view M-mode collapse VCI Flow pattern Because in most cases VCI is perpendicular to the beam in the ultrasound image running, the flow pattern of the hepatic vein viewed . This is the same as VCI, only the hepatic vein is parallel to the sound beam . Normal hepatic vein flow Systolic flow reversal of the hepatic vein in severe TI [ 1 ] Superior vena cava The superior vena cava contains oxygen-poor blood returning from the tissue in the upper portion of the body (pulmonary circulation).

The superior vena cava is close to the roof of the right atrium. The superior vena cava is transthoracically not good to bring into image, only supraclavicular (no standard recording). Better to spend (the last part of) the VCS with TEE in image. The VCS can be constricted by space-occupying processes, it is also called the VCS Syndrome. Definition of Vena cava Definition of Vena cava Causes of a Heart Attack Slideshow Vena cava: The superior vena cava is the large vein which returns blood to the heart from the head, neck and both upper limbs. The inferior vena cava returns blood to the heart from the lower part of the body. The return of blood via the vena cava can be compromised and cause disease. For example, in the superior vena cava syndrome , the symptoms that result from compression of the large vein that carries blood down to the heart. The superior vena cava is located in the middle of the chest and is surrounded by rigid structures and lymph nodes.

The structure bordering the superior vena cava include the trachea, aorta, thymus, right bronchus of the lung and pulmonary artery. Compression of the superior vena cava by disease of any of the structures or lymph nodes surrounding the superior vena cava can cause the superior vena cava syndrome. The superior vena cava syndrome is characterized by swelling of the face, neck and/or arms with visible widening (dilation) of the veins of the neck. Patients often have a persistent cough and shortness of breath. Others symptoms can be present including hoarseness , swelling around the eyes, fatigue , chest pain , headaches, and dizziness . The causes of the superior vena cava syndrome include cancer (malignancies) and non-cancer (benign) conditions. The common forms of cancer that can cause the superior vena cava syndrome are lung cancer , lymphoma (cancer of the lymph nodes), and cancer that has spread (metastasis) to the chest, more commonly breast and testicular cancer .

Non-cancer causes of the superior vena cava syndrome include infections (such as tuberculosis , fungus, and syphilis), benign tumors (such as teratomas, thymoma , dermoid cyst), aortic aneurysm , pericarditis , sarcoidosis , irradiation treatment to the chest, air in the chest ( pneumothorax ), and complication of central line catheters and congenital heart surgery. Diagnosis of superior vena cava syndrome is supported by identifying a cause for the superior vena cava syndrome, typically requiring X- ray imaging or CAT or MRI scanning. Treatment of superior vena cava syndrome is directed toward the exact underlying cause. Therefore, treatment might include radiation treatment, antibiotics, chemotherapy , clot-busting (thrombolytic) drugs, blood thinners (anticoagulation), and balloon angioplasty, and even surgery. The outlook for patients with the superior vena cava syndrome clearly depends on the underlying cause of the syndrome.

Last Editorial Review: 5/13/2016 Inferior Vena Cava - Anatomy Pictures and Information Home > Cardiovascular System > Cardiovascular System of the Lower Torso > Inferior Vena Cava Inferior Vena Cava The inferior vena cava is the largest vein in the human body. It collects blood from veins serving the tissues inferior to the heart and returns this blood to the right atrium of the heart. Although the vena cava is very large in diameter, its walls are incredibly thin due to the low pressure exerted by venous blood. The inferior vena cava forms at the superior end of the pelvic cavity when the common iliac veins unite to form a larger vein. From the pelvis, the inferior vena cava ascends through the posterior abdominal body wall just to the right of the vertebral column.... Move up/down/left/right: Click compass arrows Rotate image: Click and drag in any direction, anywhere in the frame Identify objects: Click on them in the image 2D Interactive 3D Rotate & Zoom Change Anatomical System Change View Angle Full Inferior Vena Cava Description [Continued from above] . . .

Along its way through the abdomen, blood from the internal organs joins the inferior vena cava through a series of large veins, including the gonadal, renal, suprarenal and inferior phrenic veins. The hepatic vein provides blood from the digestive organs of the abdomen after it has passed through the hepatic portal system in the liver. Blood from the tissues of the lower back, including the spinal cord and muscles of the back, enters the vena cava through the lumbar veins. Many smaller veins also provide blood to the vena cava from the tissues of the abdominal body wall. Upon reaching the heart, the inferior vena cava connects to the right atrium on its posterior side, inferior to the connection of the superior vena cava. The inferior vena cava and its tributaries drain blood from the feet, legs, thighs, pelvis and abdomen and deliver this blood to the heart. Many one-way venous valves help to move blood through the veins of the lower extremities against the pull of gravity. Blood passing through the veins is under very little pressure and so must be pumped toward the heart by the contraction of skeletal muscles in the legs and by pressure in the abdomen caused by breathing.

Venous valves help to trap blood between muscle contractions or breaths and prevent it from being pulled back down towards the feet by gravity. Prepared by Tim Taylor, Anatomy and Physiology Instructor Inferior Vena Cava Function, Anatomy & Definition | Body Maps Your message has been sent. OK We're sorry, an error occurred. We are unable to collect your feedback at this time. However, your feedback is important to us. Please try again later. Close Inferior vena cava The inferior vena cava is also referred to as the posterior vena cava. The inferior vena cava is a large vein that carries de-oxygenated blood from the lower body to the heart. De-oxygenated blood means most of the oxygen has been removed by tissues, and therefore the blood is darker. This blood comes from the legs and the lower torso of the body. The inferior vena cava empties into the right atrium of the heart. The right atrium is located on the lower right back side of the heart. The inferior vena cava runs posterior, or behind, the abdominal cavity. This vein also runs alongside the right vertebral column of the spine.

The inferior vena cava is the result of two major leg veins coming together. These leg veins are called iliac veins. The iliac veins come together at the small of the back, at the fifth lumbar vertebra. Once the iliac veins have merged, the inferior vena cava begins to transport blood to the heart. Venae cavae - definition of venae cavae by The Free Dictionary Venae cavae - definition of venae cavae by The Free Dictionary Related to venae cavae: caliology vena ca·va (kā′və) n. pl. venae ca·vae (kā′vē) Either of two large veins that drain blood from the upper body and from the lower body and empty into the right atrium of the heart. [New Latin vēna cava : Latin vēna, vein + Latin cava, hollow.] vena ca′val (-vəl) adj. vena cava n, pl venae cavae (ˈkeɪviː) (Anatomy) either one of the two large veins that convey oxygen-depleted blood to the heart [Latin: hollow vein] n., pl.

ve•nae ca•vae (ˈvi ni ˈkeɪ vi) either of two large veins discharging blood into the right atrium of the heart. [1590–1600; < Latin vēna cava hollow vein] ve·na ca·va (vē′nə kā′və) Either of two large veins that carry blood with low levels of oxygen to the right atrium of the heart. The lower one, called the inferior vena cava, is the largest vein in the body. ThesaurusAntonymsRelated WordsSynonymsLegend: Noun 1.

vena cava - either of two large veins that return oxygen-depleted blood to the right atrium of the heart vein , vena , venous blood vessel - a blood vessel that carries blood from the capillaries toward the heart; "all veins except the pulmonary vein carry unaerated blood" inferior vena cava , postcava - receives blood from lower limbs and abdominal organs and empties into the posterior part of the right atrium of the heart; formed from the union of the two iliac veins precava , superior vena cava - receives blood from the head and arms and chest and empties into the right atrium of the heart; formed from the azygos and both brachiocephalic veins Translations Sinus of venae cavae | definition of sinus of venae cavae by Medical dictionary Sinus of venae cavae | definition of sinus of venae cavae by Medical dictionary sinus [si´nus] 1. a recess, cavity, or channel, such as one in bone or a dilated channel for venous blood. 2. an abnormal channel or fistula, permitting escape of pus. 3. paranasal sinus .

anal s's furrows, with pouchlike recesses at the distal end, separating the rectal columns ; called also anal crypts . anterior s's (sinus anterio´res) the anterior air cells that together with the middle and posterior air cells form the ethmoidal sinus. aortic s's pouchlike dilatations at the root of the aorta, one opposite each semilunar cusp of the aortic valve, from which the coronary arteries originate. carotid sinus a dilatation of the proximal portion of the internal carotid or distal portion of the common carotid artery, containing in its wall pressoreceptors that are stimulated by changes in blood pressure. See also carotid sinus syndrome . cavernous sinus an irregularly shaped venous channel between the layers of dura mater of the brain, one on either side of the body of the sphenoid bone and communicating across the midline. Several cranial nerves course through this sinus. cerebral sinus one of the ventricles of the brain. cervical sinus a temporary depression in the neck of the embryo containing the branchial arches.

circular sinus the venous channel encircling the pituitary gland, formed by the two cavernous sinuses and the anterior and posterior intercavernous sinuses. coccygeal sinus a sinus or fistula just over or close to the tip of the coccyx. coronary sinus the dilated terminal portion of the great cardiac vein, receiving blood from other veins draining the heart muscle and emptying into the right atrium. dermal sinus a congenital sinus tract extending from the surface of the body, between the bodies of two adjacent lumbar vertebrae, to the spinal canal. ethmoid s's (ethmoidal s's) ethmoid cells. frontal sinus one of the paired paranasal sinuses in the frontal bone, each communicating with the middle nasal meatus on the same side. intercavernous s's channels connecting the two cavernous sinuses, one passing anterior and the other posterior to the stalk of the pituitary gland. lymphatic s's irregular, tortuous spaces within lymphoid tissues through which lymph flows. maxillary sinus one of the paired paranasal sinuses in the body of the maxilla on either side, opening into the middle nasal meatus on the same side.

occipital sinus a venous sinus between the layers of dura mater, passing upward along the midline of the cerebellum. paranasal s's the eight cavities in the skull that are connected with the nasal cavity (see also Plates). They are arranged in four pairs, each of which has one member on the left and one on the right. The pairs are the maxillary sinuses in the maxillae; the frontal sinuses in the frontal bone; the sphenoid sinuses in the sphenoid bone behind the nasal cavity; and the ethmoid cells (ethmoid sinuses) in the ethmoid bone behind and below the frontal sinuses. The functions of the sinuses are not certain. They are believed to help the nose in circulating, warming, and moistening the air as it is inhaled, thereby lessening the shock of cold, dry air to the lungs. They also are thought to have a minor role as resonating chambers for the voice. Sinus paranasal (Paranasal sinuses). From Dorland's, 2000. petrosal sinus, inferior a venous channel arising from the cavernous sinus and draining into the internal jugular vein.

petrosal sinus, superior one arising from the cavernous sinus and draining into the transverse sinus of the dura mater. pilonidal sinus pilonidal cyst . prostatic sinus the posterolateral recess between the seminal colliculus and the wall of the urethra, where the prostatic ductules empty into the urethra. s's of pulmonary trunk spaces between the wall of the pulmonary trunk and cusps of the pulmonary valve at its opening from the right ventricle. renal sinus a recess in the substance of the kidney, occupied by the renal pelvis, calices, vessels, nerves, and fat. sagittal sinus, inferior a small venous sinus of the dura mater, opening into the straight sinus. sagittal sinus, superior a venous sinus of the dura mater that ends in the confluence of sinuses. sigmoid sinus a venous sinus of the dura mater on either side, continuous with the straight sinus and draining into the internal jugular vein of the same side. sphenoid sinus (sphenoidal sinus) one of the paired paranasal sinuses in the body of the sphenoid bone, opening into the superior nasal meatus on the same side.

sphenoparietal sinus one of the venous sinuses of the dura mater, emptying into the cavernous sinus. s's of spleen dilated venous sinuses found in the splenic pulp; they are not lined by ordinary endothelial cells. straight sinus a venous sinus of the dura mater formed by junction of the great cerebral vein and inferior sagittal sinus, and ending in the confluence of sinuses. tarsal sinus a space between the calcaneus and talus. tentorial sinus straight sinus . transverse sinus of dura mater a large venous sinus on either side of the brain. transverse sinus of pericardium a passage within the pericardial sac, behind the aorta and pulmonary trunk and in front of the left atrium and superior vena cava. tympanic sinus a deep recess on the medial wall of the middle ear. urogenital sinus an elongated sac that is formed by division of the cloaca in the early embryo, which ultimately forms most of the vestibule, urethra, and vagina in the female, and some of the urethra in the male. uterine s's venous channels in the wall of the uterus in pregnancy.

uteroplacental s's blood spaces between the placenta and uterine sinuses. sinus of venae cavae the posterior portion of the right atrium into which the inferior and the superior vena cava open; called also sinus venosus . sinus veno´sus (venous sinus) 3. sinus of venae cavae . venous s's of dura mater large channels for venous blood forming an anastomosing system between the layers of the dura mater of the brain, receiving blood from the brain and draining into the veins of the scalp or deep veins at the base of the skull. venous sinus of sclera a circular channel at the junction of the sclera and cornea, into which aqueous humor filters from the anterior chamber of the eye. Called also Schlemm's canal . si·nus si·nus·es (sī'nŭs, -ĕz), The plural of this word is sinus, not sini. 1. A channel for the passage of blood or lymph, without the coats of an ordinary vessel; for example, blood passages in the gravid uterus or those in the cerebral meninges. 2.

A cavity or hollow space in bone or other tissue. 3. A dilation in a blood vessel. 4. A fistula or tract leading to a suppurating cavity. [L. sinus, cavity, channel, hollow] sinus /si·nus/ (si´nus) pl. si´nus, sinuses [L.] 1. a recess, cavity, or channel, as (a) one in bone or (b) a dilated channel for venous blood. 2. an abnormal channel or fistula permitting escape of pus.si´nusal air sinus an air-containing space within a bone. anal sinuses furrows, with pouchlike openings at the distal end, separating the rectal columns. aortic sinus a dilatation between the aortic wall and each of the semilunar cusps of the aortic valve; from two of these sinuses the coronary arteries originate. branchial sinus an abnormal cavity or space opening externally on the inferior third of the neck; usually a result of persistence of the second pharyngeal groove and cervical sinus.

carotid sinus a dilatation of the proximal portion of the internal carotid or distal portion of the common carotid artery, containing in its wall pressoreceptors which are stimulated by changes in blood pressure. Carotid sinus (sinus caroticus) and carotid arteries in a deep dissection of the right side of the neck. cavernous sinus either of two irregularly shaped sinuses of the dura mater, located at either side of the body of the sphenoid bone and communicating across the midline; it contains the internal carotid artery and abducent nerve. cervical sinus a temporary depression caudal to the second pharyngeal arch, containing the succeeding pharyngeal arches; it is overgrown by the second pharyngeal arch and closes off as the cervical vesicle. circular sinus the venous channel encircling the hypophysis, formed by the two cavernous sinuses and the anterior and posterior intercavernous sinuses. coccygeal sinus a sinus or fistula just over or close to the tip of the coccyx.

coronary sinus the terminal portion of the great cardiac vein, lying in the coronary sulcus between the left atrium and ventricle, and emptying into the right atrium. cortical sinuses lymph sinuses in the cortex of a lymph node, which arise from the marginal sinuses and continue into the medullary sinuses. dermal sinus a congenital sinus tract extending from the surface of the body, between the bodies of two adjacent lumbar vertebrae, to the spinal canal. dural sinuses large venous channels forming an anastomosing system between the layers of the dura mater, draining the cerebral veins and some diploic and meningeal veins into the veins of the neck. sinus of epididymis a long, slitlike serous pocket between the upper part of the testis and the overlying epididymis . ethmoid sinuses , ethmoidal sinuses see under cell . frontal sinus one of the paired paranasal sinuses in the frontal bone, each communicating with the middle meatus of the ipsilateral nasal cavity.

intercavernous sinuses two sinuses of the dura mater connecting the two cavernous sinuses, one passing anterior and the other posterior to the infundibulum of the hypophysis. lacteal sinuses , lactiferous sinuses enlargements of the lactiferous ducts just before they open on the mammary papilla. lymphatic sinuses irregular, tortuous spaces within lymphoid tissue (nodes) through which lymph passes, to enter efferent lymphatic vessels. marginal sinuses 1. see under lake . 2. bowl-shaped lymph sinuses separating the capsule from the cortical parenchyma, and from which lymph flows into the cortical sinuses. maxillary sinus one of the paired paranasal sinuses in the body of the maxilla on either side, and opening into the middle meatus of the ipsilateral nasal cavity. medullary sinuses lymph sinuses in the medulla of a lymph node, which divide the lymphoid tissue into a number of medullary cords. occipital sinus one of the sinuses of the dura mater, passing upward along the midline of the cerebellum. oral sinus stomodeum .

paranasal sinuses mucosa-lined air cavities in bones of the skull, communicating with the nasal cavity and including ethmoidal, frontal, maxillary, and sphenoidal sinuses. Paranasal sinuses (sinus paranasales). petrosal sinus either of two sinuses of the dura mater, arising from the cavernous sinus and draining into the internal jugular vein (inferior petrosal s.) or into the transverse sinus (superior petrosal s.). pilonidal sinus a suppurating sinus containing hair, occurring chiefly in the coccygeal region. prostatic sinus the posterolateral recess between the seminal colliculus and the wall of the urethra. sinus of pulmonary trunk a slight dilatation between the wall of the pulmonary trunk and each of the semilunar cusps of the pulmonary trunk valve. renal sinus a recess in the substance of the kidney, occupied by the renal pelvis, calices, vessels, nerves, and fat. sagittal sinus, inferior a small venous sinus of the dura mater, opening into the straight sinus. sagittal sinus, superior a venous sinus of the dura mater which ends in the confluence of sinuses.

sigmoid sinus a venous sinus of the dura mater on either side, continuous with the transverse sinus and draining into the internal jugular vein of the same side. sphenoid sinus , sphenoidal sinus one of the paired paranasal sinuses in the body of the sphenoid bone and opening into the highest meatus of the ipsilateral nasal cavity. sphenoparietal sinus either of two sinuses of the dura mater, draining into the anterior part of the cavernous sinus. sinus of spleen a dilated venous sinus in the substance of the spleen. straight sinus one of the sinuses of the dura mater formed by junction of the great cerebral vein and inferior sagittal sinus, commonly ending in the confluence of the sinuses. tarsal sinus a space between the calcaneus and talus. terminal sinus a vein that encircles the vascular area in the blastoderm. transverse sinus 1. either of two large sinuses of the dura mater. 2. a passage behind the aorta and pulmonary trunk and in front of the atria. tympanic sinus a deep recess in the posterior part of the tympanic cavity.

urogenital sinus an elongated sac formed by division of the cloaca in the early embryo, forming most of the bladder, the female vestibule, urethra, and vagina, and most of the male urethra. uterine sinuses venous channels in the wall of the uterus in pregnancy. sinus of venae cavae the portion of the right atrium into which the inferior and the superior venae cavae open. sinus veno´sus 1. the common venous receptacle in the embryonic midheart, attached to the posterior wall of the primordial atrium. 2. s. venosus (1). venous sinuses of dura mater large channels for venous blood forming an anastomosing system between the layers of the dura mater of the brain, receiving blood from the brain and draining into the veins of the scalp or deep veins at the base of the skull. venous sinus of sclera a branching, circumferential vessel in the internal scleral sulcus, a major component of the drainage pathway for aqueous humor. sinus 1. A depression or cavity formed by a bending or curving. 2. Anatomy a.

A dilated channel or receptacle containing chiefly venous blood. b. Any of various air-filled cavities in the bones of the skull, especially one communicating with the nostrils. 3. Medicine A fistula leading from a pus-filled cavity. 4. Botany A recess or indentation between two lobes or segments, as of a leaf. sinus [sī′nəs] Etymology: L, hollow a cavity or channel, such as a cavity within a bone, a dilated channel for venous blood, or one permitting the escape of purulent material. sinus A hollow cavity, sac, pouch or opening, such as urogenital sinus; a cavity or hollow space in a tissue or organ (e.g., bone). si·nus , pl. sinus, sinuses (sī'nŭs, -ĕz) 1. A channel for the passage of blood or lymph, without the coats of an ordinary vessel, e.g., blood passages in the gravid uterus or those in the cerebral meninges. 2. A cavity or hollow space in bone or other tissue. 3. A dilation in a blood vessel. 4. A fistula or tract leading to a suppurating cavity. [L.

sinus, cavity, channel, hollow] sinus (si'nus) plural.sinuses, sinus [L., sinus, curve, hollow] 1. A recess. 2. A cavity with a narrow opening. 3. An endothelia-lined, air-filled cavity within a bone. (When nonmedical people speak of 'sinuses', they are generally referring to this type of sinus, specifically, to the paranasal sinuses.) 4. An endothelia-lined channel for venous blood. 5. A channel leading to an abscess. accessory nasal sinus anal sinus Any of the saclike recesses on the inner lining of the anal canal between the anal columns. aortic sinus Inside the aorta, the pouch behind each of the three leaflets of the aortic valve. The right and left coronary arteries each originate from an orifice in an aortic sinus, leaving one aortic sinus (the noncoronary sinus) as a blind pouch. Synonym: sinus of Valsalva basilar sinus Transverse sinus (2). carotid sinus The small dilation at the base of the internal carotid artery with baroreceptors in its wall.

These receptors respond to changes in arterial blood pressure, and their signals are carried to the hindbrain by the glossopharyngeal nerve (CN IX). sinus cavernosus Cavernous sinus. cavernous sinus A 1 cm wide dural sinus extending 2 cm along the medial wall of the base of the middle cranial fossa. The cavernous sinus empties into (a) the transverse sinus via the superior petrosal sinus, (b) the internal jugular vein via the inferior petrosal sinus, (c) the pterygoid plexus via emissary veins, and (d) the facial vein via the superior ophthalmic vein. The right and left cavernous sinuses are interconnected by the anterior and posterior intercavernous sinuses. Tributaries of the cavernous sinus include the superior ophthalmic, superficial middle cerebral, and inferior cerebral veins and the sphenoparietal sinus. Synonym: sinus cavernosus Dural sinus. circular sinus A set of four interconnected dural sinuses encircling the sella turcica and pituitary gland at the base of the brain.

The four sinuses are the right and left cavernous sinuses and the anterior and posterior intercavernous sinuses. coccygeal sinus A sinus in the midline of the gluteal cleft just over the coccyx. confluence of the sinuses The dilated posterior end of the superior sagittal sinus in the skull. This dilation joins one of the transverse sinuses (usually the right), which drains the blood from the superior sagittal sinus toward the internal jugular vein. The other transverse sinus and the occipital sinus also connect to the confluence of the sinuses.) coronary sinus A large vein on the posterior surface of the heart; it runs in the atrioventricular groove between the left atrium and left ventricle. Most of the blood feeding the heart returns to the right atrium via the coronary sinus. Its direct tributaries include the small, middle, and great cardiac veins. cranial sinus Any of the large veins between the two layers of the cranial dura mater. cranial venous sinus A congenital sinus tract connecting the surface of the body with the spinal canal. draining sinus An abnormal passageway leading from inside the body to the outside.

This is usually due to an infectious process. dural sinus Any of several large endothelia-lined collecting channels into which veins of the brain and inner skull empty and which then empty into the internal jugular vein. These venous sinuses are found between the two layers (periosteal and meningeal) of the dura mater. Their walls have no muscle, and they have no valves to give direction to the blood flow. The venous sinuses in the skull include the superior sagittal, inferior sagittal, straight, transverse, and cavernous sinuses. Synonym: cerebral sinus; dural venous sinus dural venous sinus Dural sinus. ethmoid sinus Any of the 3-18 paranasal sinuses on each side of the skull in and adjacent to the ethmoid bone. The ethmoid sinuses can be categorized as anterior, middle, or posterior, with each group usually draining into a different part of the nasal cavity. Ethmoid sinuses have very thin walls and are interconnected via openings in the septa between the sinuses. frontal sinus Either of a pair of paranasal sinuses in the frontal bones just above the orbits.

These sinuses lie adjacent to each other in the midline, but are usually completely separated by a bony septum. Each frontal sinus drains into the ipsilateral nasal cavity through an opening in the lateral wall along the middle nasal passageway (i.e., middle nasal meatus). genitourinary sinus Urogenital sinus. hair sinus The sinus formed when hair is embedded in the skin and acts as a foreign body. inferior longitudinal sinus Inferior sagittal sinus. inferior petrosal sinus A dural sinus that drains the cavernous sinus posteriorly into the superior jugular bulb of the internal jugular vein. inferior sagittal sinus An unpaired midline dural sinus running along the lower, free margin of the falx cerebri (over the top of the corpus callosum). It drains blood from veins in the falx and from the medial surfaces of the hemispheres, and it empties, posteriorly, into the straight sinus. intercavernous sinus The anterior and the posterior intercavernous sinuses interconnect the right and left cavernous sinuses at the base of the brain.

All sinuses are valveless; thus, the cavernous and intercavernous sinuses form a circle -- the circular sinus -- that enwraps the sella turcica. lactiferous sinus Immediately inside the tip of the nipple, the dilated end of any of the 15-20 lactiferous ducts, which convey milk from the mammary glands during lactation. lateral sinus Either of two large venous sinuses in the inner side of the skull passing near the mastoid antrum and emptying into the jugular vein. lymph sinus Endothelia-lined channels through which lymph flows inside lymph nodes. The walls of lymph sinuses are coated with T and B lymphocytes as well as phagocytic cells, all of which filter the passing lymph. Lymphocytes and macrophages move in and out of the lymph through the sinus walls. Synonym: lymph channel marginal sinus 1. Considered together, the many dilated veins or venous "lakes" that collect blood in the intervillous space of the placenta; the marginal sinus drains into the uterine veins. 2.

A dural sinus along the inside of the rim of the foramen magnum; it drains into the vertebral venous plexus. 3. A blood-filled sinus in the marginal zone of the spleen. In the passage from the red pulp to the white pulp, some arterial blood flows along (and percolates through) the endothelia-lined walls of the marginal sinus before entering the arterial capillary beds of the white pulp. mastoid sinus An old term for the mastoid antrum. maxillary sinus Either of a pair of paranasal sinuses filling the bodies of the maxillary bones. The maxillary sinuses are large and pyramidal shaped, with average dimensions of 3.5 cm x 2.5 cm x 3.2 cm. The medial floor of the maxillary sinus is immediately above the roots of the first and second upper molars. Each maxillary sinus drains into the ipsilateral nasal cavity through an opening in the lateral wall of the hiatus semilunaris, under the middle nasal concha. Synonym: antrum of Highmore occipital sinus A slender dural sinus running in the posterior, i.e., attached, margin of the falx cerebelli.

It begins near the foramen magnum, and it ascends along the midline of the occipital bone. The occipital sinus empties into the confluence of the sinuses. PARANASAL SINUS paranasal sinus An air cavity in a facial bone, either the frontal, maxillary, sphenoid, or ethmoid bones; most paranasal sinuses occur in pairs. The paranasal sinuses are lined with ciliated epithelium that secretes mucus. The sinuses open into the lateral walls of the nasal cavities via small holes. Healthy paranasal sinuses are radiolucent. Synonym: accessory nasal sinus; air sinus; See: illustration illustration pericardial sinus The oblique or the transverse pericardial sinus, which are spaces between the visceral and parietal layers of the serous pericardium. The oblique sinus runs along the posterior surface of the left atrium between the orifices of the right and the left pulmonary veins. The transverse sinus runs along the posterior surface of the base of the heart between the outflow vessels (the aorta and the pulmonary trunk) in front and the inflow vessels (the pulmonary veins) behind.

petrosal sinus The superior or the inferior petrosal sinus. pilonidal sinus Pilonidal fistula. pleural sinus Any of the spaces in the pleural sac along the lower and inferior portions of the lung that the lung does not occupy. sinus pocularis A lacuna in the prostatic part of the urethra. Synonym: sinus prostaticus sinus prostaticus Sinus pocularis. pulmonary sinus Either of the pouches within the pulmonic trunk behind each of the three leaflets of the pulmonic valve. sinus rectus Straight sinus. renal sinus The indentation on the medial side of each kidney into which the hilum leads; the renal sinus is largely filled by the renal pelvis. rhomboid sinus The superior or the inferior sagittal sinus. sigmoid sinus The continuation of the transverse sinus downward along the wall of the posterior cranial fossa to the jugular canal; there, the sigmoid sinus becomes the superior jugular bulb, the origin of the internal jugular vein. sphenoid sinus Either of a pair of paranasal sinuses in the sphenoid bone just above and behind the nasal cavity.

The sphenoid sinuses are located adjacent to the optic chiasm, the pituitary gland, and the internal carotid arteries. Each sphenoid sinus drains through an opening in the sphenoethmoidal recess at the very top of the ipsilateral nasal cavity. sphenoparietal sinus A venous sinus uniting the cavernous sinus and a meningeal vein. sinus of spleen A large-capacity venous channel in the spleen. straight sinus An unpaired midline dural sinus where the falx cerebri and the tentorium cerebelli meet. The straight sinus is the posterior continuation of the inferior sagittal sinus. The straight sinus empties into the transverse sinus contralateral to the one joined by the superior sagittal sinus; nonetheless, the straight sinus often communicates, if only through a small channel, with the confluence of the sinuses. Synonym: sinus rectus A slender dural sinus that drains the cavernous sinus posteriorly into the transverse sinus. superior sagittal sinus A long unpaired midline channel through the superior margin of the falx cerebri.

It begins in the front near the crista galli of the ethmoid bone, and it extends along the entire inner roof of the skull to the internal occipital protuberance in the back. Its posterior end, called the confluence of the sinuses, is dilated and usually joins the right transverse sinus; however, the other transverse sinus and the occipital sinus also communicate with the confluence of the sinuses. Tributaries of the superior sagittal sinus include ascending frontal cerebral veins, superior cerebral veins, diploic veins draining the skull bones, and a number of irregularly shaped venous lacunae. Numerous arachnoid granulations (sites of the return of water and filtrate from the cerebrospinal fluid) protrude into the superior sagittal sinus. tarsal sinus A space between the top of the calcaneus bone and the bottom of the tarsal bone. Synonym: tarsal sinus A vein encircling the vascular area of the blastoderm. transverse sinus A dural sinus in the lateral edge of the tentorium cerebelli along each lateral upper border of the posterior cranial fossa.

One transverse sinus (usually the right) is a continuation of the superior sagittal sinus; the other transverse sinus (typically the smaller of the two) is the continuation of the inferior sagittal sinus, although both transverse sinuses usually have a connection near their origin, in the region of the confluence of sinuses. The transverse sinuses run anteriorly and turn downward to become the sigmoid sinuses at the front edges of the tentorium cerebelli; at this point, the transverse sinuses are joined by the superior petrosal sinuses. Tributaries of the transverse sinuses include inferior cerebral, inferior cerebellar, and diploic veins. sinus tympani A recess in the medial wall of the tympanic cavity beside the promontory and adjacent to the round window. The sinus tympani can be > 3 mm deep. urogenital sinus In the embryo, a space behind the urogenital membrane (a surface structure) and separated from the future rectum by the urorectal septum (an internal structure). The urachus and the mesonephric ducts, i.e., the Wolffian ducts, open into the urogenital sinus.

The sinus will later give rise to major parts of the urinary bladder, urethra, vagina, and genitourinary tract glands. uterine sinus Any of the venous channels in the walls of the uterus during pregnancy. uteroplacental sinus Any of the slanting venous channels from the placenta serving to convey the maternal blood from the intervillous lacunae back into the uterine veins. sinus of Valsalva Aortic sinus. sinus of venal canal The portion of the right atrium of the heart posterior, and to the left of, the crista terminalis. The inferior and superior vena caval veins empty into it. sinus venosus In the embryo, the portion of the developing heart tube that leads into the cavities destined to form the atria and ventricles. The major embryonic veins — umbilical, vitelline, and common cardinal — all lead into the sinus venosum. Later, the sinus venosum will become the posterior smooth wall of the right atrium, including the openings from the coronary sinus and the venae cava. venous sinus A valveless irregularly shaped venous channel lined by endothelial cells.

Large venous sinuses include the coronary sinus of the heart and the dural sinuses inside the skull; small venous sinuses are found inside certain tissues, such as the spleen. sinus 1. One of the paired mucous membrane-lined air cavities in a bone, specifically the frontal sinuses in the forehead, the maxillary sinuses (antrums) in the cheek bones, the multicelled ethmoidal sinuses on either side of the upper part of the nose and the sphenoidal sinuses in the base of the skull. 2. Any wide blood channel such as the venous sinuses in the MENINGES . 3. Any tract or FISTULA leading from a deep infected area to a surface. sinus (in plants) a depression or margin between two lobes of a leaf. (in animals) a cavity within a bone, such as that in the human facial bone. (in animals) a large blood-filled cavity such as the HAEMOCOEL of ARTHROPODS or enlarged veins of fish. Sinus Air-filled cavities surrounding the eyes and nose are lined with mucus-producing membranes. They cleanse the nose, add resonance to the voice, and partially determine the structure of the face.

Mentioned in: Abscess , Erythromycins , Nasal Polyps , Sinusitis sinus fistula/tract leading from one body cavity to another or from a body cavity to the exterior, e.g. tract connecting an infected area of osteomyelitis to the skin surface sinus A hollow space in bone or other tissue. cavernous sinus One of the two venous sinuses in the dura mater of the brain extending on each side of the pituitary body, behind the orbit. It receives blood from the superior and the inferior ophthalmic veins and the central retinal veins. The third, fourth, fifth and sixth nerves pass through as well as the internal carotid artery. The cavernous plexus is located within this sinus. See carotid-cavernous fistula . sinus circularis iridis See Schlemm's canal . ethmoidal sinus Mucus-lined air cavities within the ethmoid bone, between the nose and the orbit. They drain into the nasal cavity. They contain the anterior and posterior ethmoidal nerves and blood vessels and are filled with air.

They are separated from adjacent areas by very thin plates through which infection can pass easily and in particular ethmoiditis, which is the most common cause of orbital cellulitis. sinus venosus sclerae See Schlemm's canal . si·nus , pl. sinus, pl. sinuses (sī'nŭs, -ĕz) The plural of this word is sinus, not sini. 1. [TA] Channel for the passage of blood or lymph, without the coats of an ordinary vessel; e.g., blood passages in gravid uterus or those in cerebral meninges. 2. [TA] Cavity or hollow space in bone or other tissue. 3. Fistula or tract leading to a suppurating cavity. [L. sinus, cavity, channel, hollow] sinus (sī´nus), n a cavity, recess, or hollow space. sinus, alveolar, n a passage connecting a pathologic cavity in the alveolus with the oral or nasal cavity and penetrating the mucous membrane. See also fistula, alveolar. sinus balloon, n See balloon, sinus.

sinus, carotid, n the swelling in the artery just before the common carotid artery bifurcates into the internal and external carotid arteries. sinus, coronary, n the venous sinus in the groove between the left cardiac auricle and the left ventricle. sinus(es), ethmoidal n an air space located within the ethmoid bone, which comprises the floor of the skull and the roof of the nose. There are four ethmoid sinuses: the anterior, middle, and two posterior sinuses. The anterior and middle sinuses drain directly into the middle meatus (opening) of the nose. The posterior sinuses drain into the superior meatus of the nose. sinus(es), frontal, n an air space located within the frontal bone of the forehead. sinus(es), maxillary (antrum of Highmore, maxillary antrum), n a large pyramidal cavity within the body of the maxilla. Its walls are thin and correspond to the orbital, nasal anterior, and infratemporal surfaces of the body of the maxilla.

On dental radiographs the floor of the sinus is often observed approximating the root apices of the teeth and is seen to extend from the canine or premolar region posteriorly to the molar or tuberosity region. sinus(es), paranasal, n the paired air cavities in various bones around the nose, including the maxillary sinus within the maxilla, the sphenoid sinus in the sphenoid bone, the ethmoid sinuses in the ethmoid bone, and the frontal sinus in the frontal bone. sinus(es), sphenoid n an air space located within the wing-like sphenoid bone, located at the base of the skull. These sinuses are variable in shape and size, and are rarely symmetrical because of lateral displacement of the septum. sinus tract, n See tract, sinus. sinus pneumatization n an enlargement of the maxillary sinus, usually as part of the aging process and as a result of the loss of maxillary teeth. sinus 1. a recess, cavity, or channel, as (a) one in bone or (b) a dilated, valveless channel for venous blood. 2. an abnormal channel or fistula, permitting escape of pus.

In common, unqualified usage, the word sinus refers to any of the cavities in the skull that are connected with the nasal cavity—the paranasal sinuses. anal s's furrows, with pouchlike recesses at their distal ends, separating the rectal columns; called also anal crypts. basilar sinus a dural venous sinus which runs on the floor of the cranial cavity and out through the foramen magnum. cavernous sinus an irregularly shaped venous channel between the layers of dura mater of the brain, one on either side of the body of the sphenoid bone and communicating across the midline. Several cranial nerves and, when present, the rete mirabile, course through this sinus. cavernous sinus syndrome lesions of the cavernous syndrome, caused by neoplasia or infectious agents, result in a dilated pupil and paralysis of the globe; vision is usually spared. cerebral sinus one of the ventricles of the brain. cervical sinus a temporary depression in the neck of the embryo containing the branchial arches.

circular sinus the venous channel encircling the pituitary gland, formed by the two cavernous sinuses and the anterior and posterior intercavernous sinuses. conchal sinus cavity of the conchal bone. coronary sinus the terminal portion of the great cardiac vein, which lies in the cardiac sulcus between the left atrium and ventricle, and empties into the right atrium. dermoid sinus, dermal sinus a large dural venous sinus located within the falx cerebri. dura mater venous sinus large channels for venous blood forming an anastomosing system between the layers of the dura mater of the brain. ethmoidal sinus that paranasal sinus consisting of the ethmoidal cells collectively, and communicating with the nasal meatuses. facial sinus see malar abscess. frontal sinus one of the paired paranasal sinuses in the frontal bone, each communicating with the middle meatus of the ipsilateral nasal cavity. hair sinus see sinus hair . infraorbital sinus an air-filled recess in the head of birds which lies lateral to the nasal cavity into which it opens.

intercavernous sinus channels connecting the two cavernous sinuses, one passing anterior and the other posterior to the stalk of the pituitary gland. interdigitalis sinus the cutaneous pouch, which lies between the claws of sheep and some other ruminants and whose wall contains apocrine glands, and whose duct surfaces on the skin just above the coronets; it serves as a trail gland. lymphatic sinus irregular, tortuous spaces within lymphoid tissues through which lymph flows. maxillary sinus one of the paired paranasal sinuses in the body of the maxilla on either side, opening into the middle meatus of the ipsilateral nasal cavity. In the horse it is divided into two compartments that communicate independently with the nasal chambers. All other sinuses of the horse communicate with the nasal chambers via the caudal maxillary sinus. nasal sinus see paranasal sinuses (below). sinus nerve a branch of the glossopharyngeal nerve; carries the afferent fibers of the stretch receptors in the wall of the carotid sinus. sinus node see sinoatrial node. occipital sinus a venous sinus between the layers of dura mater, passing along the midline of the cerebellum.

paranasal s's mucosa-lined air cavities in bones of the skull, communicating with the nasal cavity and including ethmoidal, frontal, maxillary and sphenoidal sinuses. petrosal sinus (inferior) a venous channel arising from the cavernous sinus and draining into the internal jugular vein. petrosal sinus (superior) one arising from the cavernous sinus and draining into the transverse sinus of the dura mater. prostatic sinus the dorsolateral recess between the seminal colliculus and the wall of the urethra. pulmonary trunk sinus spaces between the wall of the pulmonary trunk and cusps of the pulmonary valve at its opening from the right ventricle. red pulp sinus vascular storage in the spleen into which capillaries empty. sinus reflex arc afferent fibers are in the sinus nerve; these connect with the cardioinhibitory and vasomotor centers which control blood pressure and heart rate via sympathetic fibers to blood vessels; provides a route for the sinus reflex which relates pressure in the carotid sinus to the performance of the circulatory system. renal sinus a recess in the substance of the kidney, occupied by the renal pelvis, calices, vessels, nerves and fat.

sagittal sinus (inferior) a small venous sinus of the dura mater of large animals found between the cerebral hemispheres and opening into the straight sinus. sagittal sinus (superior) a venous sinus of the dura mater that courses between the cerebral hemispheres and ends in the confluence of sinuses. scleral venous sinus see schlemm's canal . sigmoid sinus a venous sinus of the dura mater on either side, continuous with the straight sinus and draining into the internal jugular vein of the same side. sphenoidal sinus one of the paired paranasal sinuses in the body of the sphenoid bone of some species. In the horse it communicates with the nasal cavity via the frontal and caudal maxillary sinuses. sphenoparietal sinus one of the venous sinuses of the dura mater, emptying into the cavernous sinus. splenic sinus dilated venous channels in the substance of the spleen. See also red pulp sinus (above). straight sinus a venous sinus of the dura mater formed by junction of the great cerebral vein and inferior sagittal sinus, and ending in the confluence of sinuses.

tarsal sinus a space between the calcaneus and talus. tentorial sinus straight sinus. transverse dura mater sinus a large venous sinus that runs in the attached border of the cerebellar tentorium on either side of the skull. transverse pericardial sinus a passage within the pericardial sac, between the aorta and pulmonary trunk cranioventrally, and the left atrium and cranial vena cava dorsally. tympanic sinus a deep recess on the medial wall of the middle ear. urachal sinus an anomalous closure of the urachal canal in the newborn in which the opening at the umbilicus remains open. The bladder is normal. It is the cause of persistent infection and swelling at the umbilicus in the young animal and may lead to cystitis and pyelonephritis. urethral s a small cavity in the glans penis of the horse, above the urethral process; as a recess of the fossa glandis it is usually filled with a small mass (bean) of inspissated smegma.

urogenital sinus an elongated sac formed by division of the cloaca in the early embryo, which ultimately forms most of the vestibule, urethra and vagina in the female, and some of the urethra in the male. uterine sinus venous channels in the wall of the uterus in pregnancy. uteroplacental sinus blood spaces between the placenta and uterine sinuses. venae caval sinus the posterior portion of the right atrium into which the inferior and the superior vena cava open. sinus venarum a chamber which is the greater part of the right atrium into which the great veins discharge. venous sinus, sinus venosus 1. the common venous receptacle in the heart of the early embryo that receives blood from the umbilical and vitelline veins and from the body via the ducts of Cuvier. 2. sinus of venae cavae. vertebral sinus a continuation of part of the common occipital vein in birds; it emerges from the foramen magnum and accompanies the vertebral vein. Patient discussion about sinus Q. I have been having chronic pain in sinus area and behind my eyes, been to ENT who states it is not infection?

I wake up with the pain and go to sleep in severe pain. Its all day and all night. Dr insists that its migraine related and allergy related. I have chronic postnasal drainage. It started 4 months ago when I moved into our new house. The pain makes me extremely fatigue and dizzy at times. I have been referred to the eye doctor, a headache specialist and an allergy specialist. Just recently I have had a CT scan and an MRI, as well as xrays of my sinus. Nothing other than a deviated septum and possible allergies from an ENT has been diagnosed. In the mean time I am waiting for the days to come when I can get into see these specialist. Anyone out there have any of the same symptoms?? Need help here. Soooooo sick of the pain. A. i have chronic sinusitis and can really relate to what you describe. learned to live with the pain...but still, i use various ways to reduce inflammation in my sinuses, i heat the place up before going to sleep, try to avoid eating or drinking cold stuff.

another thing i do is i heat water (80c) then add a special oil i bought in a chinese medicine store , about 5 drops, and inhale the fumes. nettle tea can do wonders too.

Question: The "venae cavae" are found in what part of the body?
Answer: Heart