The Intestines (Human Anatomy): Picture, Function, Location, Parts, Definition, and Conditions Next The intestines are a long, continuous tube running from the stomach to the anus. Most absorption of nutrients and water happen in the intestines. The intestines include the small intestine, large intestine, and rectum. The small intestine (small bowel) is about 20 feet long and about an inch in diameter. Its job is to absorb most of the nutrients from what we eat and drink. Velvety tissue lines the small intestine, which is divided into the duodenum, jejunum, and ileum. The large intestine (colon or large bowel) is about 5 feet long and about 3 inches in diameter. The colon absorbs water from wastes, creating stool. As stool enters the rectum, nerves there create the urge to defecate. Intestine Conditions Stomach flu (enteritis): Inflammation of the small intestine. Infections (from viruses, bacteria, or parasites) are the common cause. Small intestine cancer : Rarely, cancer may affect the small intestine. There are multiple types of small intestine cancer, causing about 1,100 deaths each year.

Celiac disease : An "allergy" to gluten (a protein in most breads) causes the small intestine not to absorb nutrients properly. Abdominal pain and weight loss are usual symptoms. Carcinoid tumor : A benign or malignant growth in the small intestine. Diarrhea and skin flushing are the most common symptoms. Intestinal obstruction : A section of either the small or large bowel can become blocked or twisted or just stop working. Belly distension, pain, constipation, and vomiting are symptoms. Colitis : Inflammation of the colon. Inflammatory bowel disease or infections are the most common causes. Diverticulosis : Small weak areas in the colon's muscular wall allow the colon's lining to protrude through, forming tiny pouches called diverticuli. Diverticuli usually cause no problems, but can bleed or become inflamed. Diverticulitis : When diverticuli become inflamed or infected, diverticulitis results. Abdominal pain and constipation are common symptoms. Colon bleeding (hemorrhage): Multiple potential colon problems can cause bleeding. Rapid bleeding is visible in the stool, but very slow bleeding might not be.

Inflammatory bowel disease : A name for either Crohn's disease or ulcerative colitis. Both conditions can cause colon inflammation (colitis). Crohn's disease : An inflammatory condition that usually affects the colon and intestines. Abdominal pain and diarrhea (which may be bloody) are symptoms. Ulcerative colitis : An inflammatory condition that usually affects the colon and rectum. Like Crohn's disease, bloody diarrhea is a common symptom of ulcerative colitis. Diarrhea : Stools that are frequent, loose, or watery are commonly called diarrhea. Most diarrhea is due to self-limited, mild infections of the colon or small intestine. Salmonellosis : Salmonella bacteria can contaminate food and infect the intestine. Salmonella causes diarrhea and stomach cramps, which usually resolve without treatment. Shigellosis : Shigella bacteria can contaminate food and infect the intestine. Symptoms include fever, stomach cramps, and diarrhea, which may be bloody. Traveler's diarrhea : Many different bacteria commonly contaminate water or food in developing countries. Loose stools, sometimes with nausea and fever, are symptoms. Colon polyps : Polyps are growths inside the colon.

Colon cancer can often develop in these tumors after many years. Colon cancer : Cancer of the colon affects more than 100,000 Americans each year. Most colon cancer is preventable through regular screening. Rectal cancer : Colon and rectal cancer are similar in prognosis and treatment. Doctors often consider them together as colorectal cancer. Constipation : When bowel movements are infrequent or difficult. Irritable bowel syndrome (IBS): Irritable bowel syndrome, also known as IBS, is an intestinal disorder that causes irritable abdominal pain or discomfort, cramping or bloating, and diarrhea or constipation. Rectal prolapse : Part or all of the wall of the rectum can move out of position, sometimes coming out of the anus, when straining during a bowel movement. Intussusception : Occurring mostly in children, the small intestine can collapse into itself like a telescope. It can become life-threatening if not treated. Continued Intestine Tests Capsule endoscopy : A person swallows a capsule that contains a camera.

The camera takes pictures of possible problems in the small intestine, sending the images to a receiver worn on the persons belt Upper endoscopy , EGD (esophagogastroduodenoscopy): A flexible tube with a camera on its end (endoscope) is inserted through the mouth. The endoscope allows examination of the duodenum, stomach, and esophagus. Colonoscopy : An endoscope is inserted into the rectum and advanced through the colon. A doctor can examine the entire colon with a colonoscope. Virtual colonoscopy : A test in which an X-ray machine and a computer create images of the inside of the colon. If problems are found, a traditional colonoscopy is usually needed. Fecal occult blood testing : A test for blood in the stool. If blood is found in the stool, a colonoscopy may be needed to look for the source. Sigmoidoscopy : An endoscope is inserted into the rectum and advanced through the left side of the colon. Sigmoidoscopy cannot be used to view the middle and right sides of the colon. Colon biopsy : During a colonoscopy, a small piece of colon tissue may be removed for testing.

A colon biopsy can help diagnose cancer, infection, or inflammation. Intestine Treatments Antidiarrheal agents : Various medicines can slow down diarrhea, reducing discomfort. Reducing diarrhea does not slow down recovery for most diarrheal illnesses. Stool softeners : Over-the-counter and prescription medicines can soften the stool and reduce constipation. Laxatives : Medicines can relieve constipation by a variety of methods including stimulating the bowel muscles, and bringing in more water. Enema: A term for pushing liquid into the colon through the anus. Enemas can deliver medicines to treat constipation or other colon conditions. Colonoscopy : Using tools passed through an endoscope, a doctor can treat certain colon conditions. Bleeding, polyps, or cancer might be treated by colonoscopy. Polypectomy : During colonoscopy, removal of a colon polyp is called polypectomy. Colon surgery : Using open or laparoscopic surgery, part or all of the colon may be removed (colectomy). This may be done for severe bleeding, cancer, or ulcerative colitis.

WebMD Image Collection Reviewed by Varnada Karriem-Norwood, MD on November 15, 2014 Sources SOURCES Herliner, H., Maglinte, D., Birnbaum, B., and Balthazar, E. Clinical Imaging of the Small Intestine, Springer, Nov. 30, 2001. The Physics Factbook web site: "Length of a Human Intestine." Dummies.com: "Running Through the Human Digestive System." National Cancer Institute: "Small Intestine Cancer," "Colon and Rectal Cancer." National Digestive Diseases Information Clearinghouse: "Celiac Disease," "Colonoscopy," "Flexible Sigmoidoscopy," "Diverticulosis and Diverticulitis." Medscape: "Obstruction, Small Bowel." The Stomach (Human Anatomy): Picture, Function, Definition, Conditions, and More Human Anatomy Next The stomach is a muscular organ located on the left side of the upper abdomen. The stomach receives food from the esophagus. As food reaches the end of the esophagus, it enters the stomach through a muscular valve called the lower esophageal sphincter.

The stomach secretes acid and enzymes that digest food. Ridges of muscle tissue called rugae line the stomach. The stomach muscles contract periodically, churning food to enhance digestion. The pyloric sphincter is a muscular valve that opens to allow food to pass from the stomach to the small intestine. Stomach Conditions Gastroesophageal reflux : Stomach contents, including acid, can travel backward up the esophagus. There may be no symptoms, or reflux may cause heartburn or coughing. Gastroesophageal reflux disease (GERD) : When symptoms of reflux become bothersome or occur frequently, they’re called GERD. Infrequently, GERD can cause serious problems of the esophagus. Dyspepsia : Another name for stomach upset or indigestion. Dyspepsia may be caused by almost any benign or serious condition that affects the stomach. Gastric ulcer (stomach ulcer) : An erosion in the lining of the stomach, often causing pain and/or bleeding. Gastric ulcers are most often caused by NSAIDs or H. pylori infection.

Peptic ulcer disease : Doctors consider ulcers in either the stomach or the duodenum (the first part of the small intestine) peptic ulcer disease. Gastritis : Inflammation of the stomach, often causing nausea and/or pain. Gastritis can be caused by alcohol, certain medications, H. pylori infection, or other factors. Stomach cancer : Gastric cancer is an uncommon form of cancer in the U.S. Adenocarcinoma and lymphoma make up most of the cases of stomach cancer. Zollinger-Ellison syndrome (ZES) : One or more tumors that secrete hormones that lead to increased acid production. Severe GERD and peptic ulcer disease result from this rare disorder. Gastric varices: In people with severe liver disease, veins in the stomach may swell and bulge under increased pressure. Called varices, these veins are at high risk for bleeding, although less so than esophageal varices are. Stomach bleeding : Gastritis, ulcers, or gastric cancers may bleed. Seeing blood or black material in vomit or stool is usually a medical emergency.

Gastroparesis (delayed gastric emptying) : Nerve damage from diabetes or other conditions may impair the stomach’s muscle contractions. Nausea and vomiting are the usual symptoms. Continued Stomach Tests Upper endoscopy (esophagogastroduodenoscopy or EGD) : A flexible tube with a camera on its end (endoscope) is inserted through the mouth. The endoscope allows examination of the esophagus, stomach, and duodenum (the first part of the small intestine). Computed tomography (CT scan) : A CT scanner uses X-rays and a computer to create images of the stomach and abdomen. Magnetic resonance imaging : Using a magnetic field, a scanner creates high-resolution images of the stomach and abdomen. pH testing : Using a tube through the nose into the esophagus, acid levels in the esophagus can be monitored. This can help diagnose or change treatment for GERD. Barium swallow : After swallowing barium, X-ray films of the esophagus and stomach are taken. This can sometimes diagnose ulcers or other problems. Upper GI series : X-rays are taken of the esophagus, stomach, and upper part of the small intestine.

Gastric emptying study: A test of how rapidly food passes through the stomach. The food is labeled with a chemical and viewed on a scanner. Stomach biopsy : During an endoscopy, a doctor can take a small piece of stomach tissue for tests. This can diagnose H. pylori infection, cancer, or other problems. H. pylori test : While most people with H. pylori infection don't develop ulcers, simple blood or stool tests can be done to check for infection in people with ulcers or to verify that the infection is wiped out after treatment.. Stomach Treatments Histamine (H2) blockers : Histamine increases stomach acid secretion; blocking histamine can reduce acid production and GERD symptoms. Proton pump inhibitors : These medicines directly inhibit the acid pumps in the stomach. They must be taken daily to be effective. Antacids : These medicines can help against the effects of acid but don't kill bacteria or stop acid production. Endoscopy : During an upper endoscopy, tools on the endoscope can sometimes stop stomach bleeding, if present. Motility agents : Medicines can increase contraction of the stomach, improving symptoms of gastroparesis.

Stomach surgery : Cases of severe stomach bleeding, ruptured ulcers, or cancer require surgery to be cured. Antibiotics : H. pylori infection can be cured with antibiotics, which are taken with other medicines to heal the stomach. WebMD Image Collection Reviewed by William Blahd, MD on March 04, 2016 Sources To which part of the small intestine does the stomach connect? | Reference.com To which part of the small intestine does the stomach connect? A: Quick Answer According to MedlinePlus, the stomach is connected to the first part of the small intestine, which is called the duodenum. Food mixes with stomach acid and moves to the duodenum, where bile is mixed in from the gallbladder and digestive juices come from the pancreas. Full Answer MedlinePlus states that the duodenum is also where minerals, vitamins and other nutrients begin to be absorbed from food. WebMD explains that the small intestine is divided into the duodenum, the jejunum and the ileum. The small intestine measures approximately 20 feet in length and 1 inch in diameter. The large intestine measures approximately 5 feet in length and 3 inches in diameter.

What is the Small Intestine? - Anatomy and Functions - Video & Lesson Transcript | Study.com What is the Small Intestine? - Anatomy and Functions Watch short & fun videos Start Your Free Trial Today An error occurred trying to load this video. Try refreshing the page, or contact customer support. You must create an account to continue watching Register for a free trial Are you a student or a teacher? I am a student Start Your Free Trial To Continue Watching As a member, you'll also get unlimited access to over lessons in math, English, science, history, and more. Plus, get practice tests, quizzes, and personalized coaching to help you succeed. Coming up next: What Is the Pancreas? - Function, Enzymes & Role in Digestion You're on a roll. Keep up the good work! Your next lesson will play in 10 seconds 0:05 Small Intestine 2:27 Ileum and Peyer's Patches 4:10 Lesson Summary Add to Add to Add to Want to watch this again later? Log in or sign up to add this lesson to a Custom Course. Custom Courses are courses that you create from Study.com lessons.

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Create an account to start this course today Try it free for 5 days! Lesson Transcript Instructor: Rebecca Gillaspy Dr. Gillaspy has taught health science at University of Phoenix and Ashford University and has a degree from Palmer College of Chiropractic. In this lesson, you will learn about the three divisions of the small intestine - the duodenum, jejunum, and ileum. You will also gain an understanding of the basic functions of each of these sections, including their role in removing bacteria. Small Intestine We previously learned that food you ingest begins to break down in the mouth. Once food is mixed with saliva, it is passed down through the pharynx and esophagus to the stomach where it is broken down further. Even though the food has now been in your digestive system for a few hours and has gone through a fair amount of processing, only a small portion of total digestion has taken place and even less absorption of nutrients. This fact is about to change as we take a look at the anatomy and functions of the small intestines. The first and middle sections of the small intestine The small intestine is the section of your digestive tract where the majority of food digestion and nutrient absorption takes place.

To understand how digestion and absorption take place in the small intestine, it is important to first understand the structure or anatomy of the organ. Your small intestine follows a twisty path and takes up much of the space within your abdomen. You can see from this picture that it appears to be framed by the large intestine. It is by far the longest section of your alimentary canal, measuring approximately twenty feet, and it is divided into three sections. Duodenum The duodenum is the first part of the small intestine immediately beyond the stomach. The duodenum is the shortest of the three divisions of your small intestine, but its small size does not mean that it's not important. In fact, it is the duodenum that receives many of the digestive juices needed to break down foods into nutrients that are small enough to be absorbed by your body. This makes the duodenum the section of the small intestine where the majority of the chemical digestion of food takes place. Jejunum The middle section of the small intestine is called the jejunum. We saw that the duodenum was the section of the small intestine where the majority of the chemical breakdown of nutrients took place.

Now that these nutrients have been broken down into their smallest units, they can be absorbed through the wall of the jejunum and dropped into the blood stream to be carried to the cells of your body. Therefore, we see the jejunum as a prominent site for nutrient absorption. Peyers patches on the ileum To help you remember the order of these first two sections, you might want to remember that their names, duodenum and jejunum, start with the letters D and J. Since a DJ is the one at the party that gets the action started, you can think of the first two sections of the small intestine as the part of your digestive tract that gets things started. Ileum and Peyer's Patches The terminal section of the small intestine is called the ileum. The word ileum is Latin for groin, and because the ileum is the lowest section of the small intestine and found near the groin, this can help you remember the term. The ileum follows the jejunum, and it provides additional area for the absorption of nutrients. The ileum also provides a place for the absorption of vitamin B12 and bile salts.

One interesting modification that we see as we move into the ileum is the presence of local collections of lymphatic tissues called Peyer's patches. Peyer's patches are named after the person who first discovered them, a Swiss anatomist named Johann Conrad Peyer. Because our lymphatic system helps us fight bacteria and other foreign invaders, we see that the presence of lymphatic structures here in the ileum reflects the fact that the remaining food that has passed this far through the digestive tract contains a high number of bacteria. These Peyer's Patches act to prevent bacteria from entering the bloodstream. Undigested food moves through the ileocecal valve to the large intestine × The Stomach - Human Anatomy FIG. 1046 Outline of stomach, showing its anatomical landmarks. (Ventriculus; Gaster) The stomach is the most dilated part of the digestive tube, and is situated between the end of the esophagus and the beginning of the small intestine. It lies in the epigastric, umbilical, and left hypochondriac regions of the abdomen, and occupies a recess bounded by the upper abdominal viscera, and completed in front and on the left side by the anterior abdominal wall and the diaphragm.

The shape and position of the stomach are so greatly modified by changes within itself and in the surrounding viscera that no one form can be described as typical. The chief modifications are determined by (1) the amount of the stomach contents, (2) the stage which the digestive process has reached, (3) the degree of development of the gastric musculature, and (4) the condition of the adjacent intestines. It is, however, possible by comparing a series of stomachs to determine certain markings more or less common to all (Figs. 1046, 1047, 1048, 1049). The stomach presents two openings, two borders or curvatures, and two surfaces. Openings.The opening by which the esophagus communicates with the stomach is known as the cardiac orifice, and is situated on the left of the middle line at the level of the tenth thoracic vertebra. The short abdominal portion of the esophagus (antrum cardiacum) is conical in shape and curved sharply to the left, the base of the cone being continuous with the cardiac orifice of the stomach.

The right margin of the esophagus is continuous with the lesser curvature of the stomach, while the left margin joins the greater curvature at an acute angle, termed the incisura cardiaca. The pyloric orifice communicates with the duodenum, and its position is usually indicated on the surface of the stomach by a circular groove, the duodenopyloric constriction. This orifice lies to the right of the middle line at the level of the upper border of the first lumbar vertebra. Curvatures.The lesser curvature (curvatura ventriculi minor), extending between the cardiac and pyloric orifices, forms the right or posterior border of the stomach. It descends as a continuation of the right margin of the esophagus in front of the fibers of the right crus of the diaphragm, and then, turning to the right, it crosses the first lumbar vertebra and ends at the pylorus. Nearer its pyloric than its cardiac end is a well-marked notch, the incisura angularis, which varies somewhat in position with the state of distension of the viscus; it serves to separate the stomach into a right and a left portion.

The lesser curvature gives attachment to the two layers of the hepatogastric ligament, and between these two layers are the left gastric artery and the right gastric branch of the hepatic artery. The greater curvature (curvatura ventriculi major) is directed mainly forward, and is four or five times as long as the lesser curvature. Starting from the cardiac orifice at the incisura cardiaca, it forms an arch backward, upward, and to the left; the highest point of the convexity is on a level with the sixth left costal cartilage. From this level it may be followed downward and forward, with a slight convexity to the left as low as the cartilage of the ninth rib; it then turns to the right, to the end of the pylorus. Directly opposite the incisura angularis of the lesser curvature the greater curvature presents a dilatation, which is the left extremity of the pyloric part; this dilatation is limited on the right by a slight groove, the sulcus intermedius, which is about 2.5 cm, from the duodenopyloric constriction.

The portion between the sulcus intermedius and the duodenopyloric constriction is termed the pyloric antrum. At its commencement the greater curvature is covered by peritoneum continuous with that covering the front of the organ. The left part of the curvature gives attachment to the gastrolienal ligament, while to its anterior portion are attached the two layers of the greater omentum, separated from each other by the gastroepiploic vessels. Surfaces.When the stomach is in the contracted condition, its surfaces are directed upward and downward respectively, but when the viscus is distended they are directed forward, and backward. They may therefore be described as anterosuperior and postero-inferior. Antero-superior Surface.The left half of this surface is in contact with the diaphragm, which separates it from the base of the left lung, the pericardium, and the seventh, eighth, and ninth ribs, and intercostal spaces of the left side. The right half is in relation with the left and quadrate lobes of the liver and with the anterior abdominal wall. When the stomach is empty, the transverse colon may lie on the front part of this surface.

The whole surface is covered by peritoneum. The Postero-inferior Surface is in relation with the diaphragm, the spleen, the left suprarenal gland, the upper part of the front of the left kidney, the anterior surface of the pancreas, the left colic flexure, and the upper layer of the transverse mesocolon. These structures form a shallow bed, the stomach bed, on which the viscus rests. The transverse mesocolon separates the stomach from the duodenojejunal flexure and small intestine. The postero-inferior surface is covered by peritoneum, except over a small area close to the cardiac orifice; this area is limited by the lines of attachment of the gastrophrenic ligament, and lies in apposition with the diaphragm, and frequently with the upper portion of the left suprarenal gland. Component Parts of the Stomach.A plane passing through the incisura angularis on the lesser curvature and the left limit of the opposed dilatation on the greater curvature divides the stomach into a left portion or body and a right or pyloric portion.

The left portion of the body is known as the fundus, and is marked off from the remainder of the body by a plane passing horizontally through the cardiac orifice. The pyloric portion is divided by a plane through the sulcus intermedius at right angles to the long axis of this portion; the part to the right of this plane is the pyloric antrum (Fig. 1046). FIG. 1047 Diagram showing shape and position of empty stomach. Erect posture. (Hertz.) If the stomach be examined during the process of digestion it will be found divided by a muscular constriction into a large dilated left portion, and a narrow contracted tubular right portion. The constriction is in the body of the stomach, and does not follow any of the anatomical landmarks; indeed, it shifts gradually toward the left as digestion progresses, i. e., more of the body is gradually absorbed into the tubular part (Figs. 1047, 1048, 1049). FIG. 1048 Diagram showing shape and position of moderately filled stomach. Erect posture. (Hertz.) FIG.

1049 Diagram showing shape and position of distended stomach. Erect posture. (Hertz.) Position of the Stomach.The position of the stomach varies with the posture, with the amount of the stomach contents and with the condition of the intestines on which it rests. In the erect posture the empty stomach is somewhat J-shaped; the part above the cardiac orifice is usually distended with gas; the pylorus descends to the level of the second lumbar vertebra and the most dependent part of the stomach is at the level of the umbilicus. Variation in the amount of its contents affects mainly the cardiac portion, the pyloric portion remaining in a more or less contracted condition during the process of digestion. As the stomach fills it tends to expand forward and downward in the direction of least resistance, but when this is interfered with by a distended condition of the colon or intestines the fundus presses upward on the liver and diaphragm and gives rise to the feelings of oppression and palpitation complained of in such cases.

His (* 166 and Cunningham (* 167 have shown by hardening the viscera in situ that the contracted stomach has a sickle shape, the fundus looking directly backward. The surfaces are directed upward and downward, the upper surface having, however, a gradual downward slope to the right. The greater curvature is in front and at a slightly higher level than the lesser. The position of the full stomach depends, as already indicated, on the state of the intestines; when these are empty the fundus expands vertically and also forward, the pylorus is displaced toward the right and the whole organ assumes an oblique position, so that its surfaces are directed more forward and backward. The lowest part of the stomach is at the pyloric vestibule, which reaches to the region of the umbilicus. Where the intestines interfere with the downward expansion of the fundus the stomach retains the horizontal position which is characteristic of the contracted viscus.

Examination of the stomach during life by x-rays has confirmed these findings, and has demonstrated that, in the erect posture, the full stomach usually presents a hook-like appearance, the long axis of the clinical fundus being directed downward, medialward, and forward toward the umbilicus, while the pyloric portion curves upward to the duodenopyloric junction. Interior of the Stomach.When examined after death, the stomach is usually fixed at some temporary stage of the digestive process. A common form is that shown in Fig. 1050. If the viscus be laid open by a section through the plane of its two curvatures, it is seen to consist of two segments: (a) a large globular portion on the left and (b) a narrow tubular part on the right. These correspond to the clinical subdivisions of fundus and pyloric portions already described, and are separated by a constriction which indents the body and greater curvature, but does not involve the lesser curvature.

To the left of the cardiac orifice is the incisura cardiaca: the projection of this notch into the cavity of the stomach increases as the organ distends, and has been supposed to act as a valve preventing regurgitation into the esophagus. In the pyloric portion are seen: (a) the elevation corresponding to the incisura angularis, and (b) the circular projection from the duodenopyloric constriction which forms the pyloric valve; the separation of the pyloric antrum from the rest of the pyloric part is scarcely indicated. FIG. 1050 Interior of the stomach. The pyloric valve (valvula pylori) is formed by a reduplication of the mucous membrane of the stomach, covering a muscular ring composed of a thickened portion of the circular layer of the muscular coat. Some of the deeper longitudinal fibers turn in and interlace with the circular fibers of the valve. Structure.The wall of the stomach consists of four coats: serous, muscular, areolar, and mucous, together with vessels and nerves.

The serous coat (tunica serosa) is derived from the peritoneum, and covers the entire surface of the organ, excepting along the greater and lesser curvatures at the points of attachment of the greater and lesser omenta; here the two layers of peritoneum leave a small triangular space, along which the nutrient vessels and nerves pass. On the posterior surface of the stomach, close to the cardiac orifice, there is also a small area uncovered by peritoneum, where the organ is in contact with the under surface of the diaphragm. The muscular coat (tunica muscularis) (Figs. 1051, 1052) is situated immediately beneath the serous covering, with which it is closely connected. It consists of three sets of smooth muscle fibers: longitudinal, circular and oblique. The longitudinal fibers (stratum longitudinale) are the most superficial, and are arranged in two sets. The first set consists of fibers continuous with the longitudinal fibers of the esophagus; they radiate in a stellate manner from the cardiac orifice and are practically all lost before the pyloric portion is reached.

The second set commences on the body of the stomach and passes to the right, its fibers becoming more thickly distributed as they approach the pylorus. Some of the more superficial fibers of this set pass on to the duodenum, but the deeper fibers dip inward and interlace with the circular fibers of the pyloric valve. FIG. 1051 The longitudinal and circular muscular fibers of the stomach, viewed from above and in front. (Spalteholz.) FIG. 1052 The oblique muscular fibers of the stomach, viewed from above and in front. (Spalteholz.) The circular fibers (stratum circulare) form a uniform layer over the whole extent of the stomach beneath the longitudinal fibers. At the pylorus they are most abundant, and are aggregated into a circular ring, which projects into the lumen, and forms, with the fold of mucous membrane covering its surface, the pyloric valve. They are continuous with the circular fibers of the esophagus, but are sharply marked off from the circular fibers of the duodenum.

The oblique fibers (fibræ obliquæ) internal to the circular layer, are limited chiefly to the cardiac end of the stomach, where they are disposed as a thick uniform layer, covering both surfaces, some passing obliquely from left to right, others from right to left, around the cardiac end. The areolar or submucous coat (tela submucosa) consists of a loose, areolar tissue, connecting the mucous and muscular layers. The mucous membrane (tunica mucosa) is thick and its surface is smooth, soft, and velvety. In the fresh state it is of a pinkish tinge at the pyloric end, and of a red or reddish-brown color over the rest of its surface. In infancy it is of a brighter hue, the vascular redness being more marked. It is thin at the cardiac extremity, but thicker toward the pylorus. During the contracted state of the organ it is thrown into numerous plaits or rugæ, which, for the most part, have a longitudinal direction, and are most marked toward the pyloric end of the stomach, and along the greater curvature (Fig. 1050).

These folds are entirely obliterated when the organ becomes distended. FIG. 1053 Section of mucous membrane of human stomach, near the cardiac orifice. (v. Ebner, after J. Schaffer.) X 45. c. Cardiac glands. d. Their ducts. cr. Gland similar to the intestinal glands, with goblet cells. mm. Mucous membrane. m. Muscularis mucosæ. m. Muscular tissue within the mucous membrane. Structure of the Mucous Membrane.When examined with a lens, the inner surface of the mucous membrane presents a peculiar honeycomb appearance from being covered with small shallow depressions or alveoli, of a polygonal or hexagonal form, which vary from 0.12 to 0.25 mm. in diameter. These are the ducts of the gastric glands, and at the bottom of each may be seen one or more minute orifices, the openings of the gland tubes. The surface of the mucous membrane is covered by a single layer of columnar epithelium with occasional goblet cells.

This epithelium commences very abruptly at the cardiac orifice, where there is a sudden transition from the stratified epithelium of the esophagus. The epithelial lining of the gland ducts is of the same character and is continuous with the general epithelial lining of the stomach (Fig. 1055). The Gastric Glands.The gastric glands are of three kinds: (a) pyloric, (b) cardiac, and (c) fundus or oxyntic glands. They are tubular in character, and are formed of a delicate basement membrane, consisting of flattened transparent endothelial cells lined by epithelium. The pyloric glands (Fig. 1054) are found in the pyloric portion of the stomach. They consist of two or three short closed tubes opening into a common duct or mouth. These tubes are wavy, and are about one-half the length of the duct. The duct is lined by columnar cells, continuous with the epithelium lining the surface of the mucous membrane of the stomach, the tubes by shorter and more cubical cell which are finely granular. The cardiac glands (Fig.

1053), few in number, occur close to the cardiac orifice. They are of two kinds: (1) simple tubular glands resembling those of the pyloric end of the stomach, but with short ducts; (2) compound racemose glands resembling the duodenal glands. The fundus glands (Fig. 1055) are found in the body and fundus of the stomach; they are simple tubes, two or more of which open into a single duct. The duct, however, in these glands is shorter than in the pyloric variety, sometimes not amounting to more than one-sixth of the whole length of the gland; it is lined throughout by columnar epithelium. The gland tubes are straight and parallel to each other. At the point where they open into the duct, which is termed the neck, the epithelium alters, and consists of short columnar or polyhedral, granular cells, which almost fill the tube, so that the lumen becomes suddenly constricted and is continued down as a very fine channel. They are known as the chief or central cells of the glands.

Between these cells and the basement membrane, larger oval cells, which stain deeply with eosin, are found; these cells are studded throughout the tube at intervals, giving it a beaded or varicose appearance. These are known as the parietal or oxyntic cells, and they are connected with the lumen by fine channels which run into their substance. Between the glands the mucous membrane consists of a connective-tissue frame-work, with lymphoid tissue. In places, this later tissue, especially in early life, is collected into little masses, which to a certain extent resemble the solitary nodules of the intestine, and are termed the lenticular glands of the stomach. They are not, however, so distinctly circumscribed as the solitary nodules. Beneath the mucous membrane, and between it and the submucous coat, is a thin stratum of involuntary muscular fiber (muscularis mucosæ), which in some parts consists only of a single longitudinal layer; in others of two layers, an inner circular and an outer longitudinal. FIG. 1054 A pyloric gland, from a section of the dogs stomach. (Ebstein.) m. Mouth. n.

Neck. tr. A deep portion of a tubule cut transversely. FIG. 1055 A fundus gland. A. Transverse section of gland. Vessels and Nerves.The arteries supplying the stomach are: the left gastric, the right gastric and right gastroepiploic branches of the hepatic, and the left gastroepiploic and short gastric branches of the lienal. They supply the muscular coat, ramify in the submucous coat, and are finally distributed to the mucous membrane. The arrangement of the vessels in the mucous membrane is somewhat peculiar. The arteries break up at the base of the gastric tubules into a plexus of fine capillaries which run upward between the tubules, anastomosing with each other, and ending in a plexus of larger capillaries, which surround the mouths of the tubes, and also form hexagonal meshes around the ducts. From these the veins arise, and pursue a straight course downward, between the tubules, to the submucous tissue; they end either in the lienal and superior mesenteric veins, or directly in the portal vein.

The lymphatics are numerous: they consist of a superficial and a deep set, and pass to the lymph glands found along the two curvatures of the organ (page 706). The nerves are the terminal branches of the right and left vagi, the former being distributed upon the back, and the latter upon the front part of the organ. A great number of branches from the celiac plexus of the sympathetic are also distributed to it. Nerve plexuses are found in the submucous coat and between the layers of the muscular coat as in the intestine. From these plexuses fibrils are distributed to the muscular tissue and the mucous membrane. Note 166. Archiv für Anatomie und Physiologie, anat. Abth., 1903. [ back ] Note 167. Transactions of the Royal Society of Edinburgh, vol. xlv, part i. [ back ] Abdomen anatomy, problems, tests and treatments Abdomen anatomy, problems, tests and treatments The abdomen may be better known as the tummy or belly. It covers the area between the chest (thorax) and the pelvis.

The diaphragm forms the upper surface of the abdomen. When you get to the pelvic bones , the abdomen ends and the pelvis begins. The abdomen contains all the digestive organs, including the stomach , small and large intestines , pancreas , liver , and gallbladder . These organs are held together loosely by connecting tissues (mesentery) that allow them to expand and to slide against each other. The abdomen also contains the kidneys and spleen. Many important blood vessels travel through the abdomen, including the aorta , inferior vena cava, and dozens of their smaller branches. In the front, the abdomen is protected by a thin, tough layer of tissue called fascia. In front of the fascia are the abdominal muscles and skin . In the rear of the abdomen are the back muscles. Abdomen conditions Peritonitis: Inflammation of the covering of the abdominal structures, causing rigidity and severe pain . Usually, this is due to a ruptured or infected abdominal organ. Acute abdomen: A medical phrase doctors use to suggest that peritonitis is present and surgery is likely needed. Appendicitis : Inflammation of the appendix that is attached to the large intestine , and located in the lower right side of the abdomen.

Usually, an inflamed appendix must be removed by surgery. Cholecystitis: Inflammation of the gallbladder, causing severe right-sided abdominal pain . A gallstone blocking the duct exiting the gallbladder is usually responsible. Dyspepsia: The feeling of an upset stomach or indigestion . Dyspepsia can result from benign or more serious conditions. Constipation : Having fewer, and producing less, bowel movements than usual. Gastritis : Inflammation of the stomach, often causing nausea and/or pain . Gastritis can be caused by alcohol, nonsteroidal anti-inflammatory drugs ( NSAIDs ), Helicobacter pylori (H. pylori) infection or other factors. Peptic ulcer disease: Ulcers are erosions and peptic refers to acid. Peptic ulcers are ulcers in the stomach and duodenum (the first part of the small intestine). The usual cause is either an infection with H. pylori or side effects of regularly taking anti-inflammatory medication like ibuprofen or aspirin . Intestinal obstruction: A single area of the small or large intestine can become blocked or the entire intestine may stop working. Vomiting and abdominal distension are symptoms.

Stomach and Duodenum | Organs | MUSC Digestive Disease Center Map/Directions Stomach and Duodenum The stomach is a J-shaped sac connecting the esophagus above and the small intestine below. The first part of the small intestine is known as the duodenum. The stomach varies considerably in size, shape and position but lies in the upper central part of the abdomen behind the lower ribs. Although it is a single organ, several different parts of the stomach exist: the fundus, body, antrum and pylorus. Food passes through the pylorus and into the duodenum where further digestion occurs. An internal image of a healthy stomach. The stomach wall is composed of four layers. The inner lining (mucosa) consists of millions of microscopic glands which secrete gastric juices. Beneath this is a supporting layer (submucosa) and beneath this is the muscle layer. This is responsible for stomach contractions and emptying. Finally there is a thin outer covering known as the serosa. The stomach and duodenum have a rich blood supply, derived from the aorta (the main artery in the body) and are also supplied by nerves from the spinal cord.

An iillustration of the stomach and its layers. Function and Control The stomach carries out several different functions. It acts as the major store for food during a meal and can hold up to 1.5 litres of food and fluid. Special cells (parietal cells) in the glands of the inner lining of the stomach secrete powerful hydrochloric acid that help break down food in the stomach. Other special cells release protein-digesting enzymes (pepsinogens) which become active in the acid environment and begin digesting protein. The stomach secretes a number of other important substances including hormones to regulate the functions of the stomach, mucus to protect the gastric lining from damage by acid, and a substance (intrinsic factor) which is necessary for the body to absorb vitamin B12 from the diet. An internal image of a healthy duodenum. Coordinated contractions of the stomach are important for grinding and mixing ingested food with the gastric secretions. This ensures good mixing of stomach contents and also helps to filter out partially digested food to prevent large pieces from entering the duodenum. Lastly, partially digested food and liquids are carefully emptied from the stomach, through the pylorus, into the duodenum.

These processes of secreting gastric juices, mixing food and gastric emptying are normally carefully regulated and involve the coordinated action of hormones, nerves, and muscles. Once food enters the duodenum, its acidity is neutralized by mixing with alkaline juices from the pancreas and bile in preparation for further digestion and absorption lower down the small intestine. Dysfunction Disorders of the stomach and the duodenum are extremely common and a considerable source of suffering in the population. Upper abdominal pain , indigestion and heartburn may affect up to 25% of the population each year and these symptoms cause suffering, fear about serious disease, time off work and reduced quality of life. Problems may arise from a number of different mechanisms and lead to a variety of symptoms. The integrity of the inner lining (mucosa) of the stomach depends on a careful balance between the "aggressive" factors (such as acid) which tend to damage the lining and "defensive" factors (such as mucus) which help to protect the delicate surface lining. Disruption of this balance caused by too much acid (or weakened defense) can result in erosions or ulcers with symptoms including upper abdominal pain, indigestion or heartburn, nausea and/or vomiting.

In other patients, symptoms may result from problems with stomach emptying. This can either be the result of a physical blockage (i.e. scarring from an ulcer or a malignant tumor at the pylorus) or else it can result from abnormal control of stomach emptying (known as gastroparesis ). Symptoms include abdominal pain, bloating , nausea, vomiting after meals, lack of appetite and early satiety (inability to eat a full meal or feeling full after only a small amount of food). Erosions, ulcers and tumors may cause bleeding. If the bleeding is brisk and of sufficient quantity it may result in vomiting of bright red blood ( hematemesis ). Blood which has been in the stomach for any length of time undergoes partial digestion and turns black in color. This leads to vomiting of black fluid ("coffee grounds") or the passage of sticky black stools (melena) as the blood passes down through the digestive tract. A small percentage of ulcers and other abnormalities in the stomach bleed very slowly over a long time and the patient is unaware of the bleeding. Eventually the body's iron stores run out and anemia develops. Gastrointestinal bleeding is discussed further below.

Ulcers, tumors and other stomach problems may all produce very similar symptoms and it is not possible to determine the cause from symptoms alone. Patients with persistent or worrying symptoms require investigation, usually by endoscopy , to make a diagnosis and select appropriate treatment. Health Maintenance Diet Diet is believed to be important in the development of upper abdominal symptoms but there is little scientific evidence to incriminate individual foods or dietary components in causing particular symptoms. There is no specific diet which is known either to predispose to (or protect against) the development of peptic ulcers . In general, a sensible, balanced and healthy diet is recommended but people should avoid foods which they feel clearly upset their stomachs or provoke symptoms. Regular, unhurried meals are also important. Smoking Smoking is an important factor in causing disorders of the stomach and duodenum. Tobacco contains compounds which increases acid production, impair production of protective mucus and damage the lining of the stomach, thereby predisposing to erosion and ulcers. Excess alcohol intake, especially spirits or hard liquor, irritates the gastric lining and may also play a role in causing gastritis , ulcers, and gastric cancer . A variety of medications may cause problems in the stomach and duodenum.

Aspirin and other anti-inflammatory drugs (non-steroidal anti-inflammatory drugs, NSAID's) used to treat muscular and arthritic pain, commonly damage the stomach lining and cause erosions, ulcers and bleeding from the stomach and duodenum. Other medications interfere with gastric emptying and cause nausea, bloating or vomiting. If you suffer from problems with your stomach, you should always consult your doctor before taking any new medications. The role of psychological stress in the development of symptoms of indigestion and peptic ulcer disease is not clear. Periods of stress can make most medical conditions worse but whether stress specifically predisposes people to the development of peptic ulcers is not clear at present. Related Pages

Question: In human anatomy, what is the first part of the intestine, located immediately beyond the stomach?
Answer: Duodenum