The mesenteric arteries take blood from the aorta and distribute it to a large portion of the gastrointestinal tract.
Both the superior and inferior mesenteric arteries arise from the abdominal aorta. [1] Each of these arteries travel through the mesentery, within which they branch several times before reaching the gut. In humans, many of these branches are named, but in smaller animals the branches are more variable. In some animals, including humans, branches of these arteries join with the marginal artery of the colon, which means that occlusion of one of the main arteries does not necessarily lead to the death of the part of the gut that it usually supplies.
The term mesenteric artery is also used to describe smaller branches of these vessels which, particularly in smaller animals, provide a significant source of vascular resistance. These branches have a dense innervation by sympathetic nerves, allowing the brain to control their diameter and hence the resistance to blood flow to the gut. This is of particular importance when blood flow is required elsewhere, such as in exercise or shock, where a large proportion of the blood is required to supply the needs of skeletal muscle; by constricting the smaller mesenteric vessels, the resistance of blood flow to the gut increases, and hence blood flows more readily to other organs. [2]
The aorta is the main and largest artery in the human body, originating from the left ventricle of the heart and extending down to the abdomen, where it splits into two smaller arteries. The aorta distributes oxygenated blood to all parts of the body through the systemic circulation.
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The duodenum is the first section of the small intestine in most higher vertebrates, including mammals, reptiles, and birds. In fish, the divisions of the small intestine are not as clear, and the terms anterior intestine or proximal intestine may be used instead of duodenum. In mammals the duodenum may be the principal site for iron absorption. The duodenum precedes the jejunum and ileum and is the shortest part of the small intestine.
The small intestine or small bowel is an organ in the gastrointestinal tract where most of the end absorption of nutrients and minerals from food takes place. It lies between the stomach and large intestine, and receives bile and pancreatic juice through the pancreatic duct to aid in digestion.The small intestine is about 20 feet long and folds many times to fit in the abdomen. Although it is longer than the large intestine, it is called the small intestine because it is smaller in width.
The abdominal aorta is the largest artery in the abdominal cavity. As part of the aorta, it is a direct continuation of the descending aorta.
The renal arteries are paired arteries that supply the kidneys with blood. Each is directed across the crus of the diaphragm, so as to form nearly a right angle.
The coeliacartery, also known as the coeliac trunk, or truncus coeliacus, is the first major branch of the abdominal aorta. It is about 1.25 cm in length. Branching from the aorta at thoracic vertebra 12 (T12) in humans, it is one of three anterior/ midline branches of the abdominal aorta.
In human anatomy, the superior mesenteric artery (SMA) arises from the anterior surface of the abdominal aorta, just inferior to the origin of the celiac trunk, and supplies the intestine from the lower part of the duodenum through two-thirds of the transverse colon, as well as the pancreas.
In human anatomy, the inferior mesenteric artery, often abbreviated as IMA, is the third main branch of the abdominal aorta and arises at the level of L3, supplying the large intestine from the distal transverse colon to the upper part of the anal canal. The regions supplied by the IMA are the descending colon, the sigmoid colon, and part of the rectum.
The superior mesenteric vein is a blood vessel that drains blood from the small intestine. Behind the neck of the pancreas, the superior mesenteric vein combines with the splenic vein to form the hepatic portal vein. The superior mesenteric vein lies to the right of the similarly named artery, the superior mesenteric artery, which originates from the abdominal aorta.
In human anatomy, the marginal artery of the colon, also known as the marginal artery of Drummond, the artery of Drummond, and simply as the marginal artery, is an artery that connects the inferior mesenteric artery with the superior mesenteric artery. It is sometimes absent, as an anatomical variant.
The internal iliac artery is the main artery of the pelvis.
Ischemic colitis is a medical condition in which inflammation and injury of the large intestine result from inadequate blood supply. Although uncommon in the general population, ischemic colitis occurs with greater frequency in the elderly, and is the most common form of bowel ischemia. Causes of the reduced blood flow can include changes in the systemic circulation or local factors such as constriction of blood vessels or a blood clot. In most cases, no specific cause can be identified.
In human anatomy, the hepatic portal system is the system of veins comprising the hepatic portal vein and its tributaries. It is also called the portal venous system and splanchnic veins, which is not synonymous with hepatic portal system and is imprecise.
The sigmoid arteries, two or three in number, run obliquely downward and to the left behind the peritoneum and in front of the psoas major, ureter, and internal spermatic vessels. They originate from the inferior mesenteric artery branch of the abdominal aorta.
The middle suprarenal arteries are two small vessels which arise, one from either side of the abdominal aorta, opposite the superior mesenteric artery.
An acute abdomen refers to a sudden, severe abdominal pain. It is in many cases a medical emergency, requiring urgent and specific diagnosis. Several causes need immediate surgical treatment.
The superior rectal artery is an artery that descends into the pelvis to supply blood to the rectum.
The intercostal arteries are a group of arteries that supply the area between the ribs ("costae"), called the intercostal space. The highest intercostal artery is an artery in the human body that usually gives rise to the first and second posterior intercostal arteries, which supply blood to their corresponding intercostal space. It usually arises from the costocervical trunk, which is a branch of the subclavian artery. Some anatomists may contend that there is no supreme intercostal artery, only a supreme intercostal vein.
The superior mesenteric vessels are composed of the superior mesenteric artery and the superior mesenteric vein.