Arterial arcades | |
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Loop of small intestine showing distribution of intestinal arteries | |
Anatomical terminology |
The arterial arcades (intermesenteric arterial anastomoses or Riolan arcades [1] ) are a series of anastomosing arterial arches between the arterial branches of the jejunum and ileum.
The jejunum is the second part of the small intestine in humans and most higher vertebrates, including mammals, reptiles, and birds. Its lining is specialized for the absorption by enterocytes of small nutrient molecules which have been previously digested by enzymes in the duodenum.
The ileum is the final 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 posterior intestine or distal intestine may be used instead of ileum. Its main function is to absorb vitamin B12, bile salts, and whatever products of digestion were not absorbed by the jejunum.
Nearest the duodenum the mesenteric loops are primary, the vasa recta are long and regular in distribution, and the translucent spaces (lunettes) are extensive.
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.
For the kidney structure, see straight arterioles of kidney
Toward the ileocolic junction, secondary and tertiary loops are observed, the vessels are smaller and become obscured by numerous fat-tabs.
The diagrams below show the arrangement and variations of the loops of the mesenteric vessels for various segments of the small intestine of average length:
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 intestinal arteries arise from the convex side of the superior mesenteric artery. They are usually from twelve to fifteen in number, and are distributed to the jejunum and ileum.
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 left colic flexure to the upper part of the rectum, which includes the descending colon, the sigmoid colon, and part of the rectum. Proximally, its territory of distribution overlaps with the middle colic artery, and therefore the superior mesenteric artery. The SMA and IMA anastomose via the marginal artery of the colon and via Riolan's arcade. The territory of distribution of the IMA is more or less equivalent to the embryonic hindgut.
In anatomy, the gastroduodenal artery is a small blood vessel in the abdomen. It supplies blood directly to the pylorus and proximal part of the duodenum, and indirectly to the pancreatic head.
The superior mesenteric vein is a blood vessel that drains blood from the small intestine. At its termination 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.
The splenic vein is a blood vessel that drains blood from the spleen, the stomach fundus and part of the pancreas. It is part of the hepatic portal system.
In human anatomy, the marginal artery of the colon, also known as the marginal artery of Drummond and artery of Drummond is an artery that connects the inferior mesenteric artery with the superior mesenteric artery. It is sometimes absent, as an anatomical variant.
In human anatomy, inferior epigastric artery refers to the artery that arises from the external iliac artery and anastomoses with the superior epigastric artery. Along its course, it is accompanied by a similarly named vein, the inferior epigastric vein. These epigastric vessels form the lateral border of Hesselbach's triangle, which outlines the area through which direct inguinal hernias protrude.
The lingual artery arises from the external carotid between the superior thyroid artery and facial artery. It can be located easily in the tongue.
The middle rectal artery is an artery in the pelvis that supplies blood to the rectum.
The right gastroepiploic artery is one of the two terminal branches of the gastroduodenal artery. It runs from right to left along the greater curvature of the stomach, between the layers of the greater omentum, anastomosing with the left gastroepiploic artery, a branch of the splenic artery.
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 right colic artery arises from about the middle of the concavity of the superior mesenteric artery, or from a stem common to it and the ileocolic.
The middle colic artery is a branch of the superior mesenteric artery that mostly supplies the transverse colon. It arises just below the pancreas. It passes inferiorly and anteriorly between the layers of the transverse mesocolon, and divides into left and right branches. The right branch anastomoses with the right colic artery, and the left anastomoses with the left colic artery, a branch of the inferior mesenteric artery. This sequence of anastomses are frequently referred to as the marginal artery of the colon.
The left colic artery is a branch of the inferior mesenteric artery that runs to the left behind the peritoneum and in front of the psoas major muscle, and after a short, but variable, course divides into an ascending and a descending branch; the stem of the artery or its branches cross the left ureter and left internal spermatic vessels.
The middle suprarenal arteries are two small vessels which arise, one from either side of the abdominal aorta, opposite the superior mesenteric artery.
The ileocolic artery is the lowest branch arising from the concavity of the superior mesenteric artery.
The superior rectal artery is an artery that descends into the pelvis to supply blood to the rectum.
The pancreatic branches or pancreatic arteries are numerous small vessels derived from the splenic artery as it runs behind the upper border of the pancreas, supplying its body and tail.
This article incorporates text in the public domain from page 1175 of the 20th edition of Gray's Anatomy (1918)
The public domain consists of all the creative work to which no exclusive intellectual property rights apply. Those rights may have expired, been forfeited, expressly waived, or may be inapplicable.
Gray's Anatomy is an English language textbook of human anatomy originally written by Henry Gray and illustrated by Henry Vandyke Carter. Earlier editions were called Anatomy: Descriptive and Surgical, Anatomy of the Human Body and Gray's Anatomy: Descriptive and Applied, but the book's name is commonly shortened to, and later editions are titled, Gray's Anatomy. The book is widely regarded as an extremely influential work on the subject, and has continued to be revised and republished from its initial publication in 1858 to the present day. The latest edition of the book, the 41st, was published in September 2015.
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