What Is the Superior Mesenteric Artery?

The superior mesenteric artery starts at the height of the first lumbar spine from the anterior wall of the abdominal aorta, descends behind the splenic vein and the head of the pancreas, crosses the anterior process of the pancreatic axillary process, and enters the small intestinal mesentery between the lower edge of the pancreas and the level of the duodenum Root, obliquely downward to the right, to the end of the right popliteal fossa, and its anastomosis with the ileal branch of the ileocolic artery. The trunk of the superior mesenteric artery is slightly arched to the left, and the pancreaticoduodenal artery and more than ten branches of the ileum and ileum are emitted in sequence from the convex side of the arch, and the middle colon artery and right colon are issued in sequence from the concave side of the arch. Arteries and ileocolic arteries.

The superior mesenteric artery starts at the height of the first lumbar spine from the anterior wall of the abdominal aorta, descends behind the spleen vein and the head of the pancreas, crosses the anterior process of the pancreatic axillary process, and enters the small intestinal mesentery between the lower edge of the pancreas and the level of the duodenum Root, obliquely downward to the right, to the end of the right popliteal fossa, and its anastomosis with the ileal branch of the ileocolic artery. The trunk of the superior mesenteric artery is slightly arched to the left, and the pancreaticoduodenal artery and more than ten branches of the ileum and ileum are emitted in sequence from the convex side of the arch, and the middle colon artery and right colon are issued in sequence from the concave side of the arch. Arteries and ileocolic arteries.

Chinese name

Superior mesenteric artery

Foreign name

superior mesenteric artery

Trunk

Arched slightly to the left

Classification

Inferior pancreaticoduodenal artery, jejunum ileum, etc.

Anatomy of the superior mesenteric artery:

Slightly below the celiac artery, it originates from the anterior wall of the abdominal aorta, enters the double-layer peritoneum of the small intestinal mesentery root behind the pancreas, and continues obliquely down to the right popliteal fossa, whose end coincides with the ileocolic artery. The superior mesenteric artery sends out more than a dozen intestinal arteries to the left along the way, and the inferior pancreaticoduodenal arteries, middle colon arteries, right colon arteries, and ileocolic arteries from the top to the right, which are distributed in the duodenum, The right half of the pancreatic head, jejunum, ileum, cecum, appendix, ascending colon, and transverse colon form anastomosis with each other.

The intestinal arteries are generally 12-16, and they are located in the small intestine. Each intestine artery is divided into two branches. The adjacent branches kiss each other to form a first-level arterial arch, and then branch out from the arch to form a second-level arch. Up to five anastomotic bows. A number of vertical small arteries, called straight arteries, emerge from the last-stage arterial arch and enter the wall of the small intestine through the mesentery. The anastomosis between the straight arteries is not sufficient, so if the straight arteries are damaged, the section of intestine it nutritionally can cause ischemic necrosis. Therefore, when intestinal resection is needed, the complete arterial arch and straight artery should be kept as far as possible to ensure blood supply to the intestinal stump. The upper mesenteric artery has a curved stroke, and the intestinal artery forms a multi-stage arterial arch to meet and facilitate the needs of small bowel functional activities.

Physiological location of the superior mesenteric artery:

One of the visceral branches of the abdominal aorta. This artery starts from the abdominal aorta just below the celiac artery. After it is sent out, it enters the mesenteric root between the pancreas and duodenum, and emits the inferior pancreaticoduodenal, intestinal, ileocolic, and right colon , Middle colonic artery and so on. The organs of the superior mesenteric artery are the intestines from the pancreas and below the duodenum to the middle of the transverse colon. This artery coincides with the branch of the duodenum and celiac artery; it anastomates with the branch of the inferior mesenteric artery in the middle of the transverse colon; if this artery is embolized, serious consequences can occur.

Structure of superior mesenteric artery:

Inferior pancreaticoduodenal artery

The inferior pancreaticoduodenal arteries are small, and they pass through the superior mesenteric vein to the upper right, divided into anterior and posterior branches, which respectively anastomize the superior anterior and posterior superior pancreaticoduodenal arteries. This artery sometimes starts from the first jejunal artery.

Jejunum and ileum artery

From the convex side of the superior mesenteric artery, about 12-16 branches, traveling in the mesentery. The upper distribution in the jejunum is called the jejunalarteries; the lower distribution in the ileum is called the ileal artery ilealarteries. Each vein is divided into two ascending and descending branches that coincide with the ascending and descending branches of the adjacent intestinal artery to form a first-order moving arch. . The branches of the arterial arch kiss to form a secondary arch, which in turn can form a third, fourth, and fifth arch. Many small straight (tubular) arteries are emitted from the last-stage arterial arch and enter the small intestine wall from the mesentery edge of the small intestine, but there is very little anastomosis between these arteries, especially the small intestinal mesentery has poor blood flow. Generally there is only one level of arterial arch in the proximal part of the jejunum. Later, the number of arterial arches gradually increases, reaching up to 4-5 levels to the end of the jejunum and the proximal portion of the ileum, but it is reduced to 1-2 levels to the end of the ileum. Those with straight (tube) arterial jejunum are long and thick, while those with ileum are short and small.

Middle colon artery

The middle colonic artery starts at the inferior side of the head of the pancreas from the concave side of the superior mesenteric artery, then enters the mesentery of the transverse colon, and travels to the right and forward; The right branch line goes up to the right to the right curve of the colon and coincides with the ascending branch of the right colon artery; the left branch runs left and coincides with the ascending branch of the left colon artery, called the Riolan artery arch. The left and right branches emit small branches distributed in the transverse colon during the stroke.

Right colon artery

It starts from the superior mesenteric vein below the starting point of the middle colonic artery, or coexists with the middle colonic artery, and runs right through the deep peritoneum of the posterior abdominal wall. The ascending branch ascends to the right branch of the middle colonic vein; the descending branch ascends to the superior trunk of the ileocolic artery. The arterial branch is distributed in 2/3 of the ascending colon and the right bowel of the colon.

Ileocolic artery

The ileocolic artery of the ileocolic arteries is the lowest branch of the concave side of the superior mesenteric artery, and it descends to the right and obliquely on the deep side of the posterior wall of the abdominal wall. The upper trunk coincides with the descending branch of the right colon artery; the lower trunk anastomizes with the end of the superior mesenteric artery to form an arch.