Identify and clean the blood supply of the small intestine and colon.
- Return to the jejunum. Use blunt dissection to expose the jejunal arteries and veins by stripping away the mesentery proper. (G 4.44;N 287;Gl 16.11) Trace the jejunal arteries back to the superior mesenteric artery. Trace (and clean) the superior mesenteric artery back to the abdominal aorta. Identify the inferior pancreaticoduodenal artery. (G 4.39B;N 291;Gl 16.10) This artery is typically the first branch of the superior mesenteric artery. Trace (and clean) the distal branches of the superior mesenteric artery. Identify the ileal, ileocolic, right colic and middle colic arteries. (G 4.44;N 291;Gl 16.12) Compare and contrast the arcades and vasa recta of the jejunum and ileum.
- Identify the tributaries (jejunal, ileal, ileocolic, right colic and middle colic) of the superior mesenteric vein. (G 4.65;N 290;Gl 16.20)
- Return to the abdominal aorta. Identify the inferior mesenteric artery arising inferior to the origin of the superior mesenteric artery. (G 4.68A;N 291;Gl 16.12) Trace (and clean) the inferior mesenteric artery and its branches to the descending colon, sigmoid colon and rectum. Be careful and avoid damaging the left ureter, gonadal artery and gonadal vein. Identify the left colic, sigmoid and superior rectal arteries. Attempt to identify anastomoses between the arteries supplying the colon.
- Identify the inferior mesenteric vein and its tributaries (superior rectal, sigmoid and left colic veins). (G 4.65;N 291;Gl 16.21) Trace the inferior mesenteric vein to the splenic vein.
Important Relationships
- The superior mesenteric artery is postioned lateral (to the left) to the superior mesenteric vein and passes anterior to the duodenum (4 th part) , directly anterior to the left renal vein, and posterior to the pancreas (body).
- The superior mesenteric vein passes anterior to the duodenum (4 th part) and posterior to both the stomach (pylorus) and the pancreas (body).
