Jejunal and ileal arteries
Branch
Twelve to fifteen branches from the left side of the SMA fanning out in the mesentery. They form anastomotic arcades — few large loops with long vasa recta in the jejunum, many short tiers with short vasa recta in the ileum — and are the only supply of the jejunum and ileum.
Traced from the start
- Abdominal aorta
- Superior mesenteric artery
- Jejunal and ileal arteries
Detail
- Supplies
- Jejunum and ileum (terminal ileum shared with the ileocolic)
- Number
- 12–15 from the left (convex) side of the SMA
- Arcades
- Jejunum: 1–2 tiers, long vasa recta; ileum: 4–5 tiers, short vasa recta
When it goes wrong
Adhesive band or volvulus twists the mesentery around its pedicle
Strangulated obstruction: venous congestion then arterial occlusion — pain becomes constant, peritonism, fever and raised lactate
Atherosclerotic thrombosis at the SMA origin (as opposed to an embolus lodging distally)
Whole midgut infarcts including proximal jejunum and right colon; often preceded by months of postprandial pain
Practise this structure
1 question in the bank tagged Small Bowel.