Marginal artery
Arteria marginalis coli
A continuous arterial channel along the inner border of the colon, linking the colic branches of both mesenteric arteries.
At a glance
- English
- Marginal artery
- Latin (TA2)
- Arteria marginalis coli
- System
- Artery
- Region
- Trunk
- Side
- Single, on the midline
About the marginal artery
The marginal artery of the colon, also called the marginal artery of Drummond, is not a branch with a single origin. It is a chain of anastomoses formed where the colic arteries meet one another close to the mesenteric border of the large intestine. It runs from the ileocaecal region, around the ascending, transverse and descending colon, to the sigmoid colon; texts differ on whether it continues into the superior rectal artery.
On the right it is built from the ileocolic, right colic and middle colic arteries of the superior mesenteric artery. On the left it is continued by the left colic and sigmoid arteries of the inferior mesenteric artery. Each of these colic vessels divides into branches that join their neighbours, and the outermost line of these junctions forms the marginal artery. From it, short straight arteries (vasa recta) pass to the bowel wall, where they encircle the colon and supply its layers.
The channel joins the two mesenteric territories and allows blood to reach a part of the colon even when its own main vessel is blocked or tied. This is why the inferior mesenteric artery can be ligated in aortic surgery or in removal of the rectum and sigmoid colon without the descending colon losing its supply, provided the marginal artery is intact.
The chain is not equally strong everywhere. At the splenic flexure, where the middle colic and left colic territories meet, and at the junction of sigmoid and rectum, it may be thin or broken. These watershed zones are the commonest sites of ischaemic colitis, and the surgeon checks the pulse in the marginal artery before joining two ends of bowel.
Course and supply
- Arises from
- Formed by the joining of the ileocolic, right colic and middle colic branches of the superior mesenteric artery with the left colic and sigmoid branches of the inferior mesenteric artery.
- Ends in
- Gives the straight arteries (vasa recta) that enter the wall of the colon along its whole length.
- Supplies
- Supplies the colon wall through its vasa recta and links the superior and inferior mesenteric territories as a collateral route.
Anthromica
See the marginal artery where it really sits, with every layer of the body around it.
- Every layer, one body. Peel from muscle to bone, nerve, vessel and organ, and turn it any way.
- English and Latin. Every structure named the way your exam names it.
- Quiz until it sticks. Short drills on the structures you keep missing.
Free to start. No card.
