Left colic artery
Arteria colica sinistra
The highest offshoot of the inferior mesenteric artery, running left behind the peritoneum to supply the descending colon and left colic flexure.
At a glance
- English
- Left colic artery
- Latin (TA2)
- Arteria colica sinistra
- System
- Artery
- Region
- Trunk
- Side
- Single, on the midline
About the left colic artery
The left colic artery is normally the first and highest vessel to leave the inferior mesenteric artery. It springs from the left side of its parent soon after that vessel leaves the aorta and then heads to the left, lying behind the peritoneum of the posterior abdominal wall on psoas major.
During this course it, or its branches, passes in front of the left ureter and the left gonadal vessels, and it lies close to the inferior mesenteric vein. After a short but variable distance it divides into two. The ascending branch climbs across the front of the left kidney towards the left colic (splenic) flexure, passes between the layers of the transverse mesocolon and joins the left branch of the middle colic artery, while the descending branch runs down to meet the highest sigmoid artery.
These joins create arches close to the bowel, and from them straight vessels pass into the wall of the descending colon, as well as the left end of the transverse colon. The arches form part of the marginal artery, the channel that runs round the whole colon and links the superior and inferior mesenteric territories. Near the left colic flexure this link is thinnest, which is why this part of the colon is vulnerable when blood flow falls; in some people a more central channel between the left colic and middle colic arteries also connects the two systems.
In operations for cancer of the rectum and sigmoid colon, surgeons choose whether to tie the inferior mesenteric artery at its root or to keep the left colic artery and divide the vessel below it. Keeping the left colic artery may give the remaining colon a better blood supply, and outcomes may be poorer when it is tied. The ureter and gonadal vessels must be protected while the artery is being freed.
Course and supply
- Arises from
- The inferior mesenteric artery's first branch, leaving its left side.
- Ends in
- Divides into an ascending branch that joins the middle colic artery near the left colic flexure and a descending branch that joins the highest sigmoid artery.
- Supplies
- Supplies the descending colon, the left colic flexure and the left end of the transverse colon.
Anthromica
See the left colic 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.
