This section is from the book "Anatomy Of The Arteries Of The Human Body", by John Hatch Power. Also available from Amazon: Anatomy of the Arteries of the Human Body, with the Descriptive Anatomy of the Heart.
The Colica Dextra passes towards the right colon, near which it divides into—a superior branch, which anastomoses with the right branch of the colica media; and an inferior branch, which descends to anastomose with the superior branch of the ileo-colic artery: it supplies the ascending colon.
The lleo- Colic branch appears to be the termination of the superior mesenteric; it runs downwards, and to the right side, towards the caecum. Before it reaches the intestine, however, it divides into three branches,—the superior of which ascends to anastomose with the colica dextra; the inferior descends to anastomose with the terminating branches from the convexity of the superior mesenteric artery; while the middle branch passes behind the caecum, and terminates in supplying the ileum, caecum, and vermiform appendix.
In the foetus, the superior mesenteric artery gives off an omphalo-mescnteric branch, which proceeds along the umbilical cord to be lost on the vesicula umbilicalis. It is usually obliterated at the end of the second month, but Cruveilhier saw it in an acephalous foetus at the ninth month.
The Inferior Mesenteric Artery, smaller than the preceding, arises from the anterior and left part of the aorta, about an inch and a half above its bifurcation. It first descends on the aorta, between the layers of the mesocolon, and then turns over the left common iliac artery to terminate behind the rectum. This terminating branch is called the superior haemorrhoidal. In the above course, the inferior mesenteric artery forms an arch, the convexity of which looks to the left side. Its branches are three in number:—