Rectal Arteries, Posterior View

Description

Posteriorly oriented, the distal sigmoid colon transitions inferiorly into the rectum and upper anal canal, with the superior rectal artery descending in the mesorectum as the terminal continuation of the inferior mesenteric artery. Paired lateral contributions from the internal iliac system are implied as middle rectal arteries approaching the rectal wall from the right and left pelvic sidewalls, while inferior rectal arteries typically arise more distally from the internal pudendal arteries and course medially toward the anal canal. Epiploic appendages cluster along the sigmoid colon, and the rectum sits midline, anterior to the sacrum and coccyx. Vessel caliber tapers from proximal to distal. Fast. Rectal arterial anatomy matters because the rectum sits at a watershed between hindgut and pelvic vascular territories, and those anastomoses influence bleeding patterns, ischemic risk, and oncologic resection planes. In low anterior resection or total mesorectal excision, ligation level at the inferior mesenteric artery and handling of the superior rectal artery affect perfusion of the rectal stump and can contribute to anastomotic leak when collateral flow is limited. Hemorrhoidal disease also maps onto this arterial supply, with internal hemorrhoids classically associated with the superior rectal circulation above the pectinate line and external hemorrhoids relating to the inferior rectal supply, a distinction that guides office procedures versus operative approaches. Ideal for colorectal surgery teaching files, pelvic anatomy lab manuals, and GI or anatomy course lectures covering the sigmoid colon, rectum, and hindgut vascular supply from the inferior mesenteric artery and internal iliac branches. Publishers can also place it alongside chapters on diverticular disease, rectal cancer staging, or anorectal bleeding to anchor the discussion in clear posterior spatial relationships. Anatomical accuracy verified by SciePro's Medical Advisory Board.