Middle rectal veins

Vein: Middle rectal veins
Scheme of the anastomosis of the veins of the rectum
Latin	venae rectales mediae
Gray's	subject #173 676
Drains from	rectum
Drains to	internal iliac vein
Artery	middle rectal artery

The middle rectal veins (or middle hemorrhoidal vein) take origin in the hemorrhoidal plexus and receive tributaries from the bladder, prostate, and seminal vesicle.

They run lateralward on the pelvic surface of the levator ani to end in the internal iliac vein. Veins superior to the middle rectal vein in the colon and rectum drain via the portal system to the liver. Veins inferior, and including, the middle rectal vein drain into systemic circulation and are returned to the heart, bypassing the liver.

This article was originally based on an entry from a public domain edition of Gray's Anatomy. As such, some of the information contained within it may be outdated.