middle rectal veins
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mid·dle rec·tal veins[TA]
several veins that pass from the rectal venous plexus (in which they anastomose with the superior rectal veins) to the internal iliac vein, which ultimately drains into the inferior vena cava. Given that the superior rectal veins ultimately drain into the portal vein, the middle retal veins participate in a portocaval anastomosis, and the rectal venous plexus is subject to varicosities (hemorrhoids) although they commonly occur in the absence of portal hypertension.
Synonym(s): venae rectales mediae [TA]