rectal vein
nounMedical Definition of rectal vein
: any of three veins that receive blood from the rectal venous plexus:
a
: one draining the lower part of the rectal venous plexus and emptying into the internal pudendal vein
— called also inferior hemorrhoidal vein, inferior rectal vein
b
: one draining the bladder, prostate, and seminal vesicle by way of the middle part of the rectal venous plexus and emptying into the internal iliac vein
— called also middle hemorrhoidal vein, middle rectal vein
c
: one draining the upper part of the rectal venous plexus and forming the first part of the inferior mesenteric vein
— called also superior hemorrhoidal vein, superior rectal vein