noun
valve of the veins; venous valve
Anatomical term for the valves inside veins that prevent backflow of blood.
血管弁膜は血液の逆流を防ぐ役割を果たしている。
Venous valves play a role in preventing the backflow of blood.
弁膜 is a general term for any membranous valve in the body, while 血管弁膜 specifically refers to valves in blood vessels.
Compound of 血管 (blood vessel) + 弁膜 (valve, membranous flap). The exact historical derivation is uncertain, but the term is a straightforward medical compound.