cloacal membrane


clo·a·cal mem·brane

a transitory membrane in the caudal area of the embryo, separating the proctodeum from the cloaca; it is divided into anal and genitourinary membranes that break down during the eighth to ninth week of human development to establish the external opening for the alimentary and genitourinary tracts.

clo·a·cal mem·brane

(klō-ā'kăl mem'brān) A transitory membrane in the caudal area of the ventral wall of the embryo, separating the endodermal from the ectodermal cloaca; it is divided into anal and genitourinary membranes that break down during the eighth to ninth weeks to establish the external opening for the alimentary and genitourinary tracts.