proctodeum /proktō″dē·əm/ pl. proctodea [Gk, proktos + hodiaos, a route] , a depression of the ectoderm, behind the urorectal septum of the developing embryo, that forms the anus and anal canal when the cloacal membrane ruptures. Also spelled proctodaeum. Compare stomodeum. −proctodeal, proctodaeal, adj.
