constrictor vulvae muscle NCIT:C52898 constrictor vulvae UMLS:C1707495 UBERON:0011387 MA:0002281 The constrictor muscle of the labia is weakly developed in the female dog which blends dorsally with the external anal sphincter muscle and attaches to the coccygeal fascia at the level of the first and second coccygeal vertebrae. It encircles the vulva and vestibule for a distance of about 1 cm. caudal to the area where the urethra enters the vestibule. Its action is to lift the labia dorsally to facilitate intromission of the penis into the vagina. The constrictor vestibuli and vulvae are homologous to the bulbospogiosus (bulbocavernosus) muscle in the male. sphincter vaginae SCTID:244961006 EMAPA:37483 bulbospongiosus muscle