Muscles located beneath the bulbocavernosus muscles on both sides of the vaginal opening.
One of the two sacculated collections of veins, lying on either side of the vagina beneath the bulbocavernosus muscle, connected anteriorly by the pars intermedia, and through this strip of cavernous tissue communicating with the erectile tissue of the clitoris. The vestibular bulbs are the homologues of the male corpus spongiosum. Injury during labor may give rise to troublesome bleeding.