Deep branch of the perineal nerve

The deep branch of the perineal nerve (or muscular branches) are distributed to the muscles of the perineum. These include the superficial transverse perineal muscle, bulbocavernous, ischiocavernosus, and constrictor urethræ.

A branch, the nerve to the bulb, given off from the nerve to the bulbocavernosus, pierces this muscle, and supplies the corpus cavernosum, ending in the mucous membrane of the urethra.