Nerve · Pelvis

Perineal nerve

Nervi perineales

The larger of the pudendal nerve's two terminal branches, running forward below the internal pudendal artery to serve the front half of the perineum. It divides in two: a superficial part that continues as the posterior scrotal or labial nerves to supply that skin, and a deep part that turns inward to supply the muscles of the urogenital triangle — the transverse perineal muscles, the muscles wrapped around the erectile tissue, and the external urethral sphincter. It is therefore the nerve behind voluntary control of urination, and it does that job from below, in the perineum, rather than from inside the pelvis.