The Pudendal Nerve (n. pudendus; internal pudic nerve) derives its fibers from the ventral branches of the second, third, and fourth sacral nerves.
It passes between the Piriformis and Coccygeus muscles and leaves the pelvis through the lower part of the greater sciatic foramen. It then crosses the spine of the ischium, and reënters the pelvis through the lesser sciatic foramen. It accompanies the internal pudendal vessels upward and forward along the lateral wall of the ischiorectal fossa, being contained in a sheath of the obturator fascia termed Alcock’s canal, and divides into two terminal branches, viz., the perineal nerve, and the dorsal nerve of the penis or clitoris. Before its division it gives off the inferior hemorrhoidal nerve.