Pudendal nerve is a branch of the sacral plexus that innervates the external anal sphincter and other perineal structures.
After originating in the sacral plexus, the pudendal nerve leaves the main pelvic cavity by passing through the greater sciatic foramen into the gluteal region. After a brief course in the gluteal region, the nerve enters the perineum through the lesser sciatic foramen. It then passes forward in the pudendal canal and by means of its branches, supplies the external anal sphincter and other structures of perineum.
Pudendal nerve has following branches;
- Inferior rectal nerve: It runs medially across the ischiorectal fossa and supplies the external anal sphincter, mucosa of the lower half of anal canal and perianal skin.
- Dorsal nerve of penis (or clitoris in females): This branch is distributed to the penis in males and clitoris in females.
- Perineal nerve: It supplies the muscles of the urogenital triangle and the skin on the posterior surface of the scrotum (in males) or labium majus (in females).