Pudendal nerve

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Nerve: Pudendal nerve

Dissection of side wall of pelvis showing sacral and pudendal plexuses. (Pudendal nerve labeled at center right.)

Sacral plexus of the right side. (Inferior pudendal labeled at bottom right.)
Latin	nervus pudendus
Gray's	subject #213 967
From	sacral plexus
To	inferior rectal nerves perineal nerve dorsal nerve of the penis
Dorlands/Elsevier	n_05/12566568

The pudendal nerve is a nerve in the pelvic region that innervates the external genitalia of both sexes, as well as sphincters for the bladder and the rectum.

1 Anatomy
2 Physiology
3 Pathology
4 Additional images
5 External links

[edit] Anatomy

The pudendal nerve originates in the sacral plexus; it derives its fibers from the ventral branches of the second, third, and fourth sacral nerves (S2, S3, S4).

It passes between the piriformis and coccygeus muscles and leaves the pelvis through the lower part of the greater sciatic foramen.

It crosses the spine of the ischium, and reenters 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 the pudendal canal.

The pudendal nerve gives off the inferior anal nerves. It soon divides into two terminal branches: the perineal nerve, and the dorsal nerve of the penis (males) or the dorsal nerve of the clitoris (in females).

Branch	Description
Inferior anal nerves	given off shortly after passing through the Greater sciatic foramen.
Perineal nerve	more superficial terminal branch
Dorsal nerve of penis/Dorsal nerve of clitoris	deeper terminal branch, travelling into the deep perineal pouch

[edit] Physiology

The pudendal nerve innervates the penis and clitoris, bulbospongiosus and ischiocavernosus muscles, and areas around the scrotum, perineum, and anus. At sexual climax, the spasms in the bulbospongiosus and ischiocavernous results in ejaculation in the male and most of the feelings of orgasm in both sexes.

[edit] Pathology

Difficult childbirth or bicycling can compress or stretch the pudendal nerve but permanent injury is rare. Entrapment of the nerve is very rare but can happen. Pudendal Nerve Entrapment (PNE) is akin to Carpal Tunnel syndrome.