Pudendal nerve
From Wikipedia, the free encyclopedia
| Nerve: Pudendal nerve | |
|---|---|
 |
|
| Pudendal nerve, course and branches | |
 |
|
| Sacral plexus of the right side. (Inferior pudendal labeled at bottom right.) | |
| Latin | nervus pudendus |
| Gray's | subject #213 967 |
| From | sacral nerves S2-S4 |
| To | inferior rectal nerves perineal nerve dorsal nerve of the penis |
The pudendal nerve is a somatic nerve in the pelvic region that innervates the external genitalia of both sexes, as well as sphincters for the bladder and the rectum. It originates in Onuf's nucleus in the sacral region of the spinal cord.
Contents |
[edit] Anatomy
The pudendal nerve originates in the sacral plexus; it derives its fibers from the ventral rami 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 rectal 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, traveling 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[1] can compress or stretch the pudendal nerve, causing temporary loss of function, but permanent injury is rare. Entrapment of the nerve is very rare but can happen. A pelvic tumor (most notably a large sacrococcygeal teratoma), or surgery to remove the tumor, can damage this nerve permanently. A pudendal nerve block is a common obstetric procedure to anesthetize the perineum during labor.
[edit] Additional images
 Dissection of side wall of pelvis showing sacral and pudendal plexuses. (Pudendal nerve labeled at center right. |
 The superficial branches of the internal pudendal artery. |
 Plan of sacral and pudendal plexuses. |
[edit] See also
[edit] References
[edit] External links
- SUNY Figs 41:04-11 - "Inferior view of female perineum, branches of the internal pudendal artery."
- Human anatomy at Dartmouth figures/chapter_32/32-2.HTM
- Human anatomy at Dartmouth figures/chapter_32/32-3.HTM
- Diagnosis and treatment options, lists of doctors and physical therapists.
- Cross section at UV pelvis/pelvis-female-17
- Diagnosis and treatment at www.nervemed.com
- www.pudendal.com
- Pudendal nerve entrapment at chronicprostatitis.com
|
||||||||||||||||||||||||||||||||||||||||||||
