Pudendal nerve: Wikis

  

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Nerve: Pudendal nerve
Pudendal nerve.svg
Pudendal nerve, course and branches
Gray837.png
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

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

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.

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.

Additional images

See also

Neurogenic bladder

References

  1. ^ Mellion MB (January 1991). "Common cycling injuries. Management and prevention". Sports Med 11 (1): 52–70. doi:10.2165/00007256-199111010-00004. PMID 2011683.  

External links








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