Pudendal nerve
Nervus pudendus
NervousNervesPelvisLeft and right
View left in 3D View right in 3D
- What it is
- Arises from S2-S4, leaves the pelvis through the greater sciatic foramen, hooks around the sacrospinous ligament at the ischial spine, re-enters through the lesser sciatic foramen and runs forward in the pudendal (Alcock) canal on the wall of the ischioanal fossa, giving the inferior rectal, perineal and dorsal penile nerves.
- Function
- Motor to the external anal and urethral sphincters and the perineal muscles; sensation from the anus, perineum and external genitalia - the nerve of continence and sexual sensation.
- Size
- About 3 mm thick; ~15 cm long
- Clinical note
- A pudendal block at the ischial spine is used in childbirth and perineal repairs; long-distance cyclists can compress it on the saddle, causing genital numbness.