The pudendal nerve (S2, S3, S4) provides the predominant sensory and motor innervation to the perineum. Which canal does it traverse to reach the perineum?

• A Obturator canal
• B Femoral canal
• C The nerve travels directly through the levator ani
• D Pudendal (Alcock's) canal in the lateral wall of the ischiorectal fossa ✓

Explanation

After exiting the greater sciatic foramen below the piriformis, the pudendal nerve loops around the sacrospinous ligament and ischial spine, then re-enters the pelvis through the lesser sciatic foramen to travel in the pudendal (Alcock's) canal — a fascial canal formed within the obturator fascia on the lateral wall of the ischiorectal (ischioanal) fossa. A pudendal nerve block is performed at the ischial spine. The obturator canal transmits the obturator nerve and vessels.

Reference: BD Chaurasia's Human Anatomy, 8th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.