APPLIED RADIOLOGICAL ANATOMY

Detailed explanation-1: -The pudendal nerve (S2-S4) is a mixed nerve mainly in charge of the sensory and motor supply of the perineum and external genitalia in both sexes. The nerve arises in the pelvic cavity from the sacral plexus, more specifically from the anterior rami of spinal nerves S2, S3 and S4.

Detailed explanation-2: -The pudendal nerve: Connects to the S2 to S4 sacral spinal nerve roots in the sacral plexus. Runs through your pelvis and gluteal (buttock) region at the upper end of the thighbone (femur). Passes through an opening in the pelvic bone called the greater sciatic foramen.

Detailed explanation-3: -The perineal branch of S4 is a mixed motor and sensory nerve from the sacral plexus and should not be confused with the perineal branch of the pudendal nerve.

Detailed explanation-4: -A pudendal nerve block aims to block the nerve as it enters the lesser sciatic foramen, 1 cm inferior and medial relative to the attachment of the sacrospinous ligament to the ischial spine. Different anatomical approaches are utilized to achieve successful pudendal nerve blocks. They may be unilateral or bilateral.