Pudendal nerve

Last edit by Alaric Steinmetz on

ICD-11: XA6WU3

The pudendal nerve is a peripheral nerve from the sacral plexus and consists of nerve fibers from the 2nd to 4th sacral nerves [^1].

Illustration

Pudendal nerve
Schematic representation of the pudendal nerve in its anatomical course. Image adapted from Wikimedia Commons.

Anatomy

The pudendal nerve exits the pelvis through the infrapiriform foramen and runs dorsally around the ischiadic spine. It then enters the ischiorectal fossa through the lesser sciatic foramen and proceeds along the lateral wall through the pudendal canal, also known as Alcock's canal, to the symphysis and from there with its terminal branch to the dorsal side of the penis or clitoris[^1].

Nerve Branches

In the pudendal canal, numerous branches arise from the pudendal nerve[^1]:

  • The inferior rectal nerves, which as an anatomical variant may also originate directly from the 2nd to 4th sacral nerves. These pass through the wall of the pudendal canal to the perineum, providing motor innervation to the external anal sphincter and sensory innervation to the skin around the anus, as well as the lower two thirds of the anal canal.

  • The perineal nerves branch into deep and superficial branches. The deep branches contribute to the innervation of the external anal sphincter. More superficially, they innervate the bulbospongiosus muscle, ischiocavernosus muscle, and the superficial transverse perineal muscle. The superficial branches provide sensory innervation to the posterior portion of the scrotum via the posterior scrotal nerves in males. In females, the labia majora are supplied via the posterior labial nerves.

  • The dorsal nerve of the penis or dorsal nerve of the clitoris represents the terminal branch of the pudendal nerve in males and females, respectively. Motor branches from this nerve run to the deep transverse perineal muscle, deep sphincter muscle, and urethral sphincter. After passing through the urogenital diaphragm, it gives off a branch to the corpus cavernosum penis in males or corpus cavernosum clitoridis in females.

Clinical Relevance

Compression of the pudendal nerve can lead to pudendal neuralgia, which depending on the cause and severity, can be treated surgically or conservatively[^2]