Posterior cutaneous nerve of thigh

The posterior cutaneous nerve of the thigh (also called the posterior femoral cutaneous nerve) provides innervation to the skin of the posterior surface of the thigh and leg, as well as to the skin of the perineum.

Structure
The posterior cutaneous nerve of the thigh is a nerve from the sacral plexus. It arises partly from the dorsal divisions of the first and second, and from the ventral divisions of the second and third sacral nerves, and issues from the pelvis through the greater sciatic foramen below the piriformis muscle.

It then descends beneath the gluteus maximus with the inferior gluteal artery, and runs down the back of the thigh beneath the fascia lata, and over the long head of the biceps femoris to the back of the knee; here it pierces the deep fascia and accompanies the small saphenous vein to about the middle of the back of the leg, its terminal twigs communicating with the sural nerve.

Branches
Its branches are all cutaneous, and are distributed to the gluteal region, the perineum, and the back of the thigh and leg.


 * The inferior clunial nerves (or gluteal branches), three or four in number, turn upward around the lower border of the gluteus maximus, and supply the skin covering the lower and lateral part of that muscle.
 * The perineal branches are distributed to the skin at the upper and medial side of the thigh.
 * The main part to the back of the thigh and leg consists of numerous filaments derived from both sides of the nerve, and distributed to the skin covering the back and medial side of the thigh, the popliteal fossa, and the upper part of the back of the leg.