The posterior cutaneous nerve of the thigh (also called the posterior femoral cutaneous nerve) provides innervation to the skin

Skin

-Dermis:The dermis is the layer of skin beneath the epidermis that consists of connective tissue and cushions the body from stress and strain. The dermis is tightly connected to the epidermis by a basement membrane. It also harbors many Mechanoreceptors that provide the sense of touch and heat...

 of the posterior surface of the thigh

Thigh

In humans the thigh is the area between the pelvis and the knee. Anatomically, it is part of the lower limb.The single bone in the thigh is called the femur...

 and leg

Leg

Łęg may refer to the following places in Poland:*A former name for the town of Ełk *Part of the Czyżyny district of Kraków*Łęg, Pleszew County in Greater Poland Voivodeship...

, as well as to the skin of the perineum

Perineum

In human anatomy, the perineum is a region of the body including the perineal body and surrounding structures...

.

Structure

The posterior cutaneous nerve of the thigh is a nerve from the sacral plexus

Sacral plexus

-External links:*...

. 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

Greater sciatic foramen

-Boundaries:It is bounded as follows:* anterolaterally by the greater sciatic notch of the illium* posteromedially by the sacrotuberous ligament* inferiorly by the sacrospinous ligament and the ischial spine* superiorly by the anterior sacroilliac ligament...

 below the piriformis muscle.

It then descends beneath the gluteus maximus with the inferior gluteal artery

Inferior gluteal artery

The inferior gluteal artery , the larger of the two terminal branches of the anterior trunk of the internal iliac artery, is distributed chiefly to the buttock and back of the thigh....

, and runs down the back of the thigh beneath the fascia lata

Fascia lata

-Thickness:It is an investment for the whole of the thigh, but varies in thickness in different parts.Thus, it is thicker in the upper and lateral part of the thigh, where it receives a fibrous expansion from the Glutæus maximus, and where the Tensor fasciæ latæ is inserted between its layers; it...

, and over the long head of the biceps femoris to the back of the knee; here it pierces the deep fascia

Deep fascia

Deep fascia is a layer of fascia which can surround individual muscles, and divide groups of muscles into compartments....

 and accompanies the small saphenous vein

Small saphenous vein

The small saphenous vein , is a relatively large vein of the superficial posterior leg.-Path:Its origin is where the dorsal vein from the fifth digit merges with the dorsal venous arch of the foot, which attaches to the great saphenous vein...

 to about the middle of the back of the leg, its terminal twigs communicating with the sural nerve

Sural nerve

The sural nerve , formed by the junction of the medial sural cutaneous with the peroneal anastomotic branch of the lateral sural cutaneous nerve, passes downward near the lateral margin of the tendo calcaneus, lying close to the small saphenous vein, to the interval between the lateral malleolus...

.

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
  Perineal branches of posterior femoral cutaneous nerve
  The perineal branches of the posterior femoral cutaneous nerve are distributed to the skin at the upper and medial side of the thigh.One long perineal branch, inferior pudendal , curves forward below and in front of the ischial tuberosity, pierces the fascia lata, and runs forward beneath the...
  
   are distributed to the skin at the upper and medial side of the thigh
  Thigh
  In humans the thigh is the area between the pelvis and the knee. Anatomically, it is part of the lower limb.The single bone in the thigh is called the femur...
  
  .
• 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
  Popliteal fossa
  The popliteal fossa is a shallow depression located at the back of the knee joint. The bones of the popliteal fossa are the femur and the tibia.-Boundaries:The boundaries of the fossa are:-Roof:...
  
  , and the upper part of the back of the leg.