Femoral nerve

The femoral nerve is a nerve in the thigh that supplies skin on the upper thigh and inner leg, and the muscles that extend the knee.

Structure

The femoral nerve is the largest branch of the lumbar plexus, and arises from the dorsal divisions of the ventral rami of the second, third, and fourth lumbar nerves (L2-L4).

It descends through the fibers of the psoas major muscle, emerging from the muscle at the lower part of its lateral border, and passes down between it and the iliacus muscle, behind the iliac fascia; it then runs beneath the inguinal ligament, into the thigh, and splits into an anterior and a posterior division. Under the inguinal ligament, it is separated from the femoral artery by a portion of the psoas major.

Function

The muscles innervated by the femoral nerve extend the knee. The nerve is also responsible for sensation over the front and inner sides of the thigh, shin, and arch of the foot.

Branches

Within the abdomen the femoral nerve gives off small branches to the iliacus muscle, and a branch which is distributed on the upper part of the femoral artery; the latter branch may arise in the thigh.