Obturator

The obturator nerve in human anatomy arises from the ventral divisions of the second, third, and fourth lumbar nerves in the lumbar plexus; the branch from the third is the largest, while that from the second is often very small. The obturator nerve is responsible for the sensory innervation of the skin of the medial aspect of the thigh. The nerve is also responsible for the motor innervation of the adductor muscles of the lower limb (external obturator, adductor longus, adductor brevis, adductor magnus, gracilis) and the pectineus (inconstant). It is, notably, not responsible for the innervation of the obturator internus, despite the similarity in, name.

Since the lumbar plexus and sacral plexus are interconnected, they are sometimes referred to as the lumbosacral plexus. the intercostal nerves that give rami to the chest and to the upper parts of the abdominal wall efferent motor innervation and to the pleura and peritoneum afferent sensory innervation are the only ones that do not originate from a plexus. the ventral rami of l1-l5 spinal nerves with a contribution of t12 form lumbar plexus. this plexus lies within the psoas major muscle. nervi of the plexus serve the skin and the muscles of the lower abdominal wall, the thigh and external genitals. the largest nerve of the plexus is the femoral nerve. it supplies anterior muscles of the thigh and a part of skin distal to the inguinal ligament.