Human leg lumbar plexus. It supplies motor innervation to iliopsoas, pectineus, sartorius, and quadriceps; and sensory branches to the anterior thigh, medial lower leg, and posterior foot. The nerves of the sacral plexus pass behind the hip joint to innervate the posterior part of the thigh, most of the lower leg, and the foot. The superior (L4-S1) and inferior gluteal nerves (L5-S2) innervate the gluteus muscles and the tensor fasciae latae. The posterior femoral cutaneous nerve (S1-S3) contributes sensory branches to the skin on the posterior thigh. The sciatic nerve (L4-S3), the largest and longest nerve in the human body, leaves the
Nerve supply to the skin the kind of sensory inputs which project to a specific region of the primary somatosensory cortex. Groups of nerve terminals located in the different layers of the skin are categorized depending on whether the skin is hairy, nonhairy, or an exposed mucous membrane. The hairy parts of the body such as the forearm or the leg have two groups of nerve endings: those that end along with the hair follicles, and also with the arborizations of unmyelinated axons which are referred to as “free” nerve endings because they are served by both myelinated and unmyelinated axons. Nonhairy skin, such as