Sciatic nerve Sciatic nerve The sciatic nerve (also called "ischiadic nerve", "ischiatic nerve") is a large nerve in humans and other animals. It begins in the lower back and runs through the buttock and down the lower limb. It is the longest and widest single nerve in the human body, going from the top of the leg to the foot on the posterior aspect. The sciatic nerve provides the connection to the nervous system for nearly the whole of the skin of the leg, the muscles of the back of the thigh, and those of the leg and foot. It is derived
Nerve supply to the skin the most densely innervated parts of the body. Though there is no specific categorization, both “free” nerve endings and unencapsulated nerve endings of myelinated axons are found within the dermis of those areas. The cornea, one of the other exposed mucous membranes, contains “free” nerve endings served by nonmyelinated axons. The conjunctiva contains a less dense distribution of “free” nerve endings that are served by both myelinated and unmyelinated axons. The distribution of the sensory neurons within the skin accounts for the large and overlapping receptive fields of the skin. The size of the receptive fields in turn explains why