Sciatic nerve

From ArticleWorld

The sciatic nerve is the main nerve supply to the lower leg. It is the longest named nerve in the body. It originates from a cluster of nerves that exit the spinal cord and form the sacral plexus.

Anatomy

The sciatic nerve forms a single nerve from a coalescence of many small nerves in the sacral plexus near the spine. It passes through the greater sciatic foramen (opening) in the pelvis and passes near the ischial tuberosity of the pelvic bone and down the posterior compartment of the thigh.

Eventually the sciatic nerve divides into smaller segments somewhere near the knee. The main branches of the sciatic nerve are the tibial nerve and the common peroneal nerve. The sural nerve branches from primarily the tibial nerve to supply a portion of the lower leg.

Diseases

The primary illness involving the sciatic nerve is an inflammation of the nerve known as sciatica. The nerve can be inflamed from overuse of the leg, from a stretching injury or from something as simple as sitting. The sciatic nerve is often “pinched” in the area of the posterior pelvis and may involve a relative narrowing of the foramen through which the nerve passes or an inflammation at the sciatic notch, where bone and nerve come in close connection.