1. The largest nerve in the body, which begins from nerve roots in the lumbar spinal cord in the low back (sacrum) and extends through the buttock area, sending nerve endings down through the legs and knees.
2. The largest nerve in the body, arising from the sacral plexus on either side, passing from the pelvis through the greater sciatic foramen, and down the back of the thigh, where it divides into the tibial and peroneal nerves.

The posterior femoral cutaneous nerve, a cutaneous nerve supplying the skin of the buttocks, perineum (region of the abdomen surrounding the urogenital and anal openings), popliteal region (area behind the knee joint), and the back of the thigh and the leg.