Sacral plexus (English)

The spinal nerves L4—S5 are shown on the right hand side, each giving an anterior and a posterior ramus. The plexus is formed by the anterior rami of the L4—S4 spinal nerves, while the S5 root joins the coccygeal (Co) root to form the coccygeal plexus.The anterior rami of spinal nerves further split into anterior and posterior divisions and numerous branches arise from each division. They then join together to form the nerves of the sacral plexus, which can be divided into anterior and posterior branches. The anterior branches are the nerve to quadratus femoris, nerve to obturator internus, pudendal nerve, nerves to levator ani and coccygeus. The posterior branches are the nerve to piriformis, superior gluteal nerve, inferior gluteal nerve, posterior femoral cutaneous nerve, perforating cutaneous nerve and pelvic splanchnic nerves. Continuations of spinal nerves L4—S3 converge together to form a single terminal branch, known as the sciatic nerve. It splits into the tibial and common fibular nerves to supply structures of the thigh, leg and foot.