Nerve plexus nerves form the Sacral plexus. It is located on the posterior wall of pelvic cavity (pelvis minor). Nervi of the plexus innervate the perineal region, buttocks and the lower limb. The largest nerve of the human body, the sciatic nerve is the main branch, that give rami to the motor innervation of the muscles of the foot, the leg and the thigh. Common peroneal nerve and its branches innervate some part of the skin of the foot, the peroneal muscles of the leg and the dorsal muscles of the foot. Coccygeal plexus originate from S4, S5, Co1 spinal nerves. It
Nerve net The anatomy and positioning of nerve nets can vary from organism to organism. Hydra, which are cnidarians, have a nerve net throughout their body. On the other hand, sea stars, which are echinoderms, have a nerve net in each arm, connected by a central radial nerve ring at the center. This is better suited to controlling more complex movements than a diffuse nerve net. The emergence of true nervous tissue occurred following divergence in the last common ancestor of Porifera (sponges) and Cnidaria and Ctenophora. The existence of nerve nets is best understood by studying the outgroup of Porifera and