A nerve plexus is a plexus (branching network) of intersecting nerves. A nerve plexus is composed of afferent and efferent fibers that arise from the merging of the anterior rami of spinal nerves and blood vessels. There are five spinal nerve plexuses, except in the thoracic region, as well as other forms of autonomic plexuses, many of which are a part of the enteric nervous system. The nerves that arise from the plexuses have both sensory and motor functions. These functions include muscle contraction, the maintenance of body coordination and control, and the reaction to sensations such as heat, cold, pain, and pressure. There are several plexuses in the body, including: Spinal plexuses Cervical plexus - serves the head, neck and shoulders Brachial plexus - serves the chest, shoulders, arms and hands Lumbosacral plexus Lumbar plexus - serves the back, abdomen, groin, thighs, knees, and calves Subsartorial plexus - below the sartorius muscle of thigh Sacral plexus - serves the pelvis, buttocks, genitals, thighs, calves, and feet Pudendal plexus Coccygeal plexus - serves a small region over the coccyx Autonomic plexuses Celiac plexus (solar plexus) - serves internal organs Auerbach's plexus (myenteric plexus) - serves the gastrointestinal tract Meissner's plexus (submucosal plexus) - serves the gastrointestinal tract Pharyngeal plexus of vagus nerve - serves the palate and pharynx Cardiac plexus - serves the heart Spinal plexuses The following table shows the nerves that arise from each spinal plexus as well as the spinal level each plexus arises from. Cervical plexus The Cervical plexus is formed by the ventral rami of the upper four cervical nerves and the upper part of fifth cervical ventral ramus. The network of rami is located deep to the sternocleidomastoid within the neck. The cervical plexus innervates muscles of the neck and areas of skin on the head, neck and chest. The deep branches innervate muscles, while the superficial branches supply areas of skin. A long branch (primarily of fibers of C4 and with contributions of fibers from C3 and C5; nervus phrenicus) innervates muscles of the diaphragm. The cervical plexus also communicates with the cranial nerves vagus nerve and hypoglossal nerve. Brachial plexus The Brachial plexus is formed by the ventral rami of C5-C8-T1 spinal nerves, and lower and upper halves of C4 and T2 spinal nerves. The plexus extends toward the armpit. The ventral rami of C5 and C6 form upper trunk, the ventral