Nervous System

Peripheral Nervous System: Somatic Nervous System

What is a plexus?

A plexus (from the Latin plectere, meaning “braid”) is an interwoven network of spinal nerves. There are four major plexuses on each side of the body: 1) the cervical plexus innervates the muscles of the neck, the skin of the neck, the back of the head, and the diaphragm muscle; 2) the brachial plexus innervates the shoulder and upper limb; 3) the lumbar plexus innervates the muscles and skin of the abdominal wall; and 4) the sacral plexus innervates the buttocks and lower limbs. The nerves then divide into smaller branches.


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