Brachial plexus

The brachial plexus is a nerve plexus that originates from the ventral rami of spinal nerves C5, C6, C7, C8, and T1, and supplies both motor and sensory innervation to the entire upper extremity.  The roots of the plexus (C5-T1) combine and split and combine again as they form trunks, divisions, cords, and finally the 5 terminal nerves that supply the extremity.