Brachial plexus

Brachial plexus - A collection of large nerve trunks that are formed from nerve roots of the lower part of the cervical spine (in the neck) and the upper part of the thoracic spine (in the chest).

These nerve trunks divide into the musculocutaneous, axillary, median, ulnar, and radial nerves, which control muscles in and receive sensation from the arm and hand. Injuries to this plexus can cause loss of movement and sensation in the arm.

In severe injuries, there may be damage to both the upper and the lower nerve roots of the brachial plexus, producing complete paralysis of the arm. Paralysis may be temporary if the stretching was not severe enough to tear nerve fibres.

Nerve roots that have been torn can be repaired by nerve grafting, a microsurgery procedure. If a nerve root has become separated from the spinal cord, surgical repair will not be successful. Apart from injuries, the brachial plexus may be compressed by the presence of a cervical rib (extra rib).