Radial nerve

Radial nerve
The suprascapular, axillary, and radial nerves.
Details
From	posterior cord
To	posterior interosseous nerve
Innervates	posterior compartment of the arm, posterior compartment of the forearm
Identifiers
Latin	nervus radialis
MeSH	A08.800.800.720.050.700
Dorlands /Elsevier	n_05/12566581
TA	A14.2.03.049
FMA	37069
Anatomical terms of neuroanatomy []

The radial nerve is a nerve in the human body that supplies the posterior portion of the upper limb. It innervates the medial and lateral heads of the triceps brachii muscle of the arm, as well as all 12 muscles in the posterior osteofascial compartment of the forearm and the associated joints and overlying skin.

It originates from the brachial plexus, carrying fibers from the ventral roots of spinal nerves C5, C6, C7, C8 & T1.

The radial nerve and its branches provide motor innervation to the dorsal arm muscles (the triceps brachii and the anconeus) and the extrinsic extensors of the wrists and hands; it also provides cutaneous sensory innervation to most of the back of the hand, except for the back of the little finger and adjacent half of the ring finger (which are innervated by the ulnar nerve).

The radial nerve divides into a deep branch, which becomes the posterior interosseous nerve, and a superficial branch, which goes on to innervate the dorsum (back) of the hand.

The radial nerve originates as a terminal branch of the posterior cord of the brachial plexus. It goes through the arm, first in the posterior compartment of the arm, and later in the anterior compartment of the arm, and continues in the posterior compartment of the forearm.

From the brachial plexus, it travels posteriorly through what is often called the triangular interval (US), the lower triangular space of the axilla (UK) or the triceps hiatus.

Having passed through this inter muscular gap, the radial nerve continues posteriorly in a medial to lateral fashion on the arm while in conjunction with the deep artery of arm.