The posterior cutaneous nerve of arm (internal cutaneous branch of musculospiral, posterior brachial cutaneous nerve) is a branch of the radial nerve

Radial nerve

The radial nerve is a nerve in the human body that supplies the upper limb. It supplies 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...

 that provides sensory innervation for much of the skin on the back of the arm. It arises in the axilla.

It is of small size, and passes through the axilla to the medial side of the area supplying the skin on its dorsal surface nearly as far as the olecranon

Olecranon

The olecranon is a large, thick, curved bony eminence of the forearm that projects behind the elbow.It is situated at the upper end of the ulna, one of the two bones in the forearm...

.

In its course it crosses behind and communicates with the intercostobrachial.

See also

• Superior lateral cutaneous nerve of arm
  Superior lateral cutaneous nerve of arm
  The superior lateral cutaneous nerve of arm is the continuation of the posterior cord of the axillary nerve, after it pierces the deep fascia.-Course and targets:...
  
  
• Inferior lateral cutaneous nerve of arm
  Inferior lateral cutaneous nerve of arm
  The inferior lateral cutaneous nerve of arm is a nerve found in humans and other animals. It is also called the inferior lateral brachial cutaneous nerve...
  
  
• Medial cutaneous nerve of arm
  Medial cutaneous nerve of arm
  The medial brachial cutaneous nerve is distributed to the skin on the medial brachial side of the arm.-Anatomy:...
  
  
• Posterior cutaneous nerve of forearm
  Posterior cutaneous nerve of forearm
  The posterior cutaneous nerve of forearm is a nerve found in humans and other animals. It is also known as the dorsal antebrachial cutaneous nerve, the external cutaneous branch of the musculospiral nerve, and the posterior antebrachial cutaneous nerve...