<P> The radial nerve, which is from the fifth cervical spinal nerve to the first thoracic spinal nerve, originates as the continuation of the posterior cord of the brachial plexus . This nerve enters the lower triangular space (an imaginary space bounded by, amongst others, the shaft of the humerus and the triceps brachii) of the arm and lies deep to the triceps brachii . Here it travels with the deep artery of the arm, which sits in the radial groove of the humerus . This fact is very important clinically as a fracture of the shaft of the bone here can cause lesions or even transections in the nerve . </P> <P> Other nerves passing through give no supply to the arm . These include: </P> <Ul> <Li> The median nerve, nerve origin C5 - T1, which is a branch of the lateral and medial cords of the brachial plexus . This nerve continues in the arm, travelling in a plane between the biceps and triceps muscles . At the cubital fossa, this nerve is deep to the pronator teres muscle and is the most medial structure in the fossa . The nerve passes into the forearm . </Li> <Li> The ulnar nerve, origin C8 - T1, is a continuation of the medial cord of the brachial plexus . This nerve passes in the same plane as the median nerve, between the biceps and triceps muscles . At the elbow, this nerve travels posterior to the medial epicondyle of the humerus . This means that condylar fractures can cause lesion to this nerve . </Li> </Ul> <Li> The median nerve, nerve origin C5 - T1, which is a branch of the lateral and medial cords of the brachial plexus . This nerve continues in the arm, travelling in a plane between the biceps and triceps muscles . At the cubital fossa, this nerve is deep to the pronator teres muscle and is the most medial structure in the fossa . The nerve passes into the forearm . </Li>

Where is the biceps located in the body