Anatomy
Course
Arises anterior to the axillary artery from the medial and lateral cords of the brachial plexus. It passes through the arm in the anterior compartment on the medial side between the biceps brachii and the brachialis muscle. It then crosses over the medial epicondyle of the humerus.
It then enters the forearm from the cubital fossa, passing through the two heads of the pronator teres muscle and passing under the arch of the flexor digitorum superficialis tendon. It then continues distally in the fascia beneath the flexor digitorum superficialis muscle.
It leaves the forearm and enters the hand through the carpal tunnel between the tendons of the palmaris longus and the flexor carpi radialis muscle, deep to the flexor retinaculum.
Supply
The median nerve innervates all of the muscles in the anterior compartment of the forearm, except for flexor carpi ulnaris and some of the flexor digitorum profundus.
Clinical
Carpal tunnel syndrome is caused as a result of median nerve compression, as the median nerve is the only one to pass through the carpal tunnel. Compression here results in a tingling sensation over the distribution of the median nerve in the hand, with a pain that may be worse at night than during the day.
Interested in taking our award-winning Pocket Anatomy app for a test drive?
