Median nerve: course from the brachial plexus to the carpal tunnel, muscles supplied
Where does the median nerve run?
Bending the wrist, gripping with the fingers, bringing the thumb across to meet them: many fine hand movements depend on the median nerve, named for its course down the middle of the arm.
It leaves the brachial plexus, runs down the inner arm from the armpit, crosses the front of the elbow, descends deep in the middle of the forearm, and enters the palm through the carpal tunnel. teamLabBody lets you select the main nerve, its palmar branch and its thenar (recurrent) branch separately.
Origin: two roots
A lateral root from the lateral cord and a medial root from the medial cord unite in a V in front of the axillary artery. Its fibres come from C6 to T1, sometimes also C5; textbooks give either C5–T1 or C6–T1.
Arm and elbow: no branches
In the arm it runs with the brachial artery, lateral to it above, crossing in front of it in mid-arm, and medial to it near the elbow; it gives no muscular branches in the arm. In the cubital fossa it lies just medial to the artery under the bicipital aponeurosis, with the median cubital vein in the skin above, and enters the forearm between the two heads of pronator teres.
Forearm and hand: flexors and thenar muscles
In the forearm it runs between the flexor digitorum superficialis and profundus and supplies most anterior forearm muscles; its anterior interosseous branch supplies the deepest layer.
・Directly: pronator teres, flexor carpi radialis, palmaris longus, flexor digitorum superficialis
・Anterior interosseous nerve: flexor pollicis longus, lateral half of flexor digitorum profundus, pronator quadratus
At the wrist it passes through the carpal tunnel, formed by the carpal bones and flexor retinaculum, with nine flexor tendons. In the palm it supplies the thenar muscles and the lateral lumbricals and carries sensation from the palmar skin of the thumb to half the ring finger.
Name and terms
Median means in the middle. Related terms: anterior interosseous nerve, carpal tunnel, thenar eminence. The Latin is nervus medianus.
See it in the app
Overlapped by the artery in the arm and by the finger flexors in the forearm, the median nerve disappears in drawings. In the 3D anatomy app teamLabBody you can keep only the bones and the nerve and follow it continuously from the armpit to the wrist, then select its palmar and thenar branches to see where they go. Cross sections are available with the PREMIUM plan.
FAQ
- Where does the median nerve run?
- From the brachial plexus down the inner arm beside the brachial artery, across the front of the elbow, deep in the middle of the forearm, and through the carpal tunnel into the palm.
- Which muscles does the median nerve supply?
- In the forearm, pronator teres, flexor carpi radialis, palmaris longus and flexor digitorum superficialis, and via the anterior interosseous nerve flexor pollicis longus, the lateral half of flexor digitorum profundus and pronator quadratus; in the hand, the thenar muscles and lateral lumbricals.
- What are the roots of the median nerve?
- A lateral root from the lateral cord and a medial root from the medial cord, uniting in front of the axillary artery; its fibres come from C6–T1, with some textbooks including C5.
Related articles
・Brachial plexus: source of the median nerve
・Brachial artery: runs beside it in the arm
・Flexor digitorum superficialis and profundus: the nerve runs between them
・Carpal bones: form the floor of the carpal tunnel
・Abductor pollicis longus and brevis: the brevis is a thenar muscle supplied by the median nerve
