Median nerve 
Median Nerve 
The median nerve enters the palm by passing behind 
the flexor retinaculum and through the carpal tunnel. It 
immediately divides into lateral and medial branches. 
The muscular branch takes a recurrent course around 
the lower border of the flexor retinaculum and lies about 
one fingerbreadth distal to the tubercle of the scaphoid; it 
supplies the muscles of the thenar eminence (the abductor 
pollicis brevis, the flexor pollicis brevis, and the opponens 
pollicis) and the 1st lumbrical muscle. 
The cutaneous branches supply the palmar aspect of 
the lateral three and a half fingers and the distal half of the 
dorsal aspect of each finger. One of these branches also supplies 
the second lumbrical muscle. 
Note also that the palmar cutaneous branch of the 
median nerve given off in the front of the forearm (Fig. 9.55) 
crosses anterior to the flexor retinaculum and supplies