Median nerve of the right hand
Human hand with course and branches of the median nerve (yellow). The median nerve is a motor and sensory nerve that supplies the motor innervation of the hand, specifically the thumb muscles. The sensory innervation of the first three fingers and the thumbward side of the forth finger is well visible. At the wrist the nerve is under the transverse carpal ligament. This ligament can irritate or even pinch the nerve and thus cause a carpal tunnel syndrome, which causes pain, prickling, a sensation of cold and muscle weakness.
