Neurological testing of a patient reveals no cutaneous sensation on the tip of the index finger. Such a finding would indicate injury to some poion of which nerve?
The median nerve provides cutaneous innervation to the skin of the radial half of the palm and palmar side of the lateral 3 1/2 digits. It also supplies the tips of these fingers and the nail beds on the dorsal side of the hand. So, cutaneous sensation at the tip of the index finger is supplied by the median nerve. The radial nerve supplies cutaneous innervation to the skin of the radial half of the dorsum of the hand and the dorsal side of the lateral 3 1/2 digits, stopping at the nail bed. This nerve is not innervating the tip of the finger. The ulnar nerve supplies the skin of the medial side of the wrist and hand (on both the dorsal and palmar sides of the hand), as well as the skin of the medial 1 1/2 digits. The axillary nerve supplies some cutaneous sensation in the upper arm, and the musculocutaneous nerve supplies cutaneous sensation to the anterolateral forearm through the lateral antebrachial cutaneous nerve.
Axillary
Median
Musculocutaneous
Radial