Answer
brachial plexus radial nerve
Work Step by Step
brachial plexus, situated partly in the neck and partly in the axilla, gives rise to virtually all the nerves that innervate the upper limb.
The ulnar nerve goes into the hand. Where it innervates
most intrinsic hand muscles, and the skin of the medial aspect
of the hand. It causes the wrist and fingers to flex, and adducts and abducts the medial fingers.