Page 210 - Clinical Anatomy

ECA3 7/18/06 6:45 PM Page 195

Course and distribution of nerves 195

Fig. 142◊Dissection of the upper arm to show the course of the major nerves.

and a deep terminal branch which supplies the hypothenar muscles and
the intrinsic muscles of the hand.
Its branches are:
•◊◊muscular— to flexor carpi ulnaris, medial half of flexor digitorum pro-
fundus, the hypothenar muscles, the interossei, 3rd and 4th lumbricals and
the adductor pollicis (i.e. it supplies all the intrinsic muscles of the hand
apart from those of the thenar eminence and the 1st and 2nd lumbricals,
which are innervated by the median nerve);
•◊◊cutaneous— to the ulnar side of both aspects of the hand and both sur-
1
faces of the ulnar 1– fingers.
2
The median nerve
The median nerve (C6, 7, 8, T1; Fig. 142) arises by the junction of a branch
from the medial and another from the lateral cord of the plexus, which
unite anterior to the third part of the axillary artery. Continuing along the
lateral aspect of the brachial artery, the nerve then crosses superficially
(occasionally deep) to the artery at the mid-humerus to lie on its medial
side. The nerve enters the forearm between the heads of pronator teres, the
deeper of which separates it from the ulnar artery (Fig. 137). Here the nerve