Upper limb: arm and brachial plexus

Fascial Compartments of the Upper Arm
The upper arm is enclosed in a sheath of deep fascia
(Fig. 9.41). Two fascial septa, one on the medial side and
one on the lateral side, extend from this sheath and are
attached to the medial and lateral supracondylar ridges of
the humerus, respectively. By this means, the upper arm is
divided into an anterior and a posterior fascial compartment,
each having its muscles, nerves, and arteries.
Contents of the Anterior Fascial Compartment
of the Upper Arm
?? Muscles: Biceps brachii, coracobrachialis, and brachialis
?? Blood supply: Brachial artery (Fig. 9.42)
?? Nerve supply to the muscles: Musculocutaneous nerve
?? Structures passing through the compartment: Musculocutaneous,
median, and ulnar nerves; brachial artery
and basilic vein. The radial nerve is present in the lower
part of the compartment.
Muscles of the Anterior Fascial Compartment
The muscles of the anterior fascial compartment are shown
in Figures 9.43 and 9.44 and are described in Table 9.5.
Note that the biceps brachii is a powerful supinator, and
this action is made use of in twisting the corkscrew into
the cork or driving the screw into wood with a screwdriver.
The biceps also is a powerful flexor of the elbow joint and a
weak flexor of the shoulder joint.