• All muscles of the anterior compartment of the arm and forearm are flexors and are supplied by the lateral and medial cords of the brachial plexus.
• All muscles of the posterior compartment of the arm and forearm are extensors and are supplied by the posterior cord of the brachial plexus.
• The humerus can be used as a division between the anterior and posterior compartments of the arm.
• The radius and ulna, along with the interosseous membrane between them, can be used as the divisions between the anterior and posterior compartments of the forearm.
• Palmaris Longus may be present in some cadavers and absent in others.  Be sure to identify each variation.

• In these sessions, it will become necessary, at some point, to flip the cadaver from the supine to the prone position so that access to the shoulder region can be attained.  This can be accomplished quite easily by following these steps and paying particular attention during the laboratory demonstration.  Begin by pulling the cadaver to the edge of the table and roll the body onto its side.  Remove the sheet and assist the body in gently toppling into the prone position.  This can be accomplished with two people, one at the chest and one at the legs.

Shoulder:
    1.  The cadaver must be moved to the prone position for the dissection of the shoulder.
    2.  Make an incision from the acromion process of the scapula across the shoulder to the center at the base of the neck.  Continue the incision from the base of the neck down the vertebral column to the level of T10 and extend laterally, creating a flap of skin.
    3.  Remove the underlying fat and fascia exposing the superficial muscles of the shoulder and back.  Note the superficial muscles of the back; trapezius, deltoid, teres major, teres minor, and latissimus dorsi.
    4.  Cut the trapezius muscle one inch from the vertebral column and one inch from its insertion along the acromion and spine of the scapula and reflect the muscle superiorly.  This will expose the rhomboids major and minor, and the SITS muscles of the rotator cuff.  Identify each of these muscles.
    5.  Expose the quadrangular space by cutting the posterior deltiod along its origin at the scapula.  Note the presence of the axillary nerve and posterior humeral circumflex artery passing through the space.
    6.  Expose the lateral triangular space by separate the long and lateral heads of the triceps with the deltoid still reflected.  Note the presence of the radial nerve passing through the space as well as the deep artery of the arm.

Upper Limb:
    7.  From the acromion process, extend an incision down the lateral border of the arm and forearm ending at the wrist.  Be sure to keep the incision limited to the skin as there are cutaneous sensory nerves exiting from deep structures; intact nerves will simplify understanding.  Create an incision around the wrist.  Once the skin has been removed from the underlying tissues, a continuous sheet of skin will have been created which can be rewrapped around the arm when the session is complete.
    8.  Remove the underlying fat and fascia from the arm.
    9.  Remove the underlying fat and fascia from the forearm.  Be careful not to destory the superficial branch of the radial nerve at the lateral aspect of the forearm and wrist.  Once understood, the veins alone may be cut and reflected.
   10.  Place the cadaver in the prone position to view the posterior arm and forearm.
   11.  All the muscles, nerves, arteries and veins of the arm and forearm (both compartments) must be understood as well as cutaneous sensroy innervation to the region.

Hand:
   12.  Extend a superficial incision along the lateral edge of the first metacarpal following the superficial radial nerve as a guide.  Create a small flap of skin by which to gain access to the area named the "Anatomical Snuffbox".  Clean the space of any fat or fascia and note that the radial artery passes through the space.  Be sure to know the borders of this small region.
   13.  Extend an incision from the lateral edge of the first metacarpal across the thenar eminence of the thumb to the base of the second metacarpal.  Continue the incision across the base of all the meatcarpals creating a "flap" of skin attached to the hypothenar eminence.  Remove all of the superficial fat and fascia.  If present, the palmaris longus tendon must be cut and the palmar aponeurosis removed.  Continue the dissection into one digit and open the sheath at the proximal interphalangeal joint.
    14.  Note the madian and ulnar nerve distribution as well as the radial and ulnar artery distribution.  Identifyt the muscles and nerves that are listed on the structures list.