Arm Anatomy PDF

ARM Dr. Redir T Hassan Co- Leader of MSK Module Leader of Phase I  Arm Extends from shoulder to elbow. Divided into two compartments; anterior and posterior by medial and lateral intermuscular septa Anterior compartment contains muscles flex elbow...

ARM Dr. Redir T Hassan Co- Leader of MSK Module Leader of Phase I  Arm Extends from shoulder to elbow. Divided into two compartments; anterior and posterior by medial and lateral intermuscular septa Anterior compartment contains muscles flex elbow joint. Posterior compartment contains muscles extend elbow joint.  Anterior Compartment ❖Muscles: Biceps brachii Brachialis Coracobrachialis ❖ Blood Vessels: Brachial A. Brachial V. ❖ Nerve Supply: Musculocutaneous N.  Muscles ❖Biceps: two heads and two sites of insertion. ❖Coracobrachialis: from coracoid process to med. side of humerus. ❖Brachialis: from ant. surface of humerus to ulnar tuberosity. ❖N. supply: Musculocutaneous ❖Action: elbow flexion, shoulder flexion (Coracobrachialis & Long head of biceps)  Brachial Artery Begins as a continuation of the axillary artery at the lower border of the teres major muscle. It terminates just distal to the elbow joint where it divides into the radial and ulnar arteries. It is palpable along its length. In proximal regions, the brachial artery can be compressed against the medial side of the humerus.  Brachial Artery Branches: 1) Muscular 2) Profunda brachii 3) Humeral nutrient 4) Superior Ulnar collateral 5) Inferior Ulnar collateral 6) Terminal: Radial and Ulnar  Veins Two sets of veins in the arm: Superficial Deep Superficial Veins are two: 1) Basilic V.: at the distal part of arm runs medially then penetrates deep fascia to become med. to brachial A. It becomes the axillary V. at the lower border of the teres major muscle. 2) Cephalic V.: passes superiorly on the anterolateral aspect of the arm and through the anterior wall of the axilla to reach the axillary vein.  Veins Deep Veins are: Paired brachial veins pass along the medial and lateral sides of the brachial artery, receiving tributaries that accompany branches of the artery  Musculocutaneous nerve It leaves the axilla and enters the arm by passing through the coracobrachialis muscle. It passes down the arm in the plane between the biceps brachii and brachialis muscles. After giving rise to motor branches in the arm continues as the lateral cutaneous nerve of forearm. The musculocutaneous nerve provides: motor innervation to all muscles in the anterior compartment of the arm sensory innervation to skin on the lateral surface of the forearm. Posterior Compartment ❖ Muscles: Triceps (Three heads) ❖ Blood Vessels: Profunda brachii artery ❖ Nerve supply: Radial nerve  Deep Artery of Arm (Profunda Brachii A.) It is the largest branch of the brachial artery and has the most superior origin. It accompanies the radial nerve along the radial groove as it passes posteriorly around the shaft of the humerus. It terminates by dividing into middle and radial collateral arteries that participate in the arterial anastomoses around the elbow.  Radial Nerve It originates from the posterior cord of the brachial plexus. It enters the arm by crossing the inferior margin of the teres major muscle and posterior to the brachial artery, medial to the humerus, and anterior to the long head of the triceps. It run through radial groove & it pierce lateral intermuscular septum then enters the forearm anterior to the lateral epicondyle of the humerus, just deep to the brachioradialis muscle.  Radial Nerve Branches: 1) Muscular branches include those to the triceps brachii, brachioradialis, and extensor carpi radialis longus muscles. 2) Cutaneous branches of the radial nerve that originate in the posterior compartment of the arm are the inferior lateral cutaneous nerve of arm and the posterior cutaneous nerve of forearm  Cubital Fossa It is a triangular depression anterior to elbow joint. Boundaries: 1) Superiorly, an imaginary line connecting the medial and lateral epicondyles. 2) Medially, Pronator teres muscle. 3) Laterally, Brachioradialis. The floor is formed by the brachialis and supinator. The roof is formed by skin, S.C. tissue, fascia and reinforced by the bicipital aponeurosis.  Cubital Fossa Contents: 1) Terminal part of the brachial artery. 2) (Deep) accompanying veins of the arteries. 3) Biceps brachii tendon. 4) Median nerve. 5) Radial nerve. Superficially, the median cubital vein, lying anterior to the brachial artery, and the medial and lateral cutaneous nerves of forearm, related to the basilic and cephalic veins. THANK YOU