Axilla and Brachial Plexus

Question 1

Boundaries of the Axilla

• Anterior wall
• Floor
• Roof
• Posterior wall
• Lateral wall
• Medial wall

Answer 1

• Pec major/minor, subclavius and fascia
• Skin and into arm
• Rib 1, clavicle and scapula
• Subscapularis, teres major, latissimus dorsi, long head of triceps brachii
• Humerus
• Serratus anterior and wall of thorax

Question 2

Axilla Lymphatics

• Axillary nodes drain
• Humeral
• Pectoral
• Subscabular
• Central
• Apical

Answer 2

• Upper limb and mammary tissues
• Posterior to axillary vein and drains upper limb
• Inferior margin of pec minor. Drains thorax and mammary tissue.
• Posterior axillary wall. Drains back, shoulder and neck
• Axillary fat. Communicates with other nodes
• Superior margin of pec minor. Drain other nodes and mammary tissue

Question 3

Brachial Plexus

• Root value of plexus
• Why have a plexus?
• Superior trunk
• Middle trunk
• Inferior trunk

Answer 3

• Anterior rami of C5-T1
• Possible to maintain some function in other nerves if one root is damaged
• C5+C6
• C7
• C8+T1

Question 4

Divisions of the Brachial Plexus

• Each trunk divides into…
• Anterior, posterior and peripheral divisions

Answer 4

• An anterior and a posterior trunk
• Anterior branches go into flexor components for the arm. Posterior branches go into extensor for arm and forearm and sensory in the back of the hand

Question 5

Terminal Branches from the Brachial Plexus

• Lateral Cord
• Posterior Cord
• Medial Cord

Answer 5

• Musculocutaneous nerve and the lateral root of the median nerve
• Axillary and radial nerves
• Ulnar nerve and medial root of median nerve