Axilla

Question 1

Borders of the axilla

Answer 1

The overall 3D shape of the axilla looks slightly like a pyramid. The borders consist of four sides and a base with an opening at the apex.

• Apex – Also known as the axillary inlet, this is formed by lateral border of the first rib, superior border of scapula, and the posterior border of the clavicle.
• Lateral wall – Formed by intertubecular groove of the humerus.
• Medial wall – Consists of the serratus anterior and the thoracic wall (ribs and intercostal muscles).
• Anterior wall – Contains the pectoralis major and the underlying pectoralis minor and the subclavius muscles.
• Posterior wall – Formed by the subscapularis, teres major and latissimus dorsi.

Question 2

Contents of the axilla

Answer 2

Axillary artery

Axillary vein

Brachial plexus

Biceps brachii and corocobrachialis

Axillary Lymph nodes