- Pectoralis major.
- Pectoralis minor.
- Clavipectoral fascia.
- Teres major.
- Latissimus dorsi.
- Short head of Biceps.
- Upper part of humerus.
- Upper four ribs with their intercostals muscles.
- Upper part of serratus anterior muscle.
Base: It is formed by the skin and fascia.
Apex: It is directed upwards and medially towards the neck.
It is bounded by:
In front: By posterior surface of clavicle.
Behind: By superior border of scapula.
Medially: By outer border of first rib.
- Axillary artery & its branches.
- Axillary vein & its tributaries.
- Lower part of brachial plexus & its infraclavicular branches.
- Lateral cutaneous branches of 2nd & 3rd intercostals nerve.
- Terminal part of cephalic vein.
- Long thoracic nerve.
- Five groups of axillary lymph nodes and lymph vessels.
- Axillary fat.