Final answer:
The axillary artery is the continuation of the subclavian artery and supplies blood to the region near the head of the humerus. It continues into the brachium and becomes the brachial artery.
Step-by-step explanation:
Course and Relations of the Axillary Artery:
The axillary artery is the continuation of the subclavian artery as it enters the axillary region. It supplies blood to the region near the head of the humerus through the humeral circumflex arteries. The majority of the axillary artery continues into the brachium and becomes the brachial artery.
Relations of the Axillary Artery:
- Anterior Relation: Pectoralis minor muscle and lateral thoracic wall
- Posterior Relations: Subscapularis, teres major, and latissimus dorsi muscles, subscapular artery and vein
- Medial Relation: Upper part of the brachial plexus
- Lateral Relation: Medial side of the humerus
- Superior Relation: Clavipectoral fascia and the 1st rib
- Inferior Relation: Teres major and the humerus