The subclavian artery is renamed the artery after it passes over the lateral border of the first rib.

The subclavian artery is renamed the axillary artery after it passes over the lateral border of the first rib. This transition marks a significant anatomical landmark in the vascular system of the upper limb. The subclavian artery is responsible for supplying blood to the upper extremities and parts of the neck and head. As it crosses the first rib, it changes its name and continues to provide blood supply to the axilla (armpit area) and the arm through its branches.

The axillary artery is divided into three parts based on its relationship with the pectoralis minor muscle:

1. First part: Located medial to the pectoralis minor, which gives rise to the superior thoracic artery.
2. Second part: Located posterior to the pectoralis minor, which gives rise to the thoracoacromial artery and lateral thoracic artery.
3. Third part: Located lateral to the pectoralis minor, which branches into three major arteries: the subscapular artery, the anterior circumflex humeral artery, and the posterior circumflex humeral artery.

This anatomical knowledge is vital for healthcare professionals for surgical approaches, diagnosing vascular diseases, and managing anatomic variations in patients.