At what point does the subclavian artery become the axillary artery?

The transition from the subclavian artery to the axillary artery occurs at the outer border of the first rib. This anatomical landmark is significant because it marks the point where the vascular structures change due to their passage from the thoracic cavity into the upper limb. The subclavian artery supplies blood to the upper extremities and branches off into several major arteries, but it is distinctly identified as the subclavian until it crosses the plane of the first rib.

At this point, the artery is officially referred to as the axillary artery, which then gives rise to several branches that supply the shoulder, upper arm, and adjacent tissues. Understanding this transition is crucial for vascular technologists when assessing blood flow and identifying potential vascular issues in this region. The other options do not accurately describe the anatomical changeover point, as they refer to landmarks that are either further along the vascular pathway or do not correspond to the actual transition of nomenclature.