Axilla Inlet Apex
Axillary apex, is the triangular opening at the top of the armpit (axilla) that connects the neck to the axilla. It is bounded by the lateral border of the first rib, the posterior surface of the clavicle, and the superior border of the scapula, and serves as the passage for major nerves and blood vessels, like the brachial plexus and subclavian vessels, to enter the axilla from the neck.