The term "axillae" refers to the plural form of "axilla," which is the anatomical term for the armpit area of the human body. This region is located beneath the shoulder joint and serves as a passageway for nerves, blood vessels, and lymphatics that connect the upper limb to the trunk. The axillae contain important structures, including the brachial plexus, which is a network of nerves that innervate the arm, and the axillary artery, which supplies blood to the upper limb. Additionally, the axillae are home to lymph nodes that play a crucial role in the immune system.