What is armpit anatomically?

The armpit, also known as the axilla, is a shallow hollow area located beneath the shoulder joint. It is an anatomical structure formed by the convergence of muscles, bones, nerves, blood vessels, and lymphatic vessels. It is bordered by the ribcage and the upper arm bone and covered by a layer of skin and subcutaneous adipose tissue.

The armpit is rich in lymph nodes and lymphatic vessels, which function to filter out harmful substances, bacteria, and viruses from the lymphatic fluid. This makes the armpit a crucial site for immune system function. The lymphatic vessels in the armpit ultimately drain into a larger structure called the thoracic duct, which is responsible for returning lymphatic fluid back into the circulatory system.

The armpit is also home to numerous sweat glands, which are responsible for producing sweat to help regulate body temperature. These sweat glands can become clogged, leading to conditions such as cysts or abscesses.

Finally, the armpit contains a variety of important structures, including nerves that supply sensation to the arm, muscles that move the arm and shoulder, and blood vessels that supply oxygenated blood to the upper limb.