Armpit Muscles!
Ever wonder what makes some armpits more deep than others? The muscles that make up the border can make the armpit seem deeper. And, like oftentimes with the body - form is a result of function. The armpit is a little hidden nook for a lot of important things. PS an armpit is also called an axilla, Take a look!
Disclaimer: The information provided is for educational purposes only and does not take the place of medical advice.