bursa

a fluid-filled sac that reduces friction between tissues such as bones, tendons, and muscles

A bursa is a small fluid-filled sac located between bones, tendons, and muscles. It acts as a cushioning structure, reducing friction and providing a smooth surface for the movement of these adjacent tissues. Bursae help to minimize the impact and friction that can occur during joint movement, allowing for smooth and pain-free motion. They are found throughout the body, particularly in areas subject to repetitive motion or pressure.

a city in northwestern Turkey