Bursae synoviales

A synovial bursa (plural bursae or bursas) is a small fluid-filled sac lined by synovial membrane with an inner capillary layer of viscous synovial fluid (similar in consistency to that of a raw egg white).

It provides a cushion between bones and tendons and/or muscles around a joint.

This helps to reduce friction between the bones and allows free movement.

Bursae are found around most major joints of the body.