What is a bursa sac?

A bursa sac is an extremely important compartment found through our body. It can be regarded like a flat balloon with a small portion of oil in the middle. Imagine now that these balloons lay between regions within the body which move against one another, (like inside joints) and you can see how this would permit minimum friction and wear on the bones and cartilage by permitting a smooth gliding effect to take place.

Of course the bursa isn’t really a balloon, actually the bursa sac is essentially made from a special kind of tissue called synovial tissue which is highly vascularised and permits the controlled movement of water and tiny molecules to and from the inside space of the bursa. The oily substance in the middle of the bursa sac which supplies the gliding effect is named Synovial fluid. A major element of healthy and normal synovial fluid is Hyaluronic Acid (HA), a very long chain molecule that gives synovial fluid its viscosity and gliding effect, but which isn’t readily capable of being transported or lost via movement across the synovial tissue.