Microvilli (singular: microvillus) are microscopic cellular membrane protrusions that increase the surface area of cells and minimize any increase in volume, and are involved in a wide variety of functions, including absorption, secretion, cellular adhesion, and mechanotransduction. 1 Locations.
When youâre experiencing back knee pain, the cause of the problem may be due to a condition known as a Bakerâs cyst. When the back knee pain is associated with a Bakerâs cyst, it isnât a cyst in the usual sense. Itâs a popliteal cyst. What this means is that fluid is present in the joint at the back of the knee.
What is a popliteal cyst. In the hollow at the back of the knee is a bursa or small sack of fluid used to help lubricate the joint. A fairly uncommon condition is when the back of the knee joint gets swollen and causes the bursa to swell as well. Bakers cyst is a rounded swelling at the back of the knee. It is often about the size of a golf ball but can vary over time. A sensation of pressure in the back of the joint will be felt which may go down into the calf muscle.