What type of membranes form the inner lining of joint cavities?

The inner lining of joint cavities is formed by synovial membranes. These membranes are specialized tissues that produce synovial fluid, which is a viscous fluid that lubricates the joints, reducing friction between the articular cartilage of synovial joints during movement. This lubrication is crucial for the proper functioning of joints, allowing for smooth and pain-free motion.

Synovial membranes are distinct from other types of membranes in the body. Mucous membranes line body cavities that open to the outside environment, such as the respiratory and digestive tracts, and are involved in secretion and absorption. Serous membranes, on the other hand, line body cavities that are not open to the exterior, such as the pleura around the lungs or the peritoneum in the abdominal cavity. Cutaneous membranes, commonly referred to as skin, cover the body's external surface.

In summary, synovial membranes are specifically adapted to support joint function by producing the necessary fluid and providing a smooth lining within the cavities of synovial joints.