ledvävnad

Ledvävnad, often translated as synovial tissue or synovium, is a specialized connective tissue that lines the inner surface of diarthrodial joints, which are freely movable joints such as the knee, hip, and shoulder. Its primary function is to produce synovial fluid, a viscous, non-Newtonian fluid that lubricates the joint, reduces friction between the articular cartilages, and provides nourishment to these avascular tissues.

The synovial tissue is typically composed of two layers: the intima and the subintima. The intima is the innermost layer and consists of specialized cells called synoviocytes. There are two main types of synoviocytes: type A (macrophage-like) cells, which are responsible for clearing debris and maintaining the joint's health, and type B (fibroblast-like) cells, which produce the components of synovial fluid, primarily hyaluronic acid and lubricin. The subintima is a supportive layer containing blood vessels, nerves, and various connective tissue elements like collagen and elastic fibers.

The health and proper functioning of ledvävnad are crucial for joint mobility and integrity. Inflammation of the synovial tissue, known as synovitis, can occur due to various conditions, including arthritis (rheumatoid arthritis, osteoarthritis), infection, or injury. Synovitis leads to increased production of synovial fluid, joint swelling, pain, and stiffness, potentially causing damage to other joint structures over time if left untreated.