Ínhüvelyek

Ínhüvelyek, also known as tendon sheaths or synovial sheaths, are protective tubular structures that surround tendons in certain parts of the body, particularly where they pass through narrow or high-friction areas. Their primary function is to reduce friction between the tendon and surrounding tissues, facilitating smooth and efficient movement. This reduction in friction is achieved through the production of synovial fluid, a lubricating substance secreted by the inner lining of the sheath.

These structures are most commonly found in the hands and feet, where tendons are densely packed and undergo significant movement. For example, the tendons of the fingers and thumb are enclosed in synovial sheaths, allowing for the fine motor control necessary for grasping and manipulation. Similarly, in the foot, sheaths protect the tendons that enable walking, running, and other locomotor activities.

Ínhüvelyek consist of two layers: an outer fibrous sheath and an inner synovial membrane. The fibrous sheath provides structural support, while the synovial membrane secretes the lubricating fluid. Inflammation of these sheaths, known as tenosynovitis, can lead to pain, swelling, and restricted movement, often requiring medical attention. Conditions like trigger finger and De Quervain's tenosynovitis are examples of inflammation affecting these tendon sheaths.