Synovial sheath

The Synovial Sheath is a specialized structure found in the human body, specifically within the joints. It is a layer of synovial membrane that surrounds tendons, allowing them to move freely. The synovial sheath is filled with synovial fluid, which provides lubrication and nutrition to the tendon.

Etymology

The term "synovial" is derived from the Greek word "synovia," which means "like an egg," referring to the viscous fluid found within the sheath. The word "sheath" comes from the Old English "sceath," meaning a protective covering.

Structure

The synovial sheath is a tubular structure that envelops part of a tendon. It is composed of two layers: the outer fibrous layer, or parietal layer, and the inner synovial layer, or visceral layer. The space between these two layers is filled with synovial fluid.

Function

The primary function of the synovial sheath is to reduce friction between the tendon and surrounding structures, allowing for smooth movement. The synovial fluid within the sheath provides lubrication and nourishment to the tendon, aiding in its function and longevity.

Related Terms

• Tendon: A flexible but inelastic cord of strong fibrous collagen tissue attaching a muscle to a bone.
• Synovial Membrane: The soft tissue that lines the non-cartilaginous surfaces within the joints.
• Synovial Fluid: A viscous, non-Newtonian fluid found in the cavities of synovial joints.

See Also

• Synovial Joint
• Tendon Sheath
• Bursa