Structure and Functions of the Joints

Joints Have Many Functions:

• Our joints enable us to move. We make many thousands of movements every day, most of them unconsciously. The joints are naturally lubricated to improve and ease these movements. The lubricant consists of a fluid film secreted by the synovial membranes lining the interior of the joints.
• Joints have a shock absorber to cushion sudden, hard movements: the joint cartilage. This even and resilient coating protects the joints during movements and allows movements to progress smoothly.
• Joints provide stability. Joints have important structures that guide certain movements and prohibit others. For example, the joint in the fingertip can move only like a hinge. It does not permit side-to-side movements. The joint is protected against “wrong” movements. This protection is provided by portions of the joint capsule (called the “fibrous capsule”) and the ligaments that “bind” the joint together.