JAMB - Biology (1999 - No. 32)

The structure labeled II articulates with III to form HINGE JOINT.

Hinge joints are those that allow movement along one plane. They facilitate bending and straightening actions, such as flexing a finger.

In a hinge joint, protective cartilage covers the bones, and a thick gel called synovial fluid lubricates them, allowing them to move without rubbing against one another,

The following body parts are hinge joints: elbow, knee, finger joints, toe joints, and ankles.