The Skeletal System-Articulations--hinge joint, pivot joint, saddle joint

Pivot joint

A pivot joint allows rotational movement around a single axis, such as is found between the atlas (C1) and axis (C2) of the vertebral column.

What is at the end of the synovial joint?

In a synovial joint, the ends of the bones are smooth and are covered by articular cartilage with an extremely low coefficient of friction.

saddle joint:

This highly mobile joint allows sliding movement in two directions; this type of joint is found where the metacarpals of the thumb meets the trapezium of the wrist.

Hinge joint:

This joint type can move in one plane only, providing flexion and extension:

What are examples of the hinge joint?

the elbow and knee joint are examples of the Hinge joint.

coefficient of friction

the ratio between the force necessary to move one surface horizontally over another and the pressure between the two surfaces