How many types of synovial joints exist?

How many types of synovial joints exist?

• A. 5
• B. 4
• C. 6
• D. 7

Answer: (C)

Synovial joints are the most movable type of joint, and they’re classified by the shape of the articulating surfaces, which determines the kinds of movements they can perform. There are six distinct types: hinge joints allow flexion and extension, as seen at the elbow; pivot joints enable rotation around a single axis, like the neck between the atlas and axis; condyloid (ellipsoidal) joints permit flexion/extension and abduction/adduction (with circumduction possible), such as the wrist; saddle joints also allow a wide range of movement including opposition, exemplified by the thumb base; ball-and-socket joints provide movement in multiple directions plus rotation, as in the shoulder and hip; plane (gliding) joints allow sliding movements between flat surfaces, such as the joints between carpal bones. Because each type has a unique arrangement and set of movements, there are six types in total.

Synovial joints are the most movable type of joint, and they’re classified by the shape of the articulating surfaces, which determines the kinds of movements they can perform. There are six distinct types: hinge joints allow flexion and extension, as seen at the elbow; pivot joints enable rotation around a single axis, like the neck between the atlas and axis; condyloid (ellipsoidal) joints permit flexion/extension and abduction/adduction (with circumduction possible), such as the wrist; saddle joints also allow a wide range of movement including opposition, exemplified by the thumb base; ball-and-socket joints provide movement in multiple directions plus rotation, as in the shoulder and hip; plane (gliding) joints allow sliding movements between flat surfaces, such as the joints between carpal bones. Because each type has a unique arrangement and set of movements, there are six types in total.