AEMCA Practice Exam

What type of joint classification is characterized by being freely movable?

1. Synarthroses

2. Amphiarthroses

3. Diarthroses

4. Fibrous

The correct answer is: Diarthroses

The classification of joints as freely movable is specifically attributed to diarthroses. This type encompasses joints that have a high degree of mobility, allowing for a wide range of motion in various directions. Diarthroses are typically characterized by a synovial cavity, the presence of articular cartilage covering the surfaces of the bones, and a joint capsule that encloses the joint structure. Examples of diarthroses include the knee, elbow, and shoulder joints, all of which facilitate extensive movement necessary for various physical activities. In contrast, synarthroses are immovable joints, such as those found in the skull, where the bones are tightly fused together. Amphiarthroses are joints that allow slight movement, such as the intervertebral discs in the spine. Fibrous joints are a category that can include both synarthroses and amphiarthroses, depending on the specific type of connection and the extent of mobility allowed. Thus, diarthroses stand out due to their distinct characteristic of being freely movable, enabling dynamic movement essential for daily activities and athletic performance.