Which of the following is classified as a ball-and-socket joint?

• A. Intervertebral joint
• B. Shoulder joint
• C. Knee joint
• D. Elbow joint

Answer: (B)

Verified step by step guidance

1. Step 1: Understand the classification of synovial joints. Synovial joints are categorized based on their structure and the type of movement they allow. Ball-and-socket joints are one type of synovial joint that permits movement in multiple axes and planes, including rotation.
2. Step 2: Recall the defining features of a ball-and-socket joint. These joints consist of a spherical head (the 'ball') of one bone fitting into a cup-like cavity (the 'socket') of another bone. This structure allows for a wide range of motion, including flexion, extension, abduction, adduction, and rotation.
3. Step 3: Analyze the options provided in the question. The intervertebral joint, knee joint, and elbow joint are not ball-and-socket joints. The intervertebral joint is classified as a cartilaginous joint, while the knee and elbow joints are hinge joints, allowing movement primarily in one plane.
4. Step 4: Identify the shoulder joint as the correct answer. The shoulder joint (glenohumeral joint) is a ball-and-socket joint, where the spherical head of the humerus fits into the glenoid cavity of the scapula, enabling a wide range of motion.
5. Step 5: Conclude that the shoulder joint is the correct classification for a ball-and-socket joint based on its anatomical structure and functional characteristics.