Final answer:
The AC joint refers to the acromioclavicular joint, which is found in the shoulder. It is where the acromion of the scapula meets the clavicle. The rotator cuff surrounds this area and is essential for shoulder stability and motion.
Step-by-step explanation:
The AC joint, or acromioclavicular joint, is a joint located in the shoulder. It is where the acromion, a part of the scapula, meets the clavicle. The rotator cuff is a group of muscles and tendons that surround the shoulder joint, providing stability and allowing a wide range of movements. The comprised tendons from the rotator cuff muscles attach to the humeral head and are integral in shoulder movement and health.
The options provided refer to different joints in the body, which include:
- a. glenohumeral joint: This is the ball-and-socket joint of the shoulder that provides the widest range of motion.
- b. costoclavicular joint: This is not commonly recognized as a major joint and is related to the attachment of the rib (costa) to the clavicle.
- c. acromioclavicular joint: This is the correct answer, representing the AC joint in the shoulder where the acromion and the clavicle meet.
- d. sternoclavicular joint: This joint is at the medial end of the clavicle where it meets the sternum (chest).
Therefore, the correct answer to the student's question is (b) Joint in the shoulder, which corresponds to the acromioclavicular joint.