What is the name of the joint connecting the upper extremity to the thorax?

• A. Glenohumeral joint
• B. Sternoclavicular joint
• C. Scapulothoracic joint
• D. Costoclavicular joint

Answer: (B)

The joint that connects the upper extremity to the thorax is known as the sternoclavicular joint. This joint is located at the junction where the clavicle (collarbone) meets the sternum (breastbone). It plays a crucial role in the movement of the shoulder and arm by allowing the clavicle to pivot, which is essential for a full range of motion of the upper limb.

This joint is unique because it is the only bony connection between the upper limb and the axial skeleton. Its structure is a synovial joint, which enables a variety of movements, including elevation, depression, protraction, retraction, and limited rotation of the shoulder girdle. As such, the sternoclavicular joint is vital for providing stability and flexibility to the upper extremity during various activities.

The other options pertain to different joints that do not serve the same function of directly connecting the upper extremity to the thorax. For example, the glenohumeral joint is the ball-and-socket joint at the shoulder, the scapulothoracic joint refers to the movement of the scapula over the back of the ribcage, and the costoclavicular joint relates to the connection between the ribs