Final answer:
The glenoid cavity is the socket portion of the ball and socket joint of the scapula, which contributes to the articulation forming the shoulder joint.
Step-by-step explanation:
The socket portion of the ball and socket joint of the scapula is called the glenoid cavity. This shallow socket is part of the glenohumeral joint, also known as the shoulder joint, which is formed by the articulation between the head of the humerus and the glenoid cavity of the scapula. The glenoid cavity is deepened slightly by a fibrocartilage rim known as the glenoid labrum. The large range of motion of the shoulder joint is largely due to the articulation of the humeral head with the small and shallow glenoid cavity, complemented by the articular capsule and supporting ligaments.
The glenoid cavity is part of the scapula bone and forms the articulation with the head of the humerus, which is the ball portion of the joint. This joint, called the glenohumeral joint, allows for a wide range of motion in the shoulder.