Final answer:
At the glenoid cavity, the scapula and the proximal end of the humerus articulate to form the glenohumeral joint or shoulder joint, which allows for a wide range of shoulder movements.
Step-by-step explanation:
At the glenoid cavity, the scapula articulates with the proximal end of the humerus to form the glenohumeral joint, commonly known as the shoulder joint. This joint is a multiaxial ball-and-socket joint that allows for a wide range of motions, including flexion/extension, abduction/adduction, circumduction, and medial/lateral rotation of the humerus.
The head of the humerus is a smooth, rounded region on the medial side of the proximal humerus that articulates with the shallow glenoid fossa of the scapula.
The articular capsule surrounding the glenohumeral joint is relatively thin and loose, facilitating these large motions, while structural support is provided by weak intrinsic ligaments, including the coracohumeral ligament and glenohumeral ligaments, which strengthen the superior and anterior walls of the articular capsule.