Posterior - lateral view

Lateral view, left side

Lateral view, right side

Posterior view, anatomical position

The glenoid cavity is functionally important because it forms a joint with the head of the humerus.  This is a ball and socket joint that allows for triaxial motion:  flexion/extension, abduction/adduction, and rotation.  It gets its name from the famous senator and astronaut John Glenoid.