Vegetation acts as an interface between the atmosphere and the soil. It increases the permeability of the soil to rainwater, thus decreasing runoff. It shelters the soil from winds, which results in decreased wind erosion, as well as advantageous changes in microclimate.
The shoulder is a ball-and-socket type of joint and is anatomically referred to as the gleno-humeral joint, describing the two bony structures involved. The socket is the glenoid cavity, a cup-shaped piece of bone that juts out from a corner of the shoulder blade (scapula).
Plural: labra. The glenoid labrum is a ring of fibrocartilage that runs around the cavity of the scapula (wingbone) in which the head of the humerus (the bone in the upper arm) fits. The labrum deepens this cavity (the glenoid cavity) and effectively increases the surface of the shoulder joint.