ball-and-socket joint : A ball-shaped head that fits into a bony socket. The shoulder and hip are ball-and-socket joints. This type of joint allows for free movement in several directions, including flexion, extension, abduction, adduction, medial and lateral rotation, and circumduction.

bilateral : On both the left and right sides of the body, such as the eyes, the kidneys, and the arms and legs.

bladder: A thin-walled, bag-like organ that can hold up to two cups of urine.

bony process: A projection of bone that sticks out from the arch found in vertebrae.

brainstem : Connects the cerebrum with the spinal cord.

bursae: Fluid-filled sacs that help tendons glide over the bones and other tendons.

bursitis : An inflammation of a bursa, which is usually the result of repetitive motion injuries.