Bones provide the primary framework that supports the entire body. Because the bones support the body, they allow weight bearing and movement. Each bone is made up of several layers of tissue in which new cells are constantly being made and old ones re-absorbed. Some bones protect the tissue beneath them, such as the skull protecting the brain.

There are three types of muscles: cardiac (striated, involuntary), smooth (non striated, involuntary) and skeletal (striated, voluntary). The heart is made up of cardiac muscles which contract spontaneously to pump blood. Smooth muscle is found in hollow organs, such as the stomach, intestines, and trachea. Nerves and hormones regulate smooth muscle activity. Skeletal muscles are attached to bones and require nerves to stimulate contraction. When the muscles contract, it forces the bones to move.

A joint, or articulation, is the location where two bones come together. Joints keep the bones in position, while allowing them to move next to each other. The ends of the bones are covered with cartilage, which provides a cushion between the two bones. Further cushioning is provided by synovial fluid that fills a capsule surrounding the ends of the bones. Joints are described based on the type of movement allowed. For example, the hip and shoulder make up two ball and socket joints. The elbow and knee are hinge joints. In the wrist, the bones move along the surface of other bones making a gliding joint.

Fascia is the connective tissue sitting under the skin and surrounding muscles. The fascia separates muscles, keeping them apart, while allowing them to glide over each other.