How do the skeletal system and muscular systems interact? What is the function of joints in this relationship?

Simply put, the muscles of the muscular system move the bones of the skeletal system.

Bones come together at joints. Skeletal muscle is connected to the bones. Motor neurons connect to individual muscle fibers. Electrical signals, or nerve impulses that are known as action potentials, from the motor neurons cause the muscles to contract. When a muscle contracts, connective tissue at the joint draws the connected bone in the position that is dictated by the structure of the joint to which the moving bones are attached.

Examples of different types of joints and the movements that they allow for are identified below.

•  Ball-and-socket joints consisted of a ball-shaped head that is held within a cavity. Ball-and-socket joints allow for a range of motion like no other type of joint. The hip and should consist of ball-and-socket joints.


•  Gliding joints are flat at the point of intersection. The allow for a back-and-forth motion or a twisting motion. The wrist and ankle are composed of gliding joints.


•  In a hinge joint, the convex end of one bone fits into the concave end of another. Bones are able to flex in only one plane, such as the elbow.


•  A pivot joint is made by the cylindrical end of one bone fitting into a ring-like formation of another bone. Movement occurs around a central axis, such as the movement of the neck.