How Bones Move

HOW BONES MOVE

•    Bones move with the help of joints.

•    Joints cannot bring about movement without the help of muscles.

•    Muscles bring about movement by contracting (shortening) and relaxing (lengthening).

•    One end of a muscle is attached to a movable bone, whereas the other end is attached to a fixed bone.

•    When the muscle contracts, it pulls the movable bone.

•    Since muscles are only capable of pulling, they work in pairs.

•    A pair of muscles 'biceps and triceps' helps us to move our arm.

•    The muscles in our legs work in a similar manner.

•    When arm is straightened, biceps relax (lengthens) while triceps contract (shortens).

•    When arm is bent, biceps contract (shortens) while triceps relax (lengthens).

Cartilage:

•    The ends of the bones are covered with a tough, elastic tissue called cartilage.

•    Cartilage makes the ends of the bones smooth and reduces friction between the bones during movement.

•    Cartilage is also present in various other parts of our body.

•    We could feel cartilage in the upper part of our ear and in the front part of our nose.

•    These parts are not as hard as bones and can be bent.