The skeletal and muscular systems Bones and muscles

The skeletal and muscular systems

Bones and muscles l The bones in the body form the skeletal system. This provides a framework for the body. This framework provides support for muscles; it also protects vital organs. l Together the bones and muscles allow the body to move.

SKELETAL SYSTEM THE SKELETON IS THE NAME GIVEN TO A COLLECTION OF BONES. IT HAS THREE MAJOR ROLES; l PROTECTION (bones protect the vital organs in the body) l SHAPE (without our bones we would be a blob of tissue and blood on the floor) l MOVEMENT (the muscle are attached to bones and they pull on the bones to make us move)

Challenge:

Skeletal system l Task : copy out skeletal sheet. l Name 3 organs that bones protect l Describe in your own words what a joint is

Joints l. A JOINT is where two or more bones meet. l There are 3 types of joints; l 1 - fixed l 2 -slightly moveable l 3 -freely moveable

FREELY MOVEABLE JOINTS These are joints which allows movement in one or more direction. l The hinge joint (knee) and ball and socket (shoulder) joints are both freely moveable. l

Hinge joint l Hinge joints, like in your knee and elbow, enable movement similar to the opening and closing of a hinged door.

Ball and socket l Ball and socket joints, like your hip and shoulder joints, are the most mobile type of joint in the human body. They allow you to swing your arms and legs in many different directions.

Freely moveable

TASK l Using the textbook, describe the function of each of the following: l Tendons l Cartilage l Ligaments

Muscular system l Every movement of your body depends on muscle. These are three different types of muscle: l Involuntary (smooth) surrounding hollow organs e. g. blood vessels, gut. l Voluntary (skeletal) found mainly attached to the skeleton, under conscious control l Cardiac (found only on the walls of the heart)

Skeletal muscles The muscles of the body allow movement at a joint. l Each muscle is attached to the bone by a tendon. The tendon which is attached to the bone that does not move is know as the origin. The tendon which is attached to the bone that moves is known as the insertion. l Muscles always work in pairs, As they can only pull to create movement. (as one contracts the other relaxes) l

Skeletal muscles cont The muscles that cause the movement is called a prime mover or agonist. l Usually another muscle works in the opposite direction at the same time. This muscle is known as the antagonist muscle. l

Tendons Connective tissue refers to other features which support the body and its movement. Tendons are strong strips which attach the muscles to bones. When a muscle contracts to move a joint, it is the tendon which pulls on the bone.

Ligaments l Ligaments are strong bands which connect bones at the joint. They're elasticated to allow the movement of that joint, but are strong enough to stop movement outside the normal range.

Cartilage l Cartilage is a soft cushioning substance which covers the ends of the bones. It acts as a shock absorber and reduces the rubbing of the bone surfaces.