Functions of the skeleton
Six functions
The skeleton does six jobs. For each, the exam expects an example from sport.
| Function | What it means |
|---|---|
| Gives the body its shape and holds organs and muscles in place | |
| Holds the body upright and in position | |
| Surrounds and guards the vital organs | |
| Movement | Bones act as levers that muscles pull on |
| Blood cell production | Bone marrow makes red and white blood cells |
| Bones store minerals, such as calcium and phosphorus |
Remember
Six functions: Support, Posture, Protection, Movement, Blood cells, Minerals.
Key terms
Support, posture and protection
- the femur and tibia carry the body's weight when a sprinter drives out of the blocks.
- the vertebral column keeps a gymnast's body straight and aligned in a handstand, and keeps an archer upright and still while aiming.
- the protects the brain when a footballer heads the ball; the and protect the heart and lungs when a rugby player is tackled; the surround and protect the spinal cord.
Key terms
Movement
Bones meet at joints, and muscles are attached to them by . When a muscle contracts, it pulls on a bone, and the bone moves at the joint like a lever.
Example: when a hockey player hits the ball, muscles in the arm and shoulder pull on the humerus, radius and ulna to swing the stick. When a wheelchair basketball player pushes the wheels, muscles pull on the arm bones to straighten the elbows.
Without bones to pull on, muscles could not produce movement.
Blood cell production and storage of minerals
- Blood cell production: the inside some bones, such as the ribs, sternum, pelvis and the ends of the femur, makes red blood cells, which carry oxygen, and white blood cells, which fight infection. More red blood cells help a long-distance runner deliver more oxygen to the working muscles.
- bones store minerals such as calcium and phosphorus, and release them into the blood when the body needs them. Calcium keeps bones strong, so they're less likely to break in contact sports such as rugby, and is also needed for muscles to contract.