7.1 Getting moving

7.1- getting moving

Joints and movements 

• Muscles are used to move a joint, normally several per joint.

• Muscles can only pull not push. So there has to be at least two muscles per joint to move it in both directions.

• Two muscles working together are known as an antagonistic.

• a muscle that contract to cause the leg to extend (A) is known as an extensor. A muscle that causes the joint to bend (B) is called the flexor.

Joint Structure

• The hip, knee and ankle joints are known as synovial joints, the bones that move are separated by synovial fluid.

• The bones in a synovial joint are held in place by ligaments that control the amount of movement.

• Tendons join the muscle a bone and alow the muscle to power the movement.

• Cartilage protects the bone.

Muscles

• Muscles are made of bundles of muscle fibres, each fibre is a muscle tissue.

• They are several cm long and have multiple nuclei - multinucleate. This is because one nucleus could not control the metabolism of such a long cell. They are formed in prenatel development when several cells fuse together.

Inside…