- Cartilage: a tissue made from collagen, which protects bone ends
- A muscle: an organ that produces movement by contraction
- A joint: the junction between two bones
- A tendon: joins muscle to bone
- A ligament: joins bone to bone to stabilise a joint
Muscles work in pairs. One muscle produces the opposite movement from the other muscle, therefore, the pairs are called antagonistic pairs.
Muscles which cause a joint to extend are called extensors, muscles which cause a limb to retract are called flexors.
A Synovial Joint
