- Framework for muscle attachment
Insects have an external skeleton - This is made of Chitin and creates a protective covering. Hard covering can restrict growth and need to shed an old one and a new one is grown.
Some animals have an internal skeleton - Made of cartilage which is still found at the tip of your nose for example. This is a living tissue and has a framework of connections with other systems in the body such as joints, muscles and blood vessels.
Structure of a Long Bone:
- The head is covered with smooth cartilage
- Shaft is hollow