1. How many bones did your model need? How many muscles did it need?
2. How were your pretend muscles similar to real muscles? Different?
3. What changes occur to the real muscles in the human body to make them pull on bones?
4. What would happen if the ligaments of the models were overstretched or torn? How would it affect the way the models could operate?
1. Technically our model needed 4 bones but because we didn't have a ton of materials we only used 2 bones. We used 2 muscles though. The bicep is the red balloon stretched on the top and the tricep is the red balloon stretched onto the bottom.
2. Our muscles were similar to real muscles because when you flex your arm you bicep relaxes and your tricep tightens. When you put your arm back down your bicep tightens and your tricep relaxes.
3. When muscles pull on bones they relax and tighten/contract. Like I said in the last answer when you flex your arm your bicep relaxes and your triceps tightens, when you put your arm back down it does the opposite.
4. If the ligaments tore then we couldn't move our arms. The model wouldn't work the right way.