Our model needed two each of bones and muscles. One of the bones represented the humerus, and the other represented the ulna and radius. One muscle represented the biceps, and the other represented triceps.
- How were your pretend muscles similar to real muscles? Different?
Our pretend muscles were made of one deflated balloon. This is similar to a real muscle because it is made up of soft, movable cells like muscles. It is different because it is just one component of muscle, instead of two or three, like the real muscle.
- What changes occur to the real muscles in the human body to make them pull on bones?
There are two ways it could happen. 1) The body part sends a message to the brain that it needs to move, and the brain sends a message to that muscle to tell it to move (involuntary movement), or 2) The brain sends a message to the muscle to move (voluntary movement).
- What would happen if the ligaments of the models were overstretched or torn? How would it affect the way the models could operate?
If a ligament was overstretched, it might allow the ball, or joint, to flop around between the paper towel tubes, or bones, and bones couldn't roll against the ball as easily if it is moving. If one was torn, the joint might fall out from between the bones. It is obvious why the joint couldn't operate this way.