Answer:
contraction and relaxation of the heart
Explanation:
Well one it is true cuz it is true but ya your right ok
The patellar reflex or knee(j)erk reflex doesn't happen when your leg is straight because the tendon is relaxed. In order for the reflex to be elicited, the tendon must be flexed or stretched.
This is called homeostasis. Its the way the body keeps itself in check even if the environment is trying to harm it
3x +12. Look at the picture below for the explanation!
Hope this helps!
