The effector is going to be our muscles. So the control center sends an effrent signal to the muscles and says, our time to contract. Relax. Contract, relax, contract, relax, which is shivering. Why do we do that when we old? Because when muscles contract and relax, they relase heat and you warm up. And again, the outcome from the effector was the opposite of the stimulus. We've just provided through temperature, probably a very common example, two common examples of negative fade back. That's pretty good. Now, i just want to throw away the ladder. I just want tothrow a really quick one in here, just as a second