You are taking notes in lecture,writing as fast as you can,when suddenly your hand become so stiff that you can't write any more! You pull the pencil from between your frozen fingers with your other hand,and after a few worried moments your hand is able to relax again.What happened? A) The muscles in your hand depleted their supply of ATP, and the myosin heads could not detach from actin. B) The muscles in your hand depleted their supply of acetylcholinesterase. C) The muscles in your hand depleted their supply of Ca²⁺, and the myosin heads could not attach to actin. D) The actin and myosin filaments in your hand muscles became detached from their Z lines. E) The motor neurons stimulating your hand muscles depleted their supply of acetylcholine.

Question

Quizplus · Accepted Answer

When the muscles in the hand use up their supply of ATP, the myosin heads cannot detach from actin, leading to a stiffening of the muscle and the inability to contract or relax properly. This is known as rigor, and occurs after death or extreme muscle exhaustion.

You Are Taking Notes in Lecture,writing as Fast as You