What happens when your hand touches a flame?

You will will automatically move your hand away in a process known as the relex arc. Your natural 'reflex'.thermal sensors in your fingers will sense the heat and send electrical impulses along your sensory neurones. The electrical impulses are then sent along your relay neurones and to your motor neurones. The electrical impulses are sent down your motor neurones to muscles in your arms, which act as the effector, and the response is to remove your hand from the flame.