Answer: 1
Step-by-step explanation:
When the receptor(sensory neuron) is stimulated, it sends a message to a part of your body that effects the correct response. This is called the effector(motor neuron.
Receptor in the skin detects a stimulus (pain, the change in temperature).
Motor neuron sends electrical impulses to an effector.
Effector produces a response makes muscle contracts to move hand away.
For example, keeping hold of a hot object requires a nerve impulse to be sent to the motor neuron of the reflex arc to interfere with the normal reflex action to drop the object.