In a reflex action, receptor recognises the stimuli and generates the impulses which are carried by the sensory neuron to the spinal cord. The Relay neuron then connects the sensory neuron and the motor neuron and generates quick responses according to the sensory impulses. Motor neuron carries the information from the spinal cord to effector also known as the effector. As a response, the effector responds to the stimulus like withdrawing the hand when we touch a hot object.