CBSE Class 10 Answered

In a reflex arc, when the receptor detects the stimulus, it excites a sensory neuron. The message travels

through the sensory neuron to an interneuron in the central nervous system and then through the

interneuron to a motor neuron. The message travels through the motor neuron to the effector. The effector is stimulated and its reaction is the response. Thus nerve cells (neurons) carry the message from the stimulated receptors to the correct effectors. In nerve cells, impulses travel only from the axon of one neuron to the dendrites of the other neuron. Reflex arcs are made of neurons and hence the impulses flow in one direction only in a reflex arc