The pathway of nerve impulse involved in the reflex action is said to be "Reflex arc".

Reflex arc has 5 components. They are:-
a) Receptors
b) Sensory neuron
c) Relay neuron
d) Motor neuron
e) Effectors

a) Receptors: It receives stimulus.
Example:- Sense organs.

b) Sensory neuron: It carry the impulse to the spinal
cord.

c) Relay neuron: It processes information and transfer
to motor neuron.

d) Motor neuron: It carry impulse to muscles.

e) Effectors: It shows the visible action.
Example:- Muscles , Glands.

The reflex arc describes the pathway in which the nerve impulse is carried and the response is generated and shown by the effector organ.

The reflex arc typically consists of five components:

1. The receptor is present in the receptor organ.

2. The sensory neuron conducts the nerve impulses towards the central nervous system (CNS). The CNS is comprised of the brain and the spinal cord.

3. The information is transferred from one neuron to other.

4. A motor neuron conducts the response nerve from the CNS to the effector organ.

5. The effector organ shows response by contracting or secreting a product.

The instant movement performed by the individual in response to the stimulus is known as a reflex action.