Question

Write down the following in the correct order for a simple reflex arc :

(a) impulse travels in motor fibre

(b) impulse travels in sensory fibre

(c) effector organ stimulated

(d) impulse crosses synapse

Answer 1

The pathway taken by nerve impulses in a reflex action is called a reflex arc. It is an automatic response to a stimulus. When a stimulus is given to a receptor, the receptors produce an impulse in the sensory fibre. The sensory fibre carries this message in the form of an electrical stimulus across the synapse. From the synapse, the impulse travels in the motor fibre and stimulates the effector organ to produce the desired response.
The correct order for a simple reflex arc is:
(b) →(d) → (a) → (c).