A person walks across a room in bare feet and puts his foot on a drawing pin lying on the floor. He lets out a cry. Explain what happens in his nervous system in bringing about this response.

Question

Philoid · Accepted Answer

This is an example of reflex action. Here, drawing pin lying on the floor is the stimulus. The receptors located in the skin sense pain which triggers and impulse in a sensory neuron and transmits the message to the spinal cord. The impulse is passed onto a relay neuron which passes it to the motor neuron which passes the impulse to a muscle in the feet. It results contraction of muscle and pulling out feet away from the drawing pin.