Describe the process of a simple reflex action (6marks)

Receptors in the skin which are sensitive to changes in pain, pressure and temperature detect a change in one of these factors. This acts as the stimulus for the reflex response. This stimulus triggers an electrical impulse which is carried initially by a sensory neurone to a synapse where the chemical information is transferred to a relay neurone and then across another synapse to a motor neurone. The motor neurone directs the impulse to an effector which is often a muscle. A response is brought about when the muscle contracts in response and this is the reflex action.