Reflex action is an immediate involuntary response to a stimulus. In an involuntary response, a sensory impulse on reaching central nervous system is itself returned to a specific effector as a motor impulse without neuronal analysis and integration. Reflex responses occur below the level of consciousness. Reflex actions are sudden and autonomic. For instance, if ones foot is trickled the leg is drawn at once and this will happen even when one is busy in other activities upon which all the attention is concentrated and perhaps without even being conscious of the irritation. Therefore, we can say that reflex actions are those actions which result from the conversion of sensory impulses into motor impulse by a nerve center, like spinal cord, without the intervention of brain. Some common examples of reflex actions are:
The knee jerk reflex, when tendon of the knee cap is tapped, it stimulates the stretch receptors in the tendon and leg is involuntarily and momentarily straightened.
The quick closing of the eyelids or blinking reflex, when an object approaches the eye.
Sneezing reflex in response to irritation of lining of nose.
RAS PDF and Printed Notes for RAS Prelims and Mains Exam
