Question

Describe reflex action and reflex arc.

Answer 1

• REFLEX ACTION: A reflex, or reflex action, is an involuntary and nearly instantaneous movement in response to a stimulus. A reflex is made possible by neural pathways called reflex arcs which can act on an impulse before that impulse reaches the brain.
• Examples include When light acts as a stimulus, the pupil of the eye changes in size. Coughing or sneezing, because of irritants in the nasal passages. Knees jerk in response to a blow or someone stamping the leg

• REFLEX ARC: Reflex arc is the nerve pathway involved in a reflex action, including at its simplest a sensory nerve and a motor nerve with a synapse between.
• Reflex arc consist of 1)Receptor or sensory organ, 2)Sensory neurine, 3)Reflex centre(brain or spinal cord), 4)Motor neurone and 5)Effector(muscle or gland).