"Reflex arc is a specialized type of neuron pathway. The reflex arc is like a one-way street and is used a defensive mechanism. You pull your hand away from a flame not because you consciously think to do it, but because the ANS system senses danger and immediately reacts. The reflex arc has three separate pathways. The one way street, then the two way street using sensory and motor neurons, and finally the three way street using sensory, motor, and interneurons."