Most reflex arcs involve only three neurons. This characteristic allows reflex actions to occur relatively quickly by activating spinal motor neurons without the delay of routing signals through the brain, although the brain will receive sensory input while the reflex action occurs. In higher animals, most sensory neurons do not pass directly into the brain, but synapse in the spinal cord.
The path taken by the nerve impulses in a reflex is called a reflex arc.
A reflex does not require any thought input. When a person accidentally touches a hot object, they automatically jerk their hand away without thinking. \)Ī reflex action, also known as a reflex, is an involuntary and nearly instantaneous movement in response to a stimulus.