A reflex is an involuntary, or automatic, action that your body does in response to something — without you even having to think about it.
<u>Animal Responses to External Stimuli</u>
Animals must react to changes in their external environment in order to survive. If a reaction is immediate and involuntary, the response is called a reflex reaction. Blinking the eyes in response to sunlight is an example of a reflex reaction.
When an injury occurs to the pons, midbrain and medulla oblongata, the consequences can be devastating. Heartbeat and breathing can cease, causing death.