{B1} {The Nervous System} 2

ACTIONS:

Voluntary actions are under the conscious control of your brain, i.e you decide how to react to a stimulus. For example, tasting something bitter (stimulus) and spitting it out (response).

Reflex actions bypass your brain to give fast, automatic responses to a stimulus, to protect your body, e.g:  

• pupil reflex automatically controls light entering your eye, to prevent damage to the retina.
• knee jerk reaction. 
• automatically withdrawing your hand from a hot plate to prevent you from getting burned.

THE EYE: 

Your iris, controls the amount of light that enters your eye. The rays of…