Final answer:
The sympathetic system activates the 'fight or flight' response, while the parasympathetic system activates the 'rest and digest' response.
Step-by-step explanation:
The sympathetic and parasympathetic nervous systems are two divisions of the autonomic nervous system that act on the central nervous system (CNS) and nerves. The sympathetic system activates the 'fight or flight' response, which prepares the body for action in stressful situations. It increases heart rate, dilates airways, and redirects blood flow to muscles. On the other hand, the parasympathetic system activates the 'rest and digest' response, which promotes relaxation and digestion. It slows heart rate, constricts airways, and increases digestion.