What are the primary effects of the parasympathetic nervous system?

What are the primary effects of the parasympathetic nervous system?

• A. Fight-or-flight response.
• B. Rest-and-digest, including decreased heart rate and increased gastrointestinal motility.
• C. Increased heart rate and respiratory rate.
• D. Pupillary dilation.

Answer: (B)

The parasympathetic system drives a rest-and-digest state, focusing on conserving energy and promoting digestion. Its hallmark is slowing down metabolic activity in many organs while enhancing digestive processes. So, a primary effect is a decrease in heart rate, which reduces cardiac workload, combined with increased gastrointestinal motility to promote digestion. Neurotransmission uses acetylcholine at both the ganglia and the target organs, and this system is often described as craniosacral in origin. The other described effects—fight-or-flight activation, rising heart and respiratory rates, and pupil dilation—belong to the sympathetic system, which does the opposite of the parasympathetic actions.

The parasympathetic system drives a rest-and-digest state, focusing on conserving energy and promoting digestion. Its hallmark is slowing down metabolic activity in many organs while enhancing digestive processes. So, a primary effect is a decrease in heart rate, which reduces cardiac workload, combined with increased gastrointestinal motility to promote digestion. Neurotransmission uses acetylcholine at both the ganglia and the target organs, and this system is often described as craniosacral in origin.

The other described effects—fight-or-flight activation, rising heart and respiratory rates, and pupil dilation—belong to the sympathetic system, which does the opposite of the parasympathetic actions.