As physical activity slows, which nervous system division slows respiration and heart rate?

As physical activity slows, which nervous system division slows respiration and heart rate?

• A. Digestive system takes over
• B. Parasympathetic nervous system slows respiration and heart rate
• C. Sympathetic nervous system speeds up respiration
• D. Muscular system takes over

Answer: (B)

When activity slows, the body shifts toward the parasympathetic division of the autonomic nervous system, the rest-and-digest side that promotes conservation of energy and recovery. This division slows both heart rate and respiration so the body can restore and maintain functions like digestion more effectively. The parasympathetic system does this by signaling the heart and respiratory centers to reduce activity, often using the vagus nerve. The other options don’t fit because the digestive system isn’t a controlling pathway for slowing heart rate and breathing, even though parasympathetic activity can influence digestion. The sympathetic division, in contrast, speeds up heart rate and respiration during stress or exertion, which is opposite of what happens when activity slows. The muscular system isn’t a regulatory system for autonomic functions like heart rate and breathing.

When activity slows, the body shifts toward the parasympathetic division of the autonomic nervous system, the rest-and-digest side that promotes conservation of energy and recovery. This division slows both heart rate and respiration so the body can restore and maintain functions like digestion more effectively. The parasympathetic system does this by signaling the heart and respiratory centers to reduce activity, often using the vagus nerve.

The other options don’t fit because the digestive system isn’t a controlling pathway for slowing heart rate and breathing, even though parasympathetic activity can influence digestion. The sympathetic division, in contrast, speeds up heart rate and respiration during stress or exertion, which is opposite of what happens when activity slows. The muscular system isn’t a regulatory system for autonomic functions like heart rate and breathing.