Q 66. How do parasympathetic neural signals affect the working of the heart? Option A Heart rate is increased without affecting the cardiac output. Option B Both heart rate and cardiac output increase. Option C Heart rate decreases but cardiac output increases. Option D Reduces both heart rate and cardiac output.
Q 66. How do parasympathetic neural signals affect the working of the heart? Option A Heart rate is increased without affecting the cardiac output. Option B Both heart rate and cardiac output increase. Option C Heart rate decreases but cardiac output increases. Option D Reduces both heart rate and cardiac output.

Correct Option: D

Solution: Post-ganglionic fibers of the parasympathetic nervous system secrete acetylcholine. This in return decreases the heart rate and cardiac output.