HUMAN PHYSIOLOGY
BODY FLUIDS AND CIRCULATION
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Both heart rate and cardiac output increase.
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Heart rate decreases but cardiac output increases.
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Reduce both heart rate and cardiac output.
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Heart rate is increased without affecting the cardiac output
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Detailed explanation-1: -Parasympathetic neural signals ( a component of ANS) decrease the rate of heart beat, the speed of conduction of action potential and thereby the cardiac output.
Detailed explanation-2: -The parasympathetic nervous system (PNS) releases the hormone acetylcholine to slow the heart rate. Such factors as stress, caffeine, and excitement may temporarily accelerate your heart rate, while meditating or taking slow, deep breaths may help to slow your heart rate.
Detailed explanation-3: -Parasympathetic Stimulation Slows the Heart Rate by Decreasing the Slope of the Pacemaker Potential. Parasympathetic nerves to the heart originate from the vagal motor nuclei in the brainstem and travel over the vagus nerve (cranial nerve X) to the heart.
Detailed explanation-4: -Parasympathetic innervation is responsible for: reducing the heart rate. reducing the force of contraction of the heart. vasoconstriction (narrowing) of the coronary arteries.
Detailed explanation-5: -So the parasympathetic neural signals decreases the heart rate whereas the sympathetic neural signals increase the heart rate.