Question

If parasympathetic nerve of the rabbit is cut, then heart beat

• A. Remains unaffected
• B. Decreases
• C. Increases
• D. Stops

Answer 1

The correct option is C Increases

If parasympathetic nerve of the rabbit is cut, the most immediate effect would be an increase in heart rate. Also, the regulation of heart rate, contractile state, and conduction of electrical impulses through the heart would be impaired. The reason for the observed effects is that the vagus nerve carries important information to the heart from a part of the central nervous system called the parasympathetic nervous system. The parasympathetic nervous system is often considered the "rest and digest" system. It decreases heart rate, decreases how strongly the heart contracts with each beat, and decreases the rate at which electrical impulses are conducted through the heart.