If the vagal nerves to the heart were cut, the result would be that ________.
A) the heart would stop, since the vagal nerves trigger the heart to contract
B) the heart rate would increase by about 25 beats per minute
C) the AV node would become the pacemaker of the heart
D) parasympathetic stimulation would increase, causing a decrease in heart rate

Question

Quizplus · Accepted Answer

Cutting the vagal nerves would remove parasympathetic tone, resulting in an increase in heart rate by about 25 beats per minute. The heart would not stop beating because it has an intrinsic pacemaker in the form of the SA node, which would continue to beat at its own inherent rate. The AV node also has pacemaker properties, but it typically only takes over if the SA node fails to generate impulses. Removing vagal tone would not cause an increase in parasympathetic stimulation.

If the Vagal Nerves to the Heart Were Cut, the Result