Describe how the sympathetic and parasympathetic nervous systems work together t

Human autonomic nervous system is divided into sympathetic and parasympathetic nervous systems.Sympathetic activity predominates at stress conditions and Parasympathetic activity at rest.
So it is obvious that both these systems are involved in controlling the heart rate.
We know that our heart beat is very fast and high when we are doing exercises,frightened, or when we are excited due to seeing something unexpectedly.The raise of heart beat at these times are done by the sympathetic nervous system.
And when we calm down and come back to normal our heart beat lowers and become slow.This slowing is done by the parasympathetic nervous system.
So,this is how these two systems take part in controlling the heart  rate.
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