Answer :
Answer: Option A
Explanation: The cardiovascular system is the system of human body which circulates blood through the complete body to supply oxygen to the whole body.
It also carries nutrients along with the blood and carries waste materials from the body to the heart.
Heart rate can be defined as the number of times the heart beats per minute and it is related to the load the heart has.
The sympathetic nervous system of the body releases hormone like epinephrine, nor epinephrine which increases the heart rate. There are many other factors that increase the heart rate such as exercise, stress et cetera.
The cardiovascular system comprises the heart and circulates blood through the tissue of the body to supply oxygen-rich blood. Sympathetic innervation of the heart raises the heart rate.
What is sympathetic innervation?
The nerves from the autonomous and the sympathetic systems of the brain innervate the heart and affect the heart rate. The sympathetic nervous system raises the heart rate, whereas the parasympathetic decreases it.
The sympathetic nervous system releases norepinephrine enzymes that are a neurotransmitter at the junction of the nerves of the cardiac muscles. This causes increased contraction and heart rate.
Therefore, option a. heart rate is increased is correct.
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