Question

Heart beats are accelerated by
A. Cranial nerves and acetylcholine
B. Sympathetic nerves and acetylcholine
C. Cranial nerves and adrenaline
D. Sympathetic nerves and epinephrine

Answer 1

A resting heart rate of $60$ to $100$ beats per minute is recommended for adults.
A lower resting heart rate, in general, suggests improved cardiac function and cardiovascular fitness.
A heart rate of more than $100$ beats per minute is referred to as tachycardia. A multitude of heart rhythm abnormalities can induce tachycardia (arrhythmias). It's normal to have a fast heartbeat now and then.

Complete answer:
Option A: The cranial nerves have sensory, motor, or mixed functions: A person's sensory cranial nerves allow them to see, smell, and hear. Muscle movements in the head and neck are controlled by motor cranial nerves.
So option A is not correct.
Option B: A healthy heart rate is between 60 and 80 beats per minute. The heart rate, on the other hand, can be accelerated in certain circumstances. The sympathetic nervous system is the main system involved in heartbeat acceleration. During times of stress or excitement, it releases hormones such as adrenaline and noradrenaline.
So option B is not correct.
Option C: Adrenaline's main effects include boosting heart rate, blood pressure, expanding lungs' air passageways, enlarging the pupil in the eye, shifting blood to muscles, and changing the body's metabolism to maximise blood glucose levels.
So option C is not correct.
Option D: The sympathetic and parasympathetic chains of the autonomic nervous system control involuntary actions. During fight, flight, or fright, the sympathetic nerve chain speeds up the heartbeat. The adrenal medulla releases epinephrine, often known as adrenaline, into the bloodstream when sympathetic nerves are activated, increasing heart rate.It regulates the function and secretion of numerous organelles by binding to adrenergic receptors on their membranes. It binds to the heart's beta-adrenergic receptors and activates the SA node, causing the heart rate to rise.

So option D is the correct answer.

Note:
Epinephrine is a hormone produced by sympathetic fibres in the adrenal medulla in reaction to stress. Because the gland rests atop the kidney, the name epinephrine comes from epi, which means above, and nephros, which means kidney.
Norepinephrine is also known as noradrenaline, while epinephrine is also known as adrenaline. Both of these compounds play a function in the sympathetic nervous system's regulation, which is the part of the autonomic nervous system in charge of the body's "fight or flight" reaction.