Biology

Cardiovascular and Nervous System

983 Questions

Review the human cardiovascular system through these competitive exam practice questions. Key areas include heart valves, cardiac impulse pathways, and blood pressure regulation. A solid grasp of these fundamentals is crucial for science sections.

Heart anatomy and valvesCardiac impulse conductionBlood pressure mechanicsHeartbeat regulation

Cardiovascular and Nervous System Questions

Multiple choice biology transport in mammals regulation of the activity of heart drug, tobacco and alcohol consumption community health and hygiene

Parameter not affected by sympathetic stimulation of heart?

  1. Cardiac output

  2. Stroke volume

  3. Duration of cardiac cycle

  4. Involuntary nature of cardiac musculature
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The involuntary nature of cardiac muscles is the major quality that makes them contract and relax continuously without pausing or without experiencing any fatigue like the rest of the muscles of our body. The parasympathetic nervous system has effects antagonistic to those of the sympathetic nervous system. The parasympathetic stimulation oh cardiac muscles, however, cannot change the involuntary nature of the cardiac musculature.

So, the correct answer is 'Involuntary nature of cardiac musculature'.

Multiple choice biology transport in mammals regulation of the activity of heart drug, tobacco and alcohol consumption community health and hygiene

Which of the following can increase the rate of heart beat?
(A) Sympathetic neural signal 
(B) Parasympathetic neural signal 
(C)Adrenal medullary hormones 
(D) Vagus nerve
(E) Thyroxine hormone
(F) Acetylcholine

  1. A,C,E

  2. D,E,F

  3. A,C,D

  4. B,D,F
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Sympathetic neural signals, adrenal medullary hormones (like epinephrine), and thyroxine all increase heart rate. Parasympathetic signals and acetylcholine decrease heart rate, while the vagus nerve carries parasympathetic signals.

Multiple choice biology transport in mammals regulation of the activity of heart drug, tobacco and alcohol consumption community health and hygiene

The heart keeps on beating throughout the life without fatigue, because

  1. In contracts slowly.

  2. It has a long recovery period.

  3. It can use lactic acid as an extra source of energy.

  4. None of the above.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

A refractory period is a period of time during which an organ or cell is incapable of repeating a particular action. 

The refractory period in cardiac physiology is related to the ion currents that, in cardiac cells as in nerve cells, flow into and out of the cell freely. 
After an action potential initiates, the cardiac cell is unable to initiate another action potential for some duration of time. This period of time is referred to as the refractory period, which is 250 ms in duration and helps to protect the heart.

Multiple choice biology transport in mammals regulation of the activity of heart drug, tobacco and alcohol consumption community health and hygiene

If the vagus branch of frog is stimulated the heart will show

  1. Stoppage of heart beat

  2. Decreased heart beat

  3. Increased heart beat

  4. No change
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The tenth cranial nerve (X) is the vagus nerve. It is the longest cranial nerve. (Its name means "wanderer"). It supplies most of the organs in the thoracic and abdominal cavities. This nerve also contains motor fibers to the larynx (voice box) and pharynx, and to glands that produce digestive juices and other secretions. The vagus nerve is responsible for such varied tasks as heart rate, gastrointestinal peristalsis, sweating, and quite a few muscle movements in the mouth, including speech. Parasympathetic innervation of the heart is partially controlled by the vagus nerve and is shared by the thoracic ganglia. To be specific, vagal and spinal ganglionic nerves mediate the lowering of the heart rate. 

Multiple choice biology transport in mammals regulation of the activity of heart drug, tobacco and alcohol consumption community health and hygiene

Innervation of heart in the intact animals is primarily meant for

  1. Initiation of heart beat.

  2. Regulation of heart beat.

  3. Release of acetylcholine only.

  4. Release of Adrenalin only.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Heart beat is initiated by the nodal cells of the SA node. It starts the heart beat. The electrical impulse is then carried by the nerves to the AV node and the Purkinje fibres. Thus the nerves help to spread the impulse throughout the heart. Hence the rate and rhythm of heart beat is controlled by the impulses travelling through the nerves.

Multiple choice biology transport in mammals regulation of the activity of heart drug, tobacco and alcohol consumption community health and hygiene

Which of the following hormone regulates the cardiac activity?

  1. Epinephrine

  2. Parathrome

  3. Thymosine

  4. None of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The cardiac activity is controlled by the sympathetic nervous system through the epinephrine. It fastens the heartbeat and the cardiac output so that more concentration of oxygen can be supplied to the body parts.

A. Epinephrine regulates the cardiac activity.
B. Parathormone is released by the parathyroid gland and is involved in calcium balance mechanism.
C. Thymosin is released by the thymus gland and it is involved in maturation of the T-cells.
Hence, the correct answer is 'Epinephrine'

Multiple choice biology transport in mammals regulation of the activity of heart drug, tobacco and alcohol consumption community health and hygiene

Heart beat is accelerated by

  1. Sympathetic nerves and acetylcholine

  2. Cranial nerves and adrenaline

  3. Cranial nerves and acetylcholine

  4. Sympathetic nerves and epinephrine.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Sympathetic nerves release norepinephrine and stimulate the adrenal medulla to release epinephrine, both of which accelerate the heart rate. Acetylcholine is a parasympathetic neurotransmitter that slows the heart rate.

Multiple choice biology transport in mammals regulation of the activity of heart drug, tobacco and alcohol consumption community health and hygiene

Which term does not apply to human heart?

  1. Neurogenic

  2. Pacemaker

  3. Few chambered

  4. Mitral valve
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
A neurogenic heart is the one in which impulses are originated by nerves. This type of heart is present in cockroach and some invertebrates. Human heart is myogenic which means that impulses are originated by muscles. 
The SA node in human heart is called pacemaker as it initiates and maintains the rhythmic contraction of heart. 
Human heart is four chambered consisting of 2 auricles and 2 ventricles. 
Mitral valve is also known as bicuspid valve and present between left atrium and left ventricle. 
Hence, neurogenic heart does not apply to human heart.
So, the correct answer is 'Neurogenic'.
Multiple choice biology transport in mammals regulation of the activity of heart drug, tobacco and alcohol consumption community health and hygiene

Regarding circulatory adjustments during exercise which of the following is correct?

  1. The cardiac output increases more than tenfold in severe exercise.

  2. The increase in cardiac output during exercise is mainly due to an increase in stroke volume.

  3. The increase in stroke volume seen in exercise occurs despite a smaller and end - diastolic volume.

  4. In sever exercise the mean arterial pressure is unchanged because diastolic pressure.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Cardiac output is the product of heart rate and stroke volume. During exercise, both increase significantly to meet oxygen demand, with the increase in stroke volume being a primary contributor to the rise in cardiac output.

Multiple choice biology transport in mammals regulation of the activity of heart drug, tobacco and alcohol consumption community health and hygiene

Read the following statements and select the correct ones.


(i) Nodal tissue is specialised cardiac musculature in human heart which has the ability to generate action potential.
(ii) Position of SA Node - right corner of right atrium
(iii) Position of AV Node - right corner of ventricle
(iv) AV bundle continues from AV Node
(v) Purkinje fibres are modified cardiac muscle fibres that originate from the atrioventricular node and spread into the two ventricles.

  1. (i) and (ii)

  2. (i), (ii) and (iv)

  3. (ii), (iv) and (v)

  4. All of these
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Statement (i) is correct because nodal tissue generates action potentials. Statement (ii) is correct because the SA node is located in the upper right corner of the right atrium. Statement (iv) is correct as the AV bundle continues from the AV node. Statement (iii) is incorrect because the AV node is located in the lower left corner of the right atrium near the AV septum, not in the ventricle. Statement (v) is incorrect because Purkinje fibers emerge from the bundle of His, not directly as the sole origin from the AV node without the bundle.

Multiple choice biology transport in mammals regulation of the activity of heart drug, tobacco and alcohol consumption community health and hygiene

Consider the following four statements (i) - (iv) and select the correct option.
(i) Fish heart contains only oxygenated blood.
(ii)Closure of A-V valves produces the second heart sound.
(iii) The vascular connection between the digestive tract and kidney is called hepatic portal system.
(iv) Purkinje fibres are nerve fibres present in the heart wall.

  1. i - F, ii - F, iii - T, iv - F

  2. i - F, ii - F, iii - F, iv - T

  3. i - T, ii - T, iii - F, iv - T

  4. i - T, ii - F, iii - T, iv - F
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

  • The fish heart contains both oxygenate and deoxygenated blood as it has one atrium and one ventricle.
  • Closure of A-V valves produces the first heart sound.
  • The vascular connection between the digestive tract and the liver is called the hepatic portal system.
  • Purkinje fibres are nerve fibres present in the heart wall.
Thus, the correct answer is 'i - F, ii - F, iii - F, iv - T.'

Multiple choice biology transport in mammals regulation of the activity of heart drug, tobacco and alcohol consumption community health and hygiene

Which of the following statements is correct regarding neural regulation of cardiac activity?

  1. The cardiac centre lies in medulla oblongata of brain.

  2. Sympathetic nerve fibres accelerate the rate of heart beat and parasympathetic nerve fibres retard the rate of heart beat.

  3. Sensory fibres extend from the receptors present in the walls of aortic arch, carotid sinuses and vena cava to the cardiovascular centre in medulla oblongata.

  4. All of these
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

  • The medulla oblongata of the brain controls cardiac activities.
  • The action of sympathetic nerve fibres increases the heart rate, while that of the parasympathetic nerve fibres decrease it.
  • Sensory fibres extend from the receptors present in the walls of the aortic arch, carotid sinuses and vena cava to the cardiovascular centre in the medulla oblongata.
Thus, the correct answer is 'All of these.'

Multiple choice biology transport in mammals regulation of the activity of heart drug, tobacco and alcohol consumption community health and hygiene

The problem of electrical discontinuity caused in the normal heart by the connective tissue separating the atria from the ventricles is solved by

  1. Coordinating electrical activity in the atria with electrical activity in the ventricles by connecting them via the bundle of His

  2. Having the A-V node function as a secondary pacemaker

  3. Having an ectopic pacemaker

  4. Coordinating electrical activity in the atria with electrical activity in the ventricles by connecting them via the vagus nerve.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The fibrous connective tissue skeleton separates the atria from the ventricling, preventing direct electrical propagation between them. This electrical discontinuity is bridged by the atrioventricular bundle, commonly known as the bundle of His, which transmits the action potential from the atria down to the ventricles.

Multiple choice biology transport in mammals regulation of the activity of heart drug, tobacco and alcohol consumption community health and hygiene

Cardiac activity could be moderated by the autonomous neural system. Tick the correct answer.

  1. The parasympathetic system stimulates heart rate and stroke volume.

  2. The sympathetic system stimulates heart rate and stroke volume.

  3. The parasympathetic system decreases the heart rate but increase stroke volume.

  4. The sympathetic system decreases the heart rate but increase stroke volume.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Cardiac activity could be moderated by the autonomous neural system. The action of sympathetic nerve fibres increases the heart rate and the stroke volume, while that of the parasympathetic nerve fibres decrease these.

Thus, the correct answer is 'The sympathetic system stimulates heart rate and stroke volume.'