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 evs respiration in organism human respiration the mechanism of breathing breathing and its movements

If a man from sea coast goes to Everest peak then

  1. His breathing and heart beat will increase

  2. His breathing and heart beat will decrease

  3. His respiratory rate will decrease

  4. His heart beat will decrease
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

(a) At high altitude, $PO _2$ of alveolar air falls because of low $O _2$ tension of tissues. So, $O _2$ is absorbed very quickly from alveoli, thus, increasing breathing rate. Heart beat also increases to supply required amount of O2 to tissues.



Multiple choice evs respiration in organism human respiration the mechanism of breathing breathing and its movements

Breathing rate can be measured by

  1. Heartbeat count

  2. Amount of blood

  3. Haemoglobin count

  4. None of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
The breathing rate can be measured by the heartbeat count. This is because the heart is connected to the lungs via the pulmonary artery. In a healthy person with the normal heartbeat, 60-100 per minute will have 12-20 breathes in a minute.
So the correct answer is 'Heartbeat count'.
Multiple choice physics pressure in liquids and gases common consequences of the atmospheric pressure atmospheric pressure and its consequences important points about atmospheric pressure

Find the ratio of a systolic blood pressure of $120$ (in mm of Hg) to atmospheric pressure. Standard atmospheric pressure is $1.01\times 10^{5}\ Pa$

  1. 0.16

  2. 1.6

  3. 16

  4. 160
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Systolic pressure is 120 mm Hg. Convert this to Pascals: P = h * d * g = 0.12 m * 13600 kg/m^3 * 9.8 m/s^2 = 15993.6 Pa. The ratio to standard atmospheric pressure (1.01 * 10^5 Pa) is 15993.6 / 101000, which is approximately 0.158, rounding to 0.16.

Multiple choice biology blood circulatory system of human cardiac cycle heart, blood vessels and cardiac cycle human heart

Contraction of heart is 

  1. Diastole

  2. Systole

  3. Joint diastole

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

Systole is defined as the ventricular contraction of heart which occurs between the first and second heart sounds of the cardiac cycle. There is pumping of blood into the aorta and pulmonary trunk and lasts for 0.3-0.4 second. During systole arterial blood pressure is maximum. 

Thus the correct answer is option B.

Multiple choice biology blood circulatory system of human cardiac cycle heart, blood vessels and cardiac cycle human heart

Frequency of cardiac cycle is described by 

  1. Systole

  2. Diastole

  3. Heart-rate

  4. Pulse
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The cardiac cycle refers to a complete heartbeat from its generation to the beginning of the next beat. The frequency of the cardiac cycle or the heart rate is expressed as heart beats per minute.

So, the correct answer is option B.

Multiple choice biology blood circulatory system of human cardiac cycle heart, blood vessels and cardiac cycle human heart

'Dupp' sound is produced during closure of

  1. Semilunar valves

  2. Bicuspid valve

  3. Tricuspid valve

  4. Both B and C
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

During each cardiac cycle two prominent sounds are produced, which can be easily heard through a stethoscope. The first heart sound (lubb) is associated with the closure of the tricuspid and bicuspid valves, whereas the second heart sound (dupp / dubb) is associated with the closure of the semilunar valves. These sounds are of clinical diagnostic significance.

Multiple choice biology blood circulatory system of human cardiac cycle heart, blood vessels and cardiac cycle human heart

 Heart rate of man is mainly controlled by

  1. SA node

  2. Ventricles

  3. Purkinje fibers

  4. AV node
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The cardiac cycle is regulated by specialized areas in the heart wall, that forms the conduction system of the heart. Two of these areas are tissue mass, called as nodes; the third is a group of fibers called as the atrioventricular bundle. 

The sinoatrial node, which is located in the upper wall of the right atrium and initiates the heartbeat, is called as the pacemaker. 
The second node, located in the interatrial septum at the bottom of the right atrium, is called as the atrioventricular node. 
The atrioventricular bundle, also known as the bundle of His, is located at the top of the interventricular septum. It has branches, that extend to all parts of the ventricle walls. Our heart normally beats 70-75 times in a minute (average 72 beats/min).

Multiple choice biology transport in animals cardiac cycle heart, blood vessels and cardiac cycle human heart

'Bundle of His' is a network of

  1. Muscle fibres distributed throughout the heart walls

  2. Muscle fibres found only in the ventricle wall

  3. Nerve fibres distributed in ventricles

  4. Nerve fibres found throughout the heart
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

'Bundle of His' is a network of muscle fibres, found in the walls of ventricles. They originate from AV node and further give rise to Purkinje fibres. This helps in maintaining the rhythmic contraction of the ventricles. 

Multiple choice biology transport in animals cardiac cycle heart, blood vessels and cardiac cycle human heart

The pace-setter in the heart is called as

  1. Purkinje fibres

  2. Sino-atrial node (SAN)

  3. Papillary muscle

  4. Atrio-ventricular node (AVN)
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The cardiac impulse is initiated in the sino-atrial node also known as natural pacemaker. It then travels to the atrio-ventricular node. From there through the Purkinje fibres to the ventricles. The atrio-ventricular node regulates the rhythm of the heart rate mainly. The delay in conduction of impulse in this node changes the duration of contraction between the atria and the ventricles. Hence AV node is called as the pace-setter.

Multiple choice biology transport in animals cardiac cycle heart, blood vessels and cardiac cycle human heart

Heart beat is accelerated by

  1. Sympathetic nerves and noradrenaline

  2. Cranial nerves and adrenaline

  3. Cranial nerves and acetylcholine

  4. Sympathetic nerves and acetylcholine
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A normal heart rate is 60 to 80 beats per minute. However, in certain conditions, the heart beat is accelerated. The major system involved in acceleration of heartbeat is sympathetic nervous system. It releases hormones like adrenaline and noradrenaline during stress or excitement. Exercise also stimulates sympathetic nervous system to accelerate the heartbeat. Apart from heartbeat, sympathetic nervous system and noradrenaline constricts blood vessels, goose bumps, sweating, increased blood pressure, dilation of pupil.

Thus, the correct answer is 'Sympathetic nerves and noradrenaline.'

Multiple choice biology transport in animals cardiac cycle heart, blood vessels and cardiac cycle human heart

Bundle of His is

  1. Nervous tissue supplying ventricles

  2. Nervous tissue supplying heart

  3. Muscular tissue supplying atria

  4. Muscular tissue supplying ventricles
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

A) Bundle of His is a muscular tissue.

B) Bundle of His is a muscular tissue that carries electrical impulses to the ventricles.
C) Bundle of His supplies to the ventricles.
D) The bundle of His is an important part of the electrical conduction system of the heart, as it transmits impulses from the atrioventricular node, located at the inferior end of the interatrial septum, to the ventricles of the heart. It is a muscular tissue.
So the correct answer is 'Muscular tissue supplying ventricles'.

Multiple choice biology transport in animals cardiac cycle heart, blood vessels and cardiac cycle human heart

When does the blood enter in Atria. Choose the correct:-
(a) During generation of impulse from SAN
(b) Atrial relaxation
(c) As the tricuspid and bicuspid valves are open 
(d)Joint diastole

  1. a,b

  2. a, b, c

  3. b, c, d

  4. all
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Heart has two ventricles and two atria, left and right respectively. Deoxygenated blood enters the left atrium through superior & inferior vena cava, when the atria relaxes, blood enters into it, whereas impulse from SA node causes contraction of atria which leads to the flow of blood into ventricles.

Thus, the correct answer is 'a,b.'