Tag: cardiac cycle

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Questions Related to cardiac cycle

Multiple choice cardiac cycle simple nutrients into cells the circulatory system biology

State whether the following statements are true or false.
A  pacemaker is a tiny computerised electrical device that is implanted in -a patients body to regulate the brain activity.

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

A pacemaker is a tiny battery run instrument placed near to the heart of a patient for generation impulses similar to the SA node for the rhythmic functioning of the heart

So, the correct answer is 'False'

Multiple choice cardiac cycle simple nutrients into cells the circulatory system biology

Which of the following is the correct pathway for propagation of cardiac impulse?

  1. SA node $\rightarrow$ AV node $\rightarrow$ Bundle of His $\rightarrow$ Purkinje fibres
  2. AV node $\rightarrow$ Bundle of His $\rightarrow$ SA node $\rightarrow$ Purkinje fibres
  3. SA node $\rightarrow$ Purkinje fibres $\rightarrow$ AV node $\rightarrow$ Bundle of His
  4. Purkinje fibres $\rightarrow$ AV node $\rightarrow$ SA node $\rightarrow$ Bundle of His.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Cardiac impulse generates from SA node then it reaches to AV node, then to bundle of HIS and finally to Purkinje fibers, this is how the cardiac impulse is generated.

So, the correct option is 'SA node 
→→ AV node →→ Bundle of His →→ Purkinje fibers'.

Multiple choice cardiac cycle simple nutrients into cells the circulatory system biology

What happens when the pacemaker becomes nonfunctional?

  1. Only auricles contract rhythmically

  2. Only ventricles contract rhythmically

  3. Cardiac muscles do not undergo co-ordinated rhythmic movements

  4. Auricles and ventricles contract rhythmically
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

If the SA node fails, the heart loses its coordinated rhythmic contraction because the electrical signal is not initiated correctly, leading to arrhythmia.

Multiple choice cardiac cycle simple nutrients into cells the circulatory system biology

An artificial pacemaker is implanted subcutaneously and connected to the heart in patients

  1. Having 90% blockage of the three main coronary arteries

  2. Having a very high blood pressure

  3. With irregularity in the heart rhythm

  4. Suffering from arteriosclerosis
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Pacemaker serves to produce rhythmic impulses for the heart beat. The sinoatrial node (SA) node serves as a pacemaker and is a small mass of specialized cardiac muscle. It is present in the posterior wall of the right atrium near the opening of superior vena cava. 

When the natural pacemaker is defective, the heartbeat may be too fast, too slow or irregular. Artificial pacemakers are electronic devices that stimulate the heart with electrical impulses to maintain or restore a normal rhythm in people with slow heart rhythms. An artificial pacemaker provides an electrical impulse (discharge) that can stimulate the heart, thus restoring or maintaining a regular heartbeat. 
So, the correct answer is option C.

Multiple choice cardiac cycle simple nutrients into cells the circulatory system biology

The 'cardiac pacemaker' in a patient fails to function normally. The doctors find that an 'artificial pacemaker' is to be grafted in him. It is likely that it will be grafted at the site 

  1. Purkinje fibres

  2. Under the clavicle

  3. Atrioventricular node

  4. Bundle of His
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
Sinoatrial (SA) node is the natural pacemaker of the heart. It generates the nerve impulses needed for heart contraction. When the SA node stops functioning, an artificial pacemaker should be implanted for proper conduction of impulse.
The artificial pacemaker is implanted inside the skin under the clavicle. In this, a vein is incised with the insertion of electrode lead through the valve of heart.
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

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).