Tag: cardiac cycle

Questions Related to cardiac cycle

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.

cardiac cycle simple nutrients into cells the circulatory system biology

  1. True

  2. False

Show answer
Correct Option: B
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'

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

cardiac cycle simple nutrients into cells the circulatory system biology

  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.

Show answer
Correct Option: A
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'.

What happens when the pacemaker becomes nonfunctional?

cardiac cycle simple nutrients into cells the circulatory system biology

  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

Show answer
Correct Option: C

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

cardiac cycle simple nutrients into cells the circulatory system biology

  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

Show answer
Correct Option: C
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.

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 

cardiac cycle simple nutrients into cells the circulatory system biology

  1. Purkinje fibres

  2. Under the clavicle

  3. Atrioventricular node

  4. Bundle of His

Show answer
Correct Option: B
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.

Purkinje system is spread in 

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

  1. Auricle myocardium

  2. Ventricle myocardium

  3. Both A and B

  4. None of the above

Show answer
Correct Option: B
Explanation:

Purkinje system is mainly present in the ventricle myocardium. They spread impulse in ventricles generated by the AV node.

So, the correct answer is option B.

Contraction of heart is 

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

  1. Diastole

  2. Systole

  3. Joint diastole

  4. None of the above

Show answer
Correct Option: B
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.

Frequency of cardiac cycle is described by 

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

  1. Systole

  2. Diastole

  3. Heart-rate

  4. Pulse

Show answer
Correct Option: C
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.

'Dupp' sound is produced during closure of

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

  1. Semilunar valves

  2. Bicuspid valve

  3. Tricuspid valve

  4. Both B and C

Show answer
Correct Option: A
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.

 Heart rate of man is mainly controlled by

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

  1. SA node

  2. Ventricles

  3. Purkinje fibers

  4. AV node

Show answer
Correct Option: A
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).