Tag: biology

Questions Related to biology

If a person is undergoing artificial pacemaker transplant then at which of the following structure the transplantation occurs?

cardiac cycle simple nutrients into cells the circulatory system biology

  1. SA node

  2. AV node

  3. SA bundles

  4. Right ventricle

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Correct Option: A
Explanation:
  • Heart's sinus node (SA node) is our natural pacemaker (located in the upper right chamber of the heart).
  • It sends an electrical impulse to produce the heartbeat.
  • The job of a pacemaker is to artificially take over the role of your sinus node if it isn't working properly.
  • So, the correct answer is 'SA node'.

Natural pacemaker of heart is?

cardiac cycle simple nutrients into cells the circulatory system biology

  1. SA node or Sinuatrial node

  2. AV node or Auriculoventricular node

  3. Helpful in initiation of cardiac impulse

  4. Both $(1)$ & $(3)$ are correct

Show answer
Correct Option: A

Which of the following is called pacemaker?

cardiac cycle simple nutrients into cells the circulatory system biology

  1. AV node

  2. Bundle of His

  3. SA node

  4. Purkinje fibres

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Correct Option: C
Explanation:

The heart muscle's electrical impulses cause the heart to beat. This electrical signal starts at the Sinoatrial (SA) node at the top of the upper-right chamber of the heart. Sometimes the SA node is called the "natural pacemaker" of the heart.The SA node sends electrical impulses at some level, but depending on physical requirements, stress, or hormonal variables, heart rate may still alter.  It causes the upper chambers of the heart (the atria) to contract when an electrical impulse is released from this natural pacemaker. Then the signal travels to AV node and then to the bundle of HIs resulting in ventricular contraction.

So, the correct answer is 'SA node'

Where is the pacemaker situated?

cardiac cycle simple nutrients into cells the circulatory system biology

  1. In left auricle near opening of pulmonary vein

  2. In right auricle near eustachian valve

  3. On inter-auricular septum

  4. On inter-ventricular septum

Show answer
Correct Option: B
Explanation:

Sino-atrial node is the natural pacemaker of the heart. These are a group of small, flattened and ellipsoid strip cardiac muscle fiber situated in the upper lateral wall of the right atrium near the Eustachian valve (valve of the inferior vena cava).

So, the correct answer is option B.

Pacemaker influences

cardiac cycle simple nutrients into cells the circulatory system biology

  1. Contraction of heart muscles

  2. Flow of blood in heart

  3. Rate of heart beat

  4. Formation of nerve impulse

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Correct Option: A
Explanation:

A specialised cardiac musculature, called as the nodal tissue is distributed in the heart. A patch of this tissue is present in the right upper corner of the right atrium, called as the sino-atrial node (SAN). 

The nodal musculature has the ability to generate action potentials without any external stimuli, i.e., it is auto excitable. The SAN can generate the maximum number of action potentials, i.e., 70 - 75 beats/min and is responsible for initiating and maintaining the rhythmic contractile activity of the heart. Therefore, it is called as the pacemaker of heart.

The heartbeat is regulated by a small node of cardiac muscles called

cardiac cycle simple nutrients into cells the circulatory system biology

  1. Pericardium

  2. Ventricle

  3. Tricuspid valve

  4. Pacemaker

Show answer
Correct Option: D
Explanation:

A small node of specialized tissue is located int he upper right corner of right ventricle called as SA node. It is known as natural pacemaker of heart as it is responsible for initiation and regulation of heart beat. 

In the heart of frog, which of the following is considered as the pacemaker?

cardiac cycle simple nutrients into cells the circulatory system biology

  1. Pylangium

  2. Synangium

  3. Truncus

  4. Sinus venosus

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Correct Option: D
Explanation:

In amphibians, such as the frog, the pacemaker is the sinus venosus, an enlarged region between the vena cava and the right atrium. The venae cavae do not open directly into the auricles but into another chamber, the sinus venosus, which drains into the right auricle. 

In which of the following pairs, the two items mean one and the same thing?

cardiac cycle simple nutrients into cells the circulatory system biology

  1. Malleus - Anvil

  2. SA node - Pacemaker

  3. Leucocytes - Lymphocytes

  4. Haemophilia - Lung cancer

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Correct Option: B
Explanation:

Malleus is hammer like bone of the middle ear. 

SA node is called as pacemaker of the heart that sets the beat. 
Leucocytes are WBCs and lymphocytes are B and T cells. 
Hemophilia is a blood disorder.
Therefore, the correct answer is option B.

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:
An artificial pacemaker is implanted subcutaneously and connected to the heart in patients with irregularity in the heart rhythm. It is implanted in the region of SA node which regulates the heartbeat. Sinoatrial node is known as the pacemaker of the heart. It helps in the generation and conduction of heartbeat. It is located in the walls of the right atria just below the opening of superior vena cava. The sympathetic nerves release the neurotransmitters and activate the SA node and generate electric impulse which is conducted as heartbeat throughout the heart. 
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 of

cardiac cycle simple nutrients into cells the circulatory system biology

  1. Sinoatrial node

  2. Atrioventricular node

  3. Atrioventricular bundle

  4. Purkinje system

Show answer
Correct Option: A
Explanation:

Sinoatrial node is known as pacemaker of the heart. It helps in the generation and conduction of heart beat. It is located in the walls of the right atria just below the opening of superior venacva. The sympathetic nerves release the neurotransmitters and activates the SA node and generates electric impulse which is conducted as heart beat through out the heart. 

When the cardiac pacemaker in a patient fails to function normally a artificial pacemaker is implanted at the site of SA node. It is a medical device which uses electrical impulse, generated by electrodes to contract the heart muscles, and regulate the heart beat.
So, the correct answer is option A.