Tag: cardiac cycle

Questions Related to cardiac cycle

Pacemaker is situated in the

cardiac cycle simple nutrients into cells the circulatory system biology

  1. Wall of right atrium

  2. Interauricular septum

  3. Interventricular septum

  4. Wall of left atrium

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Correct Option: A
Explanation:
The actual structure that serves as the heart's primary pacemaker is called the sinoatrial node (SA node). The SA node is a little bundle of cells located in the wall of the right atrium, the small upper chamber on the right side of the heart.
Thus, the correct answer is 'Wall of right atrium.'

The pacemaker of heart is

cardiac cycle simple nutrients into cells the circulatory system biology

  1. Foramen ovale

  2. Sinoatrial node

  3. Ductus arteriosus

  4. Bundle of His

  5. Vagus nerve

Show answer
Correct Option: B
Explanation:

Electrical impulses from the heart muscle cause your heart to beat (contract). This electrical signal begins in the sinoatrial (SA) node, located at the top of the heart's upper-right chamber (the right atrium). The SA node is sometimes called the heart's“natural pacemaker.”

So, the correct option is 'Sino-atrial node'.

Rate of heart beat is determined by

cardiac cycle simple nutrients into cells the circulatory system biology

  1. Purkinje fibres

  2. Papillary muscles

  3. AV-node

  4. SA-node

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Correct Option: D

The heart beat is initiated and regulated by nodal tissue made of specialised cardiac muscles called

cardiac cycle simple nutrients into cells the circulatory system biology

  1. Spongy tissue

  2. Purkinje tissue

  3. Alveolar tissue

  4. None of these

Show answer
Correct Option: B
Explanation:

Purkinje tissue is influenced by electrical discharge from the sinoatrial node. During the ventricular contraction portion of the cardiac cycle, the Purkinje fibres carry the contraction impulse from both the left and right bundle branch to the myocardium of the ventricles. In this way these fibres control and initiate heart beat.

So, the correct option is B. ( Purkinje tissue )

The action potential is conducted from the atria to ventricles by:

cardiac cycle simple nutrients into cells the circulatory system biology

  1. Purkinje fibre

  2. SA node and AVN

  3. Bundle of his and SAN

  4. All of the above

Show answer
Correct Option: B
Explanation:
  • Sino-atrial node (SA node) is located the right upper corner of the right atrium and AVN(AV node) is located in the lower-left corner of the right atrium close to the atrioventricular septum.
  • The SAN can generate the maximum number of action potentials, i.e., $70-75 min^{–1}$, and is responsible for initiating and maintaining the rhythmic contractile activity of the heart. Therefore, it is called the pacemaker. From the SA node, the action potential is conducted from the atria to ventricles by AVN.
  • Hence the action potential is conducted from the atria to ventricles via SA node and AVN.
  • So, the correct answer is 'SA node and AVN'.

Sinoatrial node (SAN) is located at

cardiac cycle simple nutrients into cells the circulatory system biology

  1. Right upper corner of right atrium

  2. Right Lower lower corner of right atrium

  3. Right upper corner of left atrium

  4. Left upper corner of right atrium

Show answer
Correct Option: A
Explanation:

The sinoatrial node is present at the right upper corner of the right atrium. The node is present below the Vena Cava. It initiates the autonomous contraction of the heart muscles.

So, the correct option is 'Right upper corner of right atrium'.

Give these structure of the conduction system of the heart :
1. It is Atrioventricular bundle
2. AV node
3. Bundle branches
4. Purkinje fibres 
 5. SA node
Choose the arrangement that lists the structures in an order of an action potential passes through them.
cardiac cycle simple nutrients into cells the circulatory system biology

  1. $2,5,3,1,4$

  2. $5,2,1,3,4$

  3. $2,5,1,3,4$

  4. $5,2,4,1,3$

Show answer
Correct Option: B
Explanation:

The correct series is 

5.SA node
2.AV node
1.It is atrioventricular bundle
3.Bundle branches
4. Purkinje fibers
So, the correct answer is '5,2,1,3,4'

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

Show answer
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

Show answer
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'