Pacemaker of Heart

Q.

Sino-atrial node is called the pacemaker of our heart. Why?

Q.

Why do we call our heart myogenic?

Q.

What is the most important brain or heart?

Q. The correct route through which pulse-making impulse travels in the heart is:

1. SA node → Purkinje fibres → bundle of His → AV node → heart muscles
2. AV node → bundle of His → SA node →Purkinje fibres → heart muscles
3. AV node → SA node → Purkinje fibres →bundle of His → heart muscles
4. SA node → AV node → bundle of His →Purkinje fibres → heart muscles

Q. Which of the following statements define a myogenic heart?

1. A heart with 4 chambers is called a myogenic heart.
2. A heart in which the blood circulates twice is called a myogenic heart.
3. A heart that does not require neural input to beat is called a myogenic heart.
4. A heart that requires neural input to beat is called a myogenic heart.

Q. Which of the following is called the pacemaker of the heart?

1. Sinoatrial node
2. Atrioventricular node
3. Purkinje fibres
4. Bundle of His

Q. Artificial pacemaker is used to replace

1. AVN
2. Purkinje fibres
3. SAN
4. Bundle of His

Q. The first heart sound (lub) is associated with:

1. Closure of bicuspid and aortic valves.
2. Opening of the tricuspid and bicuspid valves.
3. Closure of the tricuspid and bicuspid valves.
4. Opening of pulmonary and tricuspid valves

Q. Choose the incorrect statement with respect to breathing and respiration in humans:

1. The volume of the thoracic chamber increases due to the contraction of diaphragm and external inter-costal muscles.
2. $O_2$ and ${\mathrm{CO}}_2$ transports in the blood majorly through RBCs and as bicarbonate, respectively.
3. High ${\mathrm{pO}}_2$, low ${\mathrm{pCO}}_2$, lesser $H^{+}$ concentration and lower temperature promotes formation of oxyhaemoglobin.
4. ${\mathrm{CO}}_2$ and $H^{+}$ concentration is insignificant and oxygen plays a huge role in the regulation of respiratory rhythm.

Q. Choose the correct statement about the sino-atrial node.

1. Beating of these fibres result in heart sounds
2. They are the neurons originating from the brain and ending at the ventricles
3. Generates action potential without an external stimulus
4. Regulates the inflow of blood into aorta

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

1. AVN
2. SAN
3. Purkinje’s fibres
4. Bundle of His

Q.

Answer the following

(i) name the major site where RBCs are formed.

(ii) Which part of heart is responsible for initating and maintaining its rhythmic activity?

(iii) what is specific in the heart of crocodiles among reptilians?

Q.

In the diagrammatic presentation of heart given below, mark and label. SAN, AVN, AV bundles, bundle of his and Prukinje fibres.

Q.

How does cardiac output affect blood pressure?

Q.

Explain Intrinsic Regulation.

Q. Sinoatrial node is present in

1. right auricle
2. right ventricle
3. left auricle
4. interventricular septum

Q.

When are the sounds "LUB" and "DUB" produced?

Q. Which of the following statements define a myogenic heart?

1. A heart with 4 chambers is called a myogenic heart.
2. A heart in which the blood circulates twice is called a myogenic heart.
3. A heart that does not require neural input to beat is called a myogenic heart.
4. A heart that requires neural input to beat is called a myogenic heart.

Q. What function does the artificial pacemaker perform?

1. Decreases the rate of heart beat
2. Increases the rate of heart beat
3. Maintains the normal rate of heart beat
4. None of the above

Q.

The heart’s natural pacemaker is termed as the:

1. sinoatrial node

2. atrioventricular node

3. bundle of His

4. left and right bundle branches

Q. Sinoatrial node is present in

1. right auricle
2. right ventricle
3. left auricle
4. interventricular septum

Q. Assertion :Mammalian heart is called myogenic heart. Reason: Heart-beat is regulated by a specialized muscle bundle (pacemaker) in mammals.

1. Both (A) and (R) are true and (R) explains (A).
2. Both (A) and (R) are true but (R) doesnt explain (A)
3. (A) is true but (R) is false.
4. (A) is false but (R) is true.

Q.

Is BNP always elevated in heart failure?

Q. Which of the following is called the pacemaker of the heart?

1. Sinoatrial node
2. Atrioventricular node
3. Purkinje fibres
4. Bundle of His

Q. Heart beat is controlled by which cranial nerve?

1. X
2. IX
3. V
4. III

Q. Which of the following is called the pacemaker of the heart?

1. Sinoatrial node
2. Atrioventricular node
3. Purkinje fibres
4. Bundle of His

Q. State whether the following statements are true or false.
Human heart is neurogenic because the heart beat originates in the nodal tissues.

1. True
2. False

Q. Who gave the term 'protoplasm'?

1. Johannes Purkinje
2. Antonie Philips van Leeuwenhoek
3. Matthias Jakob Schleiden
4. Robert Hooke

Q.

The cardiac impulse is initiated and conducted further upto ventricle.The correct sequence of conduction of impulse is:

1. S A Node, A V Node, Purkinje fiber, A V Bundle

2. S A Node, Purkinje fiber, A V Node, A V Bundle

3. S A Node, A V Node, A V Bundle, Purkinje fiber

4. S A Node, Purkinje fiber, A V Bundle, A V Node

Q. Artificial pacemaker is used to replace

1. AVN
2. Purkinje fibres
3. SAN
4. Bundle of His