Conduction in Heart

Q.

Why ventricles have thicker walls?

Q.

When a frogs heart is removed from its body, it continues to beat for some time.

Choose the most appropriate option from the following statements.

1. Frog is a poikilotherm
2. A frog does not have any coronary circulation
3. Heart is ‘myogenic’ in nature
4. Heart is autoexcitable

1. Only (c)

2. Only (d)

3. (a) & (b)

4. (c) & (d)

Q.

Depolarisation of atria is represented by:

1. T-wave

2. P-wave

3. QRS complex

4. Q-wave

Q.

Ventricles are thick walled as compared to auricles because

1. It has to receive blood from auricles

2. It is present in posterior side

3. It has to pump the blood with more force

4. It has to pump blood to auricles

Q. What is a cardiac cycle? Note down the steps involved in it.

Q.

The phase of cardiac cycle in which the auricles contract

Q.

The pacemaker of heart is

1. AV node

2. SA node

3. SV node

4. Tricuspid valve

Q.

Rate of heartbeat is determined by

1. SA node

2. AV node

3. Purkinje fibres

4. Papillary muscles

Q. ‘Heart of heart’ is called:

[Review question: Pg. No: 214]

Q.

The given diagram represents a section of the human heart. Answer the questions that follows.

Draw neat labelled diagrams of a cross sections of an artery and a vein.

Q.

define pericardium.

What are properties of cardiac muscles of heart.

why is left ventricle thickest chamber of heart.

what is the effect of atrial systole on the flow of blood.

Name 2 types of circulation found in man.

ANSWER IT) give thw composition of lymph.

main function of lymph.

Q. coronary sinus recives blood from cardiac muscles but what supply the oxygenated blood to the cadiac muscle ?

Q.

Find out the wrong statement:

1. Tricuspid valve is located between right atrium and right ventricle

2. SA node is called the pacemaker of the heart

3. By counting the number of QRS complexes that occur in a given time period, one can determine the heart beat rate of an individual

4. The P wave represents the depolarization of the atria while QRS complex represents the repolarization of the ventricles

Q. QRS complex in an ECG is not related to
A. Ventricular contraction
B. A measure of determining the heartbeat
C. Stroke volume of the cardiac cycle
D. Ventricular depolarization

Q.

If you cut your skin, it can e, but after a stroke or brain injury, you can't replace neurones. Why is it so? What might be the evolutionary significance of this?

Q.

Where are isolated premature atrial contractions common?

Q. What happens when the pacemaker is non functional?

1. Only ventricles contract rhythmically.
2. Cardiac muscles will contract in a coordinated manner.
3. Only the auricles will contract rhythmically
4. The cardiac muscles do not contract in a coordinated manner rhythmically.

Q.

Assertion[A]: Atria and ventricles do not contract at the same time.

Reason[R]: This time delay allows proper filling of all the 4 chambers of the heart and results in an efficient pumping of blood.

1. A is true and R is false.

2. R is true and A is false.

3. Both A and R are true and R is correct explanation of A.

4. Both A and r are true but R is not correct explanation for A.

Q.

Which of the following statement is/are correct?

A marathon runner is likely to show
1. Reduced heart rate
2. Enlarged heart
3. Larger stroke volume
4. Decreased arterial blood pressure

1. All of the above

2. 1, 2 and 3

3. 1 and 2

4. 1 alone

Q. Frog's heart, when taken out of the body, continues to beat for some time.
Select the best option from the following statements.
(a) Frog is a poikilotherm
(b) Frog does not have any coronary circulation
(c) Heart is "myogenic" in nature
(d) Heart is auto-excitable

1. Only (d)
2. (a) and (b)
3. (c) and (d)
4. Only (c)

Q.

Identify the labelled parts of heart’s conduction system as depicted in the image.

1. (i)Purkinjefibres, (ii)Bundle of His, (iii) SA node, (iv) AV node

2. (i)SA node, (ii) AV node, (iii) Bundle of His, (iv) Purkinje fibres

3. (i)Bundle of His, (ii) Purkinjefibres, (iii) AV node, (iv) SA node

4. (i)SA node, (ii) Purkinjefibres, (iii) AV node, (iv) Bundle of His

Q.

ECG is used for recording electric waves found in the ___.

1. Lungs

2. Heart

3. Brain

4. Spinal cord

Q.

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

1. SA node; AV node; AV bundle; Purkinje fibre​
2. SA node; Purkinje fibre; AV node; AV bundle​
3. SA node; Purkinje fibre; AV bundle; AV node​
4. SA node; AV node; Purkinje fibre; AV bundle​

Q.
In the given diagram, which of the following contract together?

1. A and B
2. B and D
3. C and D
4. A and C

Q.

Which of the following is not true about the heart’s conduction system?

1. The SA node generates action potentials higher than all the other parts of the conducting system.

2. The SA node generates specifically 70 action potentials per minute.

3. If all the other portions of the conducting system other than the SA node, produce action potentials at a much slower rate, it would maintain our heart rate.

4. Other muscles receive impulses through the neurons from the brain, but heart produces its own potential

Q. Assertion: SA node induces excitatory impulses in the heart.
Reason: S.A. node is self-excitatory.

1. Both assertion and reason are false.
2. Both assertion and reason, are true and the reason is the correct explanation of assertion.
3. Both assertion and reason, are true but the reason is not the correct explanation of the assertion.
4. The assertion is true but the reason is false

Q. More than One Answer Type
एक से अधिक उत्तर प्रकार के प्रश्न

Which of the following correctly describes the effect of sympathetic division of ANS on the cardiac activity?

(a) Increases cardiac output
(b) Increases ventricular force of contraction
(c) Decreases speed of signal transmission
(d) Functions during emergency conditions that increases heart rate

Choose the correct option(s):

निम्नलिखित में से कौनसा हृदय क्रिया पर ANS के अनुकंपी प्रभाग के प्रभाव का वर्णन सही ढंग से करता है?

(a) हृदय निकास बढ़ जाता है
(b) संकुचन की निलयी शक्ति बढ़ जाती है
(c) संकेत संप्रेषण की गति कम हो जाती है
(d) आपातकाल परिस्थितियों के दौरान कार्य करता है जिससे हृदय दर बढ़ जाती है

सही विकल्प/विकल्पों का चयन कीजिए:

1. a, b
2. a, b, c
3. b, d
4. b, c

Q. Assertion: SA node induces excitatory impulses in the heart.
Reason: S.A. node is self-excitatory.

1. Both assertion and reason, are true and the reason is the correct explanation of assertion.
2. The assertion is true but the reason is false
3. Both assertion and reason, are true but the reason is not the correct explanation of the assertion.
4. Both assertion and reason are false.

Q.

The heart’s natural pacemaker is termed as the:

1. atrioventricular node

2. bundle of His

3. left and right bundle branches

4. sinoatrial node

Q. Synapse is a close proximity of
(a) two veins
(b) two arteries
(c) two muscles
(d) two nerves