Tag: heart, blood vessels and cardiac cycle

Questions Related to heart, blood vessels and cardiac cycle

Which of the following statements is false?

biology transportation in plants and circulation in animals heart beat cardiac cycle heart, blood vessels and cardiac cycle

  1. $Mg^{2+}$ ions form a complex with ATP

  2. $Ca^{2+}$ ions are important in blood clotting

  3. $Ca^{2+}$ ions are not important in maintaining the regular beating of the heart

  4. $Mg^{2+}$ ions are important in the green parts of plants.

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Correct Option: C
Explanation:

Calcium is important for heart because the movement of calcium ions help the heart muscles to contract. This occurs because: calmodulin, a protein binds to the sodium channel, helps keep it open. Calcium ions regulate the connection between the protein and the channel by causing the protein to hook up to the channel. This in turn, keeps it open and allows sodium ions to pass through. In the absence of Ca$^2$$^+$ the heart beat will be irregular. 

So the correct answer is ' Ca2+ ions are not important in maintaining the regular beating of the heart'.

The first heart sound is

biology transportation in plants and circulation in animals heart beat cardiac cycle heart, blood vessels and cardiac cycle

  1. DUP

  2. LUBB

  3. LUPP

  4. BUD

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Correct Option: B
Explanation:

The first heart sound 'lubb' is made by the closing of the mitral valve and tricuspid valve (atrioventricular valves). The second heart sound is 'dub' and is caused by the closure of the aortic valve and the pulmonary valve. 

So, the correct option is 'LUBB'.

In human beings heart beat is initiated by

biology transportation in plants and circulation in animals heart beat cardiac cycle heart, blood vessels and cardiac cycle

  1. Purkinje fibres

  2. AV node

  3. SA node

  4. Bundles

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Correct Option: C
Explanation:

Sinoatrial node is a cluster of cells present in the right atria just below the opening of  Vena cava. It autonomously generates electrical impulses that initiate the muscle contraction in the atria.

It is called the natural pacemaker of the heart.
So, the correct answer is 'SA node'.

First heart sound is called?

biology transportation in plants and circulation in animals heart beat cardiac cycle heart, blood vessels and cardiac cycle

  1. Lubb

  2. Dub

  3. Murmur

  4. None of these

Show answer
Correct Option: A
Explanation:

  • The heart produces a characteristic sound at the beginning g of ventricular systole or contraction. 
  • These sounds are a result of the closure of the atrioventricular valves, the mitral valve and the tricuspid valve. 
  • The sounds produced are “lubb-dub”, lubb being the first of the two. 
  • So, the correct answer is 'Lubb'.

An artifical pacemaker is implanted sub-cutaneously and connected to heart in patients.

biology transportation in plants and circulation in animals heart beat cardiac cycle heart, blood vessels and cardiac cycle

  1. having high B.P

  2. having irregularity in heartbeat

  3. having blockage in heart

  4. suffering from arteriosclerosis.

Show answer
Correct Option: B
Explanation:

A pacemaker insertion is the implantation of a small electronic device that is usually placed in the chest (just below the collarbone) to help regulate slow electrical problems with the heart. A pacemaker may be recommended to ensure that the heartbeat does not slow to a dangerously low rate.


So, the Correct option is B.

Human heart is myogenic and it is supplied with sympathetic and vagus nerve branches that are acceleratory  and inhibitory in nature respectively.Which one of the following statement is incorrect w.r.t the heart beat?

biology transportation in plants and circulation in animals heart beat cardiac cycle heart, blood vessels and cardiac cycle

  1. In foetal heart the heart rate is $140-130$ beats per minutes

  2. Mental status such as depression and grief decrease heart rate

  3. An excess of $Ca^{++}$ ion decreases heart beat rate

  4. High levels of $Na^+$ and $K^+$ decreases the strength of contraction

Show answer
Correct Option: B
Explanation:

Heartbeat rate is the number of the beating of the heart per minute.

  • It is found that in normal humans, the rate of heartbeat is about 70 - 72 times per minute but in feotus or babies it is found much higher about 140 - 130 times per minute or may even up to 160 per minute. 
  • At the time of mental disorders like depression, grief or sadness body releases stress hormone, these stress hormone tightens the blood vessels, thus increases the heart rate.
  • Calcium ions play a major role in cardiac activity as well in muscle contraction when they are present in high amount then causes a lower heartbeat.
  • Sodium-potassium pumps are the ion channels or proton pumps that regulate the activity of contraction in the heart muscles. Excess of these ions dilates the blood vessels, thus lowers the heart rate and strength of the contraction of the heart muscles.
So, the correct option is 'Mental status such as depression and grief decrease heart rate'.

Time interval between DUP and LUBB is ______ coincide with _____

biology transportation in plants and circulation in animals heart beat cardiac cycle heart, blood vessels and cardiac cycle

  1. $0.3$ sec, ventricular systole

  2. $0.5$ sec, joint diastole and atrial systole

  3. $0.4$ sec, joint diastole

  4. $0.1$ sec, atrial systole

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Correct Option: A

A moderate increase in the concentration of which of the following ions speeds up the heart rate and strengthens the heart beat?

biology transportation in plants and circulation in animals heart beat cardiac cycle heart, blood vessels and cardiac cycle

  1. Na$^+$ ions

  2. Ca$^{2+}$ ions

  3. $K^+$ ions

  4. All of these

Show answer
Correct Option: A

State whether the following statement is true or false. If false rewrite the correct form of the statement by changing the last word.
The sound produced when the atrioventricular valves close in the heart is called dub.

biology transportation in plants and circulation in animals heart beat cardiac cycle heart, blood vessels and cardiac cycle

  1. True

  2. False

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Correct Option: A

What happen on heart beating if the parasym-pathetic nerve going towards heart is cut down?

biology transportation in plants and circulation in animals heart beat cardiac cycle heart, blood vessels and cardiac cycle

  1. Increases

  2. Decreases

  3. Normal

  4. Stopped

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Correct Option: A