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Which is the first Heart sound ?...

Which is the first Heart sound ?

A

Lub associated with the closure of Semi-lunar valves

B

Lub associated with the closure of tricuspid and bicuspid valves

C

Dub associated with the closure of tricuspid and bicuspid valves

D

Dub associated with the closure of Semilunar valves

Text Solution

AI Generated Solution

The correct Answer is:
**Step-by-Step Solution:** 1. **Understanding Heart Sounds**: The heart produces two primary sounds during each cardiac cycle, commonly referred to as "lub" and "dub." These sounds are associated with the closure of heart valves. 2. **Identifying the First Heart Sound**: The first heart sound is referred to as "lub." It is produced by the closure of the mitral and tricuspid valves at the beginning of ventricular systole (the phase of the heartbeat when the ventricles contract). 3. **Characteristics of the First Heart Sound**: - The first heart sound (lub) is low-pitched and slightly prolonged. - It lasts approximately 0.15 seconds. - The frequency of the first heart sound ranges from 25 to 45 Hertz. 4. **Contrasting with the Second Heart Sound**: The second heart sound, known as "dub," occurs shortly after the first sound and is associated with the closure of the aortic and pulmonary valves at the end of ventricular systole. It is shorter and has a higher pitch, lasting about 0.12 seconds with a frequency of around 50 Hertz. 5. **Conclusion**: Therefore, the first heart sound (lub) is specifically associated with the closure of the mitral and tricuspid valves. **Final Answer**: The first heart sound is "lub," associated with the closure of the mitral and tricuspid valves. ---
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The first heart sound is

Which of the following events takes place in cardiac cycle after the end of first heart sound and before the onset of second heart sound?

Knowledge Check

  • The first heart sound is produced when

    A
    diastole begins
    B
    semilunar valves close quickly
    C
    interventricular pressure increases
    D
    bicuspid and tricuspid valves close quickly

    • Similar Questions

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    Which of the following statement is CORRECT ? I. Heart, the mesodermally derived organ, is situated in the thoracic cavity, in between the two lungs , slightly tilted to the left. II. During joint diastole , tricuspid and bicuspid valves are open and the semilunar values are closed. III. The first heart sound (lub) is associated with the closure of the tricuspid and biscuspid valves whereas the second heart sound (dub) is associated with the closure of the semilunar valves . IV. Neural signals through the sympathetic nerves can increases the rate of hearbeat, the strength of ventricular contraction and thereby the cardiac output.

    Read the following four statements (1-4) (1 ) The second heart sound is DUB, which is associated with the closure of bicuspid and tricuspid valves . (2) The duration between consecutive second and first heart sound is 0.5 second in a cardiac cycle . (3) The heartbeat of a human increase when the adrenaline hormone in injected into it. (4) The atrial systole in a cardiac cycle increase the flow of blood into the respective ventricle by about 70% . How many of the above statements are incorrect ?

    choose the correct option w.r.t. first heart sound.

    The "lubb" sound (first heart sound) is caused by

    The first heart sound lubb' is associated with

    The first heart sound results from the closure of semilunar valves.

    Read the following statement and choose the correct option. A. The first heart sound (lub) is associated with the closure of both semilunar valves. The duration between the adjacent second heart sound and first heart sound is 0.3 seconds C. The cardiac output is the stroke volume multiplied by the number of heartbeats per minute.

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