BLOOD CARDIOVASCULAR SYSTEM LYMPHOID ORGANS
CARDIOVASCULAR SYSTEM
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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the atria are receiving and upper chambers of the heart
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the ventricles are the pumping and lower chambers of the heart
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the tricuspid and bicuspid valves prevent the backflow of blood into the atria
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the lub sound of the heart in the lub-dub is caused by the closing of the semilunar valves
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Detailed explanation-1: -The familiar ‘lub-dub’ sound of the heartbeat is caused by the rhythmic closing of the heart valves as blood is pumped in and out of the chambers. A heart murmur is a sound caused by blood flow within the heart. Instead of ‘lub-dub’, the heartbeat may have an added sound like a hum, a whoosh or a rasp.
Detailed explanation-2: -The second heart sound, S2, is the sound of the closing of the semilunar valves during ventricular diastole and is described as a “dub” (Fig. 1.21).
Detailed explanation-3: -Heart sounds are caused by opening and closing or hert valves. normal sounds are called ‘murmurs’. Heart sounds are produced by the closing and opening of the AV valves and semilunar valves.
Detailed explanation-4: -The first heart sound, “lub, ‘’ is caused by the closure of the right and left atrioventricular valves. The second heart sound, “dub, ‘’ is caused by the closure of the aortic and pulmonary semilunar valves.