Lub-dup sound is produced due to action of

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Q: 66 (NDA-I/2015)
‘Lub-dup’ sound is produced due to action of

question_subject: 

Science

question_exam: 

NDA-I

stats: 

0,17,12,6,2,17,4

keywords: 

{'lungs': [3, 0, 0, 1], 'lub': [0, 0, 0, 1], 'oesophagus': [0, 0, 1, 3], 'sound': [4, 3, 10, 15], 'large intestine': [5, 0, 3, 3], 'dup': [0, 0, 0, 1], 'heart': [1, 0, 0, 0]}

The correct answer is option 3, Heart.

The `lub-dup` sound that we hear is a result of the action of the heart. The heart is a muscular organ located in the chest, slightly to the left, and it is responsible for pumping blood throughout the body. The `lub-dup` sound corresponds to the closing of the heart valves.

When the heart beats, blood is pumped from the atria (upper chambers) into the ventricles (lower chambers) through the open valves. The first sound, `lub`, is produced when the atrioventricular (AV) valves close to prevent the backflow of blood from the ventricles into the atria. The second sound, `dup`, is produced when the semilunar valves close to prevent the backflow of blood from the arteries into the ventricles.

Hence, the `lub-dup` sound is a crucial auditory indication of a normally functioning heart and the correct answer is option 3, Heart.