PATHOLOGY MCQ
RESPIRATORY SYSTEM
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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the volume of the thoracic cavity increases and the pressure decreases, causing air to rush into the lungs.
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the volume of the thoracic cavity decreases and the pressure increases causing air to rush out of the lungs.
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Either A or B
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None of the above
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Detailed explanation-1: -When the lungs inhale, the diaphragm contracts and pulls downward. At the same time, the muscles between the ribs contract and pull upward. This increases the size of the thoracic cavity and decreases the pressure inside. As a result, air rushes in and fills the lungs.
Detailed explanation-2: -During inspiration, the diaphragm contracts and the thoracic cavity increases in volume. This decreases the intraalveolar pressure so that air flows into the lungs. Inspiration draws air into the lungs.
Detailed explanation-3: -The correct answer: When the diaphragm contracts, the volume of the thorax increases, thoracic pressure c) decreases, and air rushes into the lungs. The diaphragm is a muscular structure that is present just below the lungs which are the lowermost region of the thorax.
Detailed explanation-4: -Upon inhalation, the diaphragm contracts and flattens and the chest cavity enlarges. This contraction creates a vacuum, which pulls air into the lungs. Upon exhalation, the diaphragm relaxes and returns to its domelike shape, and air is forced out of the lungs.