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QUESTION
Q142) If the thoracic wall but not lungs is punctured ....

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If the chest wall, is punctured, blood, air or both can enter the pleural space. Air/blood rushes into the space in order to equalise the pressure with that of the atmosphere. As a result, the fluid is disrupted and the two membranes no longer adhere to each other. When the rib cage moves out, it no longer pulls the lungs with it. Thus the lungs cannot expand, the pressure in the lungs never drops and no air is pulled into the bronchi. Respiration is not possible. The affected lung, which has a great deal of elastic tissue, shrivels in what is referred to as a collapsed lung. Thus the man dies as the lungs get collapsed
Answer : (b)