MEDICINE
RESPIRATORY MEDICINE
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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It leaves the alveoli and is exhaled from the lungs
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It leaves the bloodstream and enters the alveoli
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It leaves the cells and enters the bloodstream
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It leaves the alveoli and enters the bloodstream
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Detailed explanation-1: -Once the venous blood returns to the lungs, the carbon dioxide diffuses out of the bloodstream, through the capillaries, and into the alveoli from where it is expelled, during which time oxygen simultaneously binds with hemoglobin to be carried back to the tissues.
Detailed explanation-2: -During gas exchange oxygen moves from the lungs to the bloodstream. At the same time carbon dioxide passes from the blood to the lungs. This happens in the lungs between the alveoli and a network of tiny blood vessels called capillaries, which are located in the walls of the alveoli.
Detailed explanation-3: -Carbon dioxide is transported in the blood from the tissue to the lungs in three ways:1 (i) dissolved in solution; (ii) buffered with water as carbonic acid; (iii) bound to proteins, particularly haemoglobin. Approximately 75% of carbon dioxide is transport in the red blood cell and 25% in the plasma.