Which one of the following acts as functional unit of lungs in man?
Correct answer: A. Air sac
- A. Air sac
- B. Trachea
- C. Larynx
- D. Bronchioles
Explanation
Option [a] Air sacs, and alveoli are present at the end of bronchioles in lungs where lungs and blood exchange oxygen and carbon dioxide during inhalation and exhalationOption[b] The Larynx(voice box) contains vocal cords not the part of the lungsOption[c] Trachea that connects the larynx to the lungs. Acts as a passage of air into the lungs.( not the part of the lungs)Option[d] Bronchioles are the smaller branches of the bronchi that enter each lung. Bronchioles give rise to alveoli (air sacs)
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About Gaseous Exchange in Lungs
Gaseous exchange in the lungs occurs across the thin, moist alveolar and capillary surfaces, where oxygen and carbon dioxide diffuse down partial pressure gradients. The topic covers alveolar adaptations, ventilation, the role of haemoglobin in oxygen transport, carbon dioxide carriage, and the difference between external gas exchange and cellular respiration.
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