Which of the following is NOT a characteristic of the respiratory surface of the alveoli?
a) Thin-walled
b) Dry
c) In contact with an environmental source of oxygen
d) In contact with the transport system that carries dissolved materials to and from the cells of the organism
Why would it be dry?
b) Dry
To determine which of the characteristics is NOT a characteristic of the respiratory surface of the alveoli, let's analyze each option:
a) Thin-walled: The respiratory surface of the alveoli is indeed thin-walled to allow for efficient gas exchange. Oxygen and carbon dioxide can diffuse through these thin walls, facilitating the exchange between the alveoli and the bloodstream.
b) Dry: The respiratory surface of the alveoli is moist to aid in the exchange of gases. The moisture helps to dissolve gases, making it easier for them to pass through the alveolar walls.
c) In contact with an environmental source of oxygen: The respiratory surface of the alveoli is in contact with the inhaled air, which contains oxygen. When air is inhaled, oxygen passes through the respiratory system and reaches the alveoli, where it can diffuse into the bloodstream.
d) In contact with the transport system that carries dissolved materials to and from the cells of the organism: This is the characteristic that is NOT true for the respiratory surface of the alveoli. The alveoli are not directly in contact with the transport system that carries dissolved materials to and from the cells of the organism. Instead, oxygen diffuses into the bloodstream from the alveoli, and from there, it is transported by the circulatory system to the cells.
Therefore, the correct answer is d) In contact with the transport system that carries dissolved materials to and from the cells of the organism.