試題詳解

39. Which of the following statements about human respiration is true?
(A) Most of the carbon dioxide in the blood is bound to hemoglobin.
(B) Increased pH level decreases affinity of hemoglobin for O2 and improves the unloading reaction.
(C) At normal systemic venous PO2, about 25% of the hemoglobin is in the form of oxyhemoglobin.
(D) Surfactants can increase the surface tension of the lungs.
(E) During an unforced exhalation, alveolar pressure is greater than atmospheric pressure.