22. The Respiratory System

Doris has an obstruction of her right primary bronchus. As a result, how would the oxygen–hemoglobin saturation curve for her right lung compare with that for her left?

Gas exchange at the blood air barrier is efficient because

(a) The differences in partial pressure are substantial

(b) The gases are lipid soluble

(c) The total surface area is large

(d) Of all of these

What is the approximate partial pressure of oxygen in the blood as it enters and leaves the capillaries of the alveoli?

Choose which of the following statements is correct.

What is the significance of

(c) Henry's law to the process of respiration?

For internal respiration, which of the following must be true:

I. The total amount of CO₂ exchanged equals the amount of O₂ exchanged.

II. Carbon dioxide will move down its pressure gradient to enter the blood.

III. The partial pressure of O₂ in the tissue before gas exchange is ≥ 40 mm Hg.

Which gradient most directly determines the direction that oxygen and carbon dioxide molecules will move between the air in the alveoli and the blood:

When determining the directions that molecules will move in external and internal respiration:

Which of the following determines the direction of gas movement?

a. Solubility in water

b. Partial pressure gradient

c. Temperature

d. Molecular weight and size of the gas molecule

What three integrated steps are involved in external respiration?