22. The Respiratory System

Gas A and Gas B are both mixtures separated by a permeable membrane. Gas A contains 40% nitrogen at a partial pressure of 300 mm Hg. Gas B contains 80% nitrogen at partial pressure of 200 mm Hg. Given this information, in which direction do you expect to see a net movement of nitrogen and why?

Henry's law states that the degree to which a gas dissolves in a liquid is determined by its:

a. partial pressure.

b. solubility.

c. surface tension.

d. Both a and b are correct.

e. All of the above are correct.

You and a friend are having a contest to see who can hold his or her breath the longest. Your friend hyperventilates before holding his breath, and subsequently wins the contest. Why did hyperventilation give him an advantage?

Fill in the blanks: When the alveolar Po₂ decreases, the pulmonary arterioles_____. When the arteriolar Pco₂ increases, the bronchioles_______.

How is Henry’s law related to the amount of gas that can be exchanged in the alveoli?

Gas A is 40% oxygen and 10% CO₂. It has a total pressure of 500 mm Hg. Gas A is in contact with a with a liquid containing oxygen at a partial pressure of 100 mmHg and CO₂ at a partial pressure of 25 mm Hg. In which direction will O₂ and CO₂ diffuse in this situation?

Air in the alveoli is approximately 5.2% CO₂. Given that information along with the total air pressure in the alveoli, which law would allow you to calculate the partial pressure of CO₂?