The atmospheric air pressure at sea level is 760 mm Hg and 20% of it is composed of oxygen. What would be the partial pressure of oxygen in atmospheric air?

1.	152 mm Hg	2.	40 mm Hg
3.	104 mm Hg	4.	159.6 mm Hg

Exchange of gases occurs across the respiratory membrane. Which of the following would increase the rate of diffusion of a gas across the respiratory membrane?

Hemoglobin in blood can more readily combine with carbon dioxide when blood passes through the tissues. This is due to:
1. Bohr effect.
2. Haldane effect
3. chloride shift
4. Hering-Breuer Reflex

The chloride shift is also known as Hamburger phenomenon and it
1. occurs primarily in pulmonary capillaries.
2. occurs when Cl- replace HCO3- within red blood cells.
3. decreases the formation of bicarbonate ions.
4. decreases the number of hydrogen ions.

The middle ear cavity is connected to the nasopharynx by:

During swallowing, the food is prevented from entering into the nasal cavity by:
1. hard palate.
2. larynx.
3. fauces.
4. uvula.

What is the correct chronological sequence of the following structures as air passes through them in inhalation?
a. alveolar duct
b. alveolus
c. respiratory bronchiole
d. terminal bronchiole
1. a, b, c, d
2. b, c, d, a
3. c, d, a, b
4. d, c, a, b

The most negative pressure at the end of normal inspiration would be:

In inspiration during pulmonary ventilation the correct order of the given events is:
a. air flows into the lungs
b. alveolar volume increases
c. thoracic volume increases
d. pleural pressure decreases
e. alveolar pressure decreases

The volume of air that is available for gas exchange each minute is the
1. minute ventilation
2. anatomical dead air space
3. physiological dead air space
4. alveolar ventilation