The lungs are always inflated and do not normally collapse even during expiration because of
1. surfactant.
2. pleural pressure.
3. elastic recoil.
4. both 1 and 2.

The pulmonary function of a person reveals the following values:
a. tidal volume = 500 mL
b. residual volume = 1000 mL
c. inspiratory reserve volume = 2500 mL
d. expiratory reserve volume = 1000 mL
His vital capacity is

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?

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: