21) Exchange of both oxygen and carbon dioxide through the respiratory membrane occurs by:

A) osmosis

B) simple diffusion

C) facilitated diffusion

D) active transport

E) endocytosis

22) The lipid molecule critical to lung function that coats the gas-exposed alveolar surfaces is called:

A) surfactant

B) interferon

C) kinin

D) renin

E) lecithin

23) Air moving in and out of the lungs is called:

A) internal respiration

B) inspiration

C) external respiration

D) expiration

E) pulmonary ventilation

24) Which one of the following is NOT true of inspiration:

A) contraction of the diaphragm muscle helps increase the size of the thoracic cavity

B) relaxation of the external intercostal muscles helps increase the size of the thoracic cavity

C) increased intrapulmonary volume causes inhaled gases to spread out

D) the decreased gas pressure produces a partial vacuum that forcibly sucks air in

E) air continues to move into the lungs until intrapulmonary pressure equals atmospheric pressure

25) The gas exchange that occurs between blood and tissue cells at systemic capillaries is called:

A) pulmonary ventilation

B) expiration

C) internal respiration

D) external respiration

E) respiratory gas transport

26) Expiration (exhalation) occurs when:

A) diaphragm and intercostal muscles contract

B) air moves into the lungs

C) intrapulmonary volume increases

D) diaphragm and intercostal muscles relax

E) intrapulmonary pressure decreases

27) Which nonrespiratory air movement clears the upper respiratory passageways:

A) coughing

B) yawning

C) laughing

D) hiccupping

E) sneezing

28) The presence of air in the intrapleural space is known as:

A) atelectasis

B) asthma

C) hypoxia

D) pleurisy

E) pneumothorax

29) The respiratory movement representing the total amount of exchangeable air is the:

A) tidal volume

B) inspiratory reserve volume

C) expiratory reserve volume

D) vital capacity

E) dead space volume

30) The amount of air that can be forcibly exhaled after a tidal expiration is about:

A) 500 mL

B) 1200 mL

C) 2100 mL

D) 4800 mL

E) 6000 mL