22. The Respiratory System

Cary hyperventilates for several minutes before diving into a swimming pool. After he enters and begins swimming underwater, he blacks out and almost drowns. What caused this to happen?

Mark the following statements as true or false. If a statement is false, correct it to make a true statement.

The epithelium of the oropharynx changes from stratified columnar epithelium to simple squamous epithelium to enable it to resist abrasion from food.

The detergent-like substance that keeps the alveoli from collapsing between breaths because it reduces the surface tension of the water film in the alveoli is called:

a. Lecithin

b. Bile

c. Surfactant

d. Reluctant

What is the significance of

(a) Boyle's law, to the process of respiration?

When the volume of air in the lungs is the greatest:

Predict what would happen to the tidal volume and inspiratory reserve volume if the phrenic nerves were severed. Which muscles would contract to try to compensate for this?

Differentiate clearly between minute ventilation and alveolar ventilation rate

Which provides a more accurate measure of ventilatory efficiency, and why?

When the diaphragm and external intercostal muscles contract,

(a) Exhalation occurs.

(b) Intrapulmonary pressure increases.

(c) Intrapleural pressure decreases.

(d) The volume of the lungs decreases.

(e) The size of the thoracic cavity increases.

Explain what would happen to the pressure inside a cylinder if you decreased its volume, according to Boyle's law.

Which of the following does not affect the efficiency of pulmonary gas exchange?

a. The surface area of the respiratory membrane

b. The degree of match of ventilation to perfusion

c. The percent saturation of hemoglobin

d. The thickness of the respiratory membrane

Which of the following statements about pulmonary ventilation is false?

a. Normal expiration requires the use of the expiratory muscles to decrease lung volume.

b. The inspiratory muscles increase lung volume, which decreases intrapulmonary pressure.

c. For inspiration to occur, intrapulmonary pressure must decrease below atmospheric pressure.

d. The intrapleural pressure is less than the intrapulmonary pressure; this prevents the lungs from collapsing during expiration.

As a result of a stroke, Mrs. Minnick's swallowing is uncoordinated. What detrimental effect might this have on her ability to breathe?