22. The Respiratory System

Which muscle is used for inspiration during both eupnea and forced breathing?

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.

Match each term with the correct definition. 

Airway resistance     

Surface tension     

Surfactant     

Pulmonary compliance     

V/Q ratio

a. A detergent-like chemical secreted by bronchial smooth muscle that reduces surface tension

b. The matching of ventilation to perfusion

c. Largely determined by the diameter of the airways

d. Caused by the formation of hydrogen bonds between water molecules

e. Determined by the surface tension of the alveoli, the elastic tissue of the lungs, and the condition of the chest wall

If you swallow a large bite of food without properly chewing it first, you will feel discomfort during ventilation. Explain this, considering the arrangement of the trachea and the esophagus.

At the end of inspiration, the intrapulmonary pressure is equal to ____________.

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?

Why does air rush into the lungs during an inhale or inspiration?

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

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

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

Which of the following represents intrapleural pressure?

Which muscle is likely to be contracting while blowing up a balloon?