22. The Respiratory System

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.

What factor is most important in keeping the lungs from collapsing?

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?

Individuals with COPD (chronic obstructive pulmonary disorder) have degraded elastin protein, causing their lungs to have less recoil. How would this affect intrapleural pressure and why?

True or false: if false choose the answer that best corrects the statement.

In healthy lungs, the intrapulmonary pressure is always lower than the intrapleural pressure.

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?

Pleural effusion is a condition where fluid accumulates in the pleural cavity. Which pressure or pressures would you expect to be most directly impacted by this fluid accumulation?

Define hyperventilation

If you hyperventilate, do you retain or expel more carbon dioxide?

What effect does hyperventilation have on blood pH?

What happens to the metabolic rate of skeletal muscle tissue during exercise? What waste products are produced from metabolic reactions? How and why does this affect your rate of ventilation during exercise?