482
Chapter 13
mountain sickness (altitude
sickness)
477
obstructive lung disease
455
obstructive sleep apnea
478
pneumothorax
449
pulmonary edema
461
pulmonary embolus
476
pulmonary function test
455
respiratory acidosis
468
respiratory alkalosis
468
respiratory distress syndrome of
the newborn
453
restrictive lung disease
455
shunt
462
sleep apnea
478
ventilation-perfusion
inequality
461
REVIEW QUESTIONS
1. List the functions of the respiratory system.
2. At rest, how many liters of air and blood fl ow through the
lungs per minute?
3. Describe four functions of the conducting portion of the
airways.
4. Which respiration steps occur by diffusion and which by bulk
fl ow?
5. What are normal values for intrapleural pressure, alveolar
pressure, and transpulmonary pressure at the end of an
unforced expiration?
6. Between breaths at the end of an unforced expiration, in what
directions do the lungs and chest wall tend to move? What
prevents them from doing so?
7. State typical values for oxygen consumption, carbon dioxide
production, and cardiac output at rest. How much oxygen (in
milliliters per liter) is present in systemic venous and systemic
arterial blood?
8. Write the equation relating air fl ow into or out of the lungs to
alveolar pressure, atmospheric pressure, and airway resistance.
9. Describe the sequence of events that cause air to move into
the lungs during inspiration and out of the lungs during
expiration. Diagram the changes in intrapleural pressure and
alveolar pressure.
10. What factors determine lung compliance? Which is most
important?
11. How does surfactant increase lung compliance? How does
surfactant stabilize alveoli by preventing small alveoli from
emptying into large alveoli?
12. How is airway resistance infl
uenced by airway radii?
13. List the physical factors that alter airway resistance.
14. Contrast the causes of increased airway resistance in asthma,
emphysema, and chronic bronchitis.
15. What distinguishes lung capacities, as a group, from lung
volumes?
16. State the formula relating minute ventilation, tidal volume, and
respiratory rate. Give representative values for each at rest.
17. State the formula for calculating alveolar ventilation. What is
an average value for alveolar ventilation?
18. The partial pressure of a gas is dependent upon what two factors?
19. State the alveolar partial pressures for oxygen and carbon
dioxide in a normal person at rest.
20. What factors determine alveolar partial pressures?
21. What is the mechanism of gas exchange between alveoli and
pulmonary capillaries? In a normal person at rest, what are the
gas pressures at the end of the pulmonary capillaries, relative to
those in the alveoli?
22. Why does thickening of alveolar membranes impair oxygen
movement but have little effect on carbon dioxide exchange?
23. What is the major result of ventilation-perfusion inequalities
throughout the lungs? Describe homeostatic responses that
minimize mismatching.
24. What generates the diffusion gradients for oxygen and carbon
dioxide in the tissues?
25. In what two forms is oxygen carried in the blood? What are
the normal quantities (in milliliters per liter) for each form in
arterial blood?
26. Describe the structure of hemoglobin.
27. Draw an oxygen-hemoglobin dissociation curve. Put in the
points that represent systemic venous and systemic arterial
blood (ignore the rightward shift of the curve in systemic
venous blood). What is the adaptive importance of the plateau?
Of the steep portion?
28. Would breathing pure oxygen cause a large increase in oxygen
transport by the blood in a normal person? In a person with a
low alveolar
P
O
2
?
29. Describe the effects of increased
P
CO
2
, H
+
concentration, and
temperature on the oxygen-hemoglobin dissociation curve. How
are these effects adaptive for oxygen unloading in the tissues?
30. Describe the effects of increased DPG on the oxygen-
hemoglobin dissociation curve. What is the adaptive
importance of the effect of DPG on the curve?
31. Draw fi gures showing the reactions carbon dioxide undergoes
entering the blood in the tissue capillaries and leaving the
blood in the alveoli. What fractions are contributed by dissolved
carbon dioxide, bicarbonate, and carbamino-hemoglobin?
32. What happens to most of the hydrogen ions formed in the
erythrocytes from carbonic acid? What happens to blood H
+
concentration as blood fl ows through tissue capillaries?
33. What are the effects of
P
O
2
on carbamino-hemoglobin
formation and H
+
binding by hemoglobin?
34. Describe the area of the brain in which automatic control of
rhythmical respirations resides.
35. Describe the function of the pulmonary stretch receptors.
36. What changes stimulate the peripheral chemoreceptors? The
central chemoreceptors?
37. Why doesn’t moderate anemia or carbon monoxide exposure
stimulate the peripheral chemoreceptors?
38. Is respiratory control more sensitive to small changes in arterial
P
O
2
or in arterial
P
CO
2
?
39. Describe the pathways by which increased arterial
P
CO
2
stimulates ventilation. What pathway is more important?
40. Describe the pathway by which a change in arterial H
+
concentration independent of altered carbon dioxide infl uences
ventilation. What is the adaptive value of this refl ex?
41. What happens to arterial
P
O
2
,
P
CO
2
, and H
+
concentration
during moderate and strenuous exercise? List other factors that
may stimulate ventilation during exercise.
42. List four general causes of hypoxic hypoxia.
43. Explain how ventilation-perfusion mismatch due to regional
lung disease can cause hypoxic hypoxia but not hypercapnia.
44. Describe two general ways in which the lungs can alter the
concentrations of substances other than oxygen, carbon
dioxide, and H
+
in the arterial blood.
45.
List two types of sleep apnea. Why does nasal CPAP prevent
obstructive sleep apnea?
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