Florida International University

BIO PCB 4023

Chapter 17

1)The respiratory quotient is calculated as the

1. 1. sum of the volume of oxygen consumed and the volume of carbon dioxide produced.
   2. product of the volume of oxygen consumed and the volume of carbon dioxide produced.
   3. ratio of the volume of oxygen consumed per volume of carbon dioxide produced.
   4. product of the volume of carbon dioxide consumed and the volume of oxygen produced.
   5. ratio of the volume of carbon dioxide produced per volume of oxygen consumed.
2. At sea level, if oxygen is consumed by the body cells at a rate of 300 mL per minute, then how much oxygen diffuses from the alveoli into the blood in the pulmonary capillaries?
   1. 300 mL per minute
   2. more than 300 mL per minute
   3. less than 300 mL per minute
   4. It depends on where the oxygen is being utilized.
   5. It depends on whether or not carbon dioxide is being produced at the same rate.
3. Oxygenated blood is found in which of the following?
   1. right atrium only
   2. pulmonary artery only
   3. pulmonary vein only
   4. both the right atrium and pulmonary artery
   5. both the right atrium and pulmonary vein
4. Movement of oxygen and carbon dioxide between alveoli and blood occurs by what process?
   1. osmosis
   2. simple diffusion
   3. facilitated diffusion
   4. primary active transport
   5. secondary active transport
5. Which of the following does NOT contribute to the rapid movement of gases into and out of the blood within the lungs?
   1. thin membrane
   2. rapid blood flow
   3. permeability of the membrane
   4. large surface area
   5. concentration gradient

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6. At sea level the air pressure which equals 1 atmosphere is
   1. 150 mm Hg.
   2. 100 mm Hg.
   3. 600 mm Hg.
   4. 500 mm Hg.
   5. 760 mm Hg.

7. In a mixture of gases, the driving force for the movement of an individual gas within that mixture is ultimately the
   1. total pressure of the gases.
   2. volume of the gas.
   3. partial pressure of that gas.
   4. fractional concentration of that gas.
   5. solubility of the gas.

8. What is the most abundant gas in the air that we breathe?

8. 1. carbon dioxide
   2. oxygen
   3. hydrogen
   4. water vapor
   5. nitrogen
9. What percentage of air is oxygen?

A) 79% B) 6% C) 12% D) 21% E) < 1%

10. What percentage of air is carbon dioxide? A) 6% B) 79% C) 12% D) < 1% E) 21%
11. What is the partial pressure of oxygen in a gas mixture that is 40% oxygen, 40% argon, and 20% helium, when the total pressure of the gas is 1000 mm Hg?
    1. 333 mm Hg B) 600 mm Hg C) 400 mm Hg D) 100 mm Hg E) 200 mm Hg
12. What is the partial pressure of oxygen in air at sea level?
    1. 160 mm Hg B) 210 mm Hg C) 400 mm Hg D) 60 mm Hg E) 600 mm Hg
13. As humidity increases, the partial pressure of oxygen in air
    1. increases as the total pressure of air remains the same.
    2. increases as the total pressure of air increases.
    3. decreases as the total pressure of air remains the same.
    4. decreases as the total pressure of air increases.
    5. does not change.

14. As the air is saturated with water vapor (humidified) upon entry into the conducting pathway, there will be
    1. a selective increase in the partial pressure of nitrogen.
    2. a selective decrease in the partial pressure of nitrogen.
    3. an increase in the partial pressure of the remaining gases.
    4. no change in the partial pressure of the remaining gases.
    5. a decrease in the partial pressure of the remaining gases.
15. At equilibrium, the gas molecules that dissolve in solution and those that remain in the gaseous phase are, by definition, at the same
    1. concentration.
    2. temperature.
    3. volume.
    4. humidity.
    5. partial pressure.
16. The relationship between the concentration of a gas in solution and the partial pressure of that gas can be described by
    1. Fick's law.
    2. Poiseuille's law.
    3. Dalton's law.
    4. Boyle's law.
    5. Henry's law.
17. Which of the following can increase the concentration of a particular gas in a solution?
    1. Increase the volume of the gas only.
    2. Increase the volume of the container containing the gas and solution.
    3. Increase the volume of the solution only.
    4. Decrease the concentration of other gases in the solution.
    5. Increase the partial pressure of that gas exposed to the solution.

18. At equilibrium, which of the following statements is TRUE when helium and nitrogen are present in a gas at equal partial pressures over water?
    1. The partial pressure of nitrogen is greater than the partial pressure of helium.
    2. The concentrations of helium and nitrogen in the gas are equal.
    3. The concentrations of helium and nitrogen in the water are equal.
    4. The partial pressures of helium and nitrogen in the water are equal.
    5. The concentrations of helium and nitrogen in both the water and gas are equal.

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19. Which statement best describes why O2 and CO2 can both be exchanged simultaneously at the alveoli and pulmonary capillaries?
    1. Nitrogen is at a high pressure in both the alveoli and pulmonary capillaries and drives the exchange of O2 and CO2.
    2. Blood in both the alveoli and pulmonary capillaries is at equilibrium.
    3. Each gas acts independently and diffuses down its own partial pressure gradient.
    4. Blood in the pulmonary capillaries is high in both O2 and CO2.
    5. Blood in the alveoli is high in both O2 and CO2.
20. Which statement best describes the cause of decompression sickness?
    1. Oxygen molecules are so tightly compressed due to pressure exerted by the water column that they cannot deliver oxygen to the tissues.
    2. The oxygen molecule expands upon ascent and bursts, therefore causing a lack of oxygen to the tissues.
    3. Carbon dioxide is driven into the cardiovascular system and causes acidosis.
    4. Nitrogen gas bubbles form in the blood, joints, and nervous system as pressure decreases from too fast an ascent.
    5. Carbon dioxide bubbles come out of solution too quickly and burst blood vessels, especially in the brain.

21. Gangrene is often caused by anaerobic bacteria deep in tissues that lack adequate blood flow and adequate oxygen supply. Many times, gangrene can be treated by putting the patient into a hyperbaric chamber. Which statement best describes why this type of therapy is effective?
    1. The increased pressure drives nitrogen into the system and nitrogen gas poisons the bacteria.
    2. The increased pressure drives more oxygen into the bloodstream and, therefore, anaerobic bacteria cannot survive in the presence of oxygen.
    3. The increased pressure creates a higher pressure in the capillaries of the tissue and drives the toxin produced by the bacteria into the bloodstream, where it is diluted.
    4. The increased pressure destroys the cell wall of the bacteria.
    5. When the patient is brought back to normal atmospheric pressure, carbon dioxide comes out of solution at high concentrations, which poisons the bacteria.

22. The mixing of atmospheric air within the dead space of the conducting zone of the lung upon inspiration results in a partial pressure of
    1. oxygen in the alveoli that is higher than atmospheric.
    2. nitrogen in the alveoli that is higher than atmospheric.
    3. oxygen in the alveoli that is lower than atmospheric.
    4. carbon dioxide in the alveoli that is lower than atmospheric.
    5. water vapor in the alveoli that is lower than atmospheric.
23. Which of the following causes a decrease in the PO2 of air as it enters the conducting zone of the lungs?
    1. warming of the air
    2. decreasing alveolar PO2
    3. the consumption of oxygen
    4. humidifying the air
    5. the increasing PCO2

24. Pulmonary edema describes a condition where the uptake of oxygen and unloading of carbon dioxide is reduced as a consequence of a(n)
    1. decrease in the partial pressure of carbon dioxide in the alveolus.
    2. increase in the partial pressure of oxygen in the blood.
    3. thickening of the diffusion barrier by fluid accumulation in the pulmonary blood.
    4. thickening of the diffusion barrier by fluid accumulation in the alveoli.
    5. decrease in the partial pressure of oxygen in the alveolus.
25. Your patient is in the hospital due to left heart failure. In your observation, you notice that she has a very low pulse oximeter reading, her skin is turning blue, and she appears to be in respiratory distress (rapid shallow breathing). You immediately call the doctor because you recognize that these symptoms indicate                                                                                                                                  ,a life- threatening situation.
    1. internal bleeding
    2. decompression sickness
    3. myocardial infarction
    4. prolapsed heart valve
    5. pulmonary edema
26. What is the most common cause of pulmonary edema?
    1. collapsed lung
    2. blood clot
    3. kidney failure
    4. right heart failure
    5. left heart failure
27. During intense exercise, the metabolic activity of muscle causes         in the partial pressure of oxygen in the tissue,                                                                         the movement of oxygen into the tissue.
    1. a decrease : facilitating
    2. a decrease : reducing
    3. no change : facilitating
    4. an increase : reducing
    5. an increase : facilitating

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28. Mixed venous blood samples can be taken from which of the following blood vessels?
    1. pulmonary vein
    2. inferior vena cava
    3. pulmonary artery
    4. aorta
    5. superior vena cava
29. The venous blood in the right ventricle is referred to as "mixed" because the blood that enters the heart
    1. is drained from the body.
    2. comes from tissue with differing metabolic activities.
    3. contains a mixture of oxygen and carbon dioxide.
    4. has a low PO2.
    5. has a high PCO2.
30. What is an increase in alveolar ventilation to match the demands of increased metabolic activity in the cells called?
    1. hypoventilation
    2. hyperventilation
    3. hyperpnea
    4. dyspnea
    5. hypopnea

31. Hyperventilation would lead to a(n)     within the systemic arteries.
    1. increase in PO2 and decrease in PCO2
    2. selective decrease in PO2
    3. selective decrease in PCO2
    4. selective increase in PO2
    5. decrease in PO2 and increase in PCO2

32. Hypoventilation would lead to a(n)      within the systemic arteries.
    1. increase in PO2 and decrease in PCO2
    2. selective increase in PO2
    3. selective decrease in PCO2
    4. decrease in PO2 and increase in PCO2
    5. selective decrease in PO2

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33. What is a decrease in carbon dioxide within the blood called?
    1. hypoxia
    2. hypercapnia
    3. hypoxemia
    4. hypocapnia
    5. hyperpnea
34. What percentage of oxygen is transported in the plasma? A) 86% B) 5% C) 75% D) 1.5% E) 98.5%

35. What percentage of oxygen is transported by hemoglobin? A) 75% B) 98.5% C) 86% D) 1.5% E) 5%

36. The majority of oxygen present within the blood is
    1. bound to hemoglobin within the plasma.
    2. bound to plasma proteins.
    3. dissolved within the plasma.
    4. in the plasma as HCO3-.
    5. bound to hemoglobin in red blood cells.
37. Each              on the hemoglobin subunit is capable of binding an oxygen molecule, thereby allowing oxygen to bind with one hemoglobin molecule.
    1. globin : four
    2. heme : four
    3. globin : three
    4. heme : three
    5. free iron : one
38. What is the primary driving force for the binding of oxygen to hemoglobin?
    1. PO2
    2. PCO2
    3. pH
    4. temperature
    5. 2,3-bisphosphoglycerate (2,3-BPG)

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39. Which statement best describes why the law of mass action explains the loading and unloading of oxygen in hemoglobin?
    1. Oxygen has a greater mass than carbon dioxide and therefore can load more quickly than carbon dioxide.
    2. As oxygen levels in the pulmonary capillaries increase, more oxyhemoglobin is formed. Conversely, as

oxygen levels in the systemic capillaries decrease, the reaction reverses and releases oxygen from hemoglobin.

1. 3. The mass of both carbon dioxide and oxygen is the same and therefore they exchange at the same rates
   4. As oxygen level rises, so does the pressure, which breaks the bonds of hemoglobin thereby releasing hemoglobin to the tissues.
   5. As oxygen levels in the pulmonary capillaries decrease, more carbaminohemoglobin is formed due to the concentration of carbon dioxide.

40. If hemoglobin is saturated (1.3 mL of oxygen per gram) and there are 150 grams of hemoglobin per liter of blood, how much oxygen can be delivered to the tissue if cardiac output is 15 liters per minute?
    1. 2925 g O2/min
    2. 2925 mL O2/min
    3. 1300 g O2/min
    4. 650 g O2/min
    5. 1300 mL O2/min
41. What is the definition of anemia?
    1. a decrease in the oxygen carrying capacity of the blood
    2. a decrease in hemoglobin
    3. an increase in PCO2
    4. a decrease in the affinity of hemoglobin for oxygen
    5. a decrease in PO2

42. What is labored or difficult breathing called?
    1. hyperpnea B) eupnea C) hypopnea D) dyspnea E) apnea
43. What is a deficiency of oxygen in the tissues called?
    1. hypercapnia
    2. hypoxia
    3. hypoxemia
    4. hypocapnia
    5. apnea
44. What is rapid shallow breathing called?
    1. dyspnea B) hyperpnea C) tachypnea D) eupnea E) apnea

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45. What is a decrease in oxygen in the blood called?
    1. hypoxemia B) hypocapnia C) hypoxia D) dysnemia E) anemia
46. As oxygen binds to hemoglobin, the      of the hemoglobin molecule will change through a process of  such that the binding of oxygen is enhanced.
    1. amino acid sequence : phosphorylation
    2. cooperativity : negativity
    3. affinity : positive cooperativity
    4. affinity : negative cooperativity
    5. cooperativity : positivity
47. Which of the following statements is FALSE regarding a leftward shift in the hemoglobin-oxygen dissociation curve?
    1. Hemoglobin is more saturated at a given PO2.
    2. Affinity for oxygen is increased.
    3. Oxygen loading onto the hemoglobin is increased.
    4. It can be caused by an increase in PCO2.
    5. It can be caused by an increase in blood pH.

48. Which of the following statements is FALSE regarding a rightward shift in the hemoglobin-oxygen dissociation curve?
    1. Affinity for oxygen is decreased.
    2. Hemoglobin unloading of oxygen is increased.
    3. It can be caused by a decrease in 2,3-BPG.
    4. Oxygen loading onto hemoglobin is decreased.
    5. A rightward shift usually occurs in active tissue.
49. Which of the following will cause a shift in the hemoglobin-oxygen dissociation curve to the right?
    1. increase in temperature only
    2. increase in plasma pH only
    3. increase in 2,3-BPG (2,3-bisphosphoglycerate) only
    4. both an increase in temperature and an increase in 2,3-BPG
    5. both an increase in temperature and an increase in plasma pH
50. As it leaves the lung in the pulmonary vein, blood is saturated with oxygen. A) 90%

B) 98%

3. 108% (supersaturated)
4. 100% (completely)

E) 75%

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51. Which of the following increases oxygen unloading from hemoglobin?
    1. increased oxygen levels in the tissue
    2. increased blood pH
    3. decreased metabolism
    4. decreased temperature
    5. increased carbon dioxide in the tissue
52. Which of the following will increase the unloading of oxygen within the tissue?
    1. increased hydrogen ion concentration only
    2. increased PCO2 only
    3. increased body temperature only
    4. both increased hydrogen ion concentration and increased body temperature
    5. increased hydrogen ion concentration, increased body temperature, and increased PCO2

53. Which of the following will increase the loading of oxygen onto the hemoglobin molecule within the lungs?
    1. decreased pH
    2. decreased hydrogen ion concentration
    3. increased PCO2
    4. increased 2,3-bisphosphoglycerate (2,3-BPG)
    5. increased body temperature
54. In the systemic arteries, the partial pressure of oxygen is approximately        , and hemoglobin is approximately        saturated with oxygen.
    1. 40 mm Hg : 75%

B) 100 mm Hg : 75%

3. 60 mm Hg : 50%
4. 40 mm Hg : 50%

E) 100 mm Hg : 98%

55. In the pulmonary arteries, the partial pressure of oxygen is approximately     , and hemoglobin is approximately           saturated with oxygen.

A) 100 mm Hg : 98%

2. 40 mm Hg : 75%

3. 80 mm Hg : 90%
4. 25 mm Hg : 50%
5. 60 mm Hg : 80%

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56. Which statement best describes why oxygen is unloaded in tissue that is highly active?
    1. As temperature increases due to increased metabolism, the affinity of hemoglobin for oxygen is decreased.
    2. As temperature increases, the carbamino effect causes hemoglobin to release oxygen.
    3. As temperature increases, the Bohr effect causes hemoglobin to release oxygen.
    4. Highly active tissues produce more carbon dioxide, which competes for the heme groups in hemoglobin, thereby displacing oxygen.
    5. As temperature increases, the affinity for oxygen to hemoglobin increases, allowing more oxygen to be carried to the tissues.

57. Which statement best describes the Bohr effect?
    1. The Bohr effect speeds up metabolism and therefore increases the temperature in the body releasing oxygen to the tissues.
    2. The Bohr effect refers to a decrease in pH which decreases the affinity of hemoglobin for oxygen.
    3. The Bohr effect refers to the cascading events that must take place in order to chemically remove oxygen from hemoglobin.
    4. The Bohr effect refers to the release of a chemical 2,3 BPG from erythrocytes that degrades hemoglobin and releases oxygen.
    5. The Bohr effect refers to a decrease in carbon dioxide concentration which decreases the affinity of hemoglobin for oxygen.

58. The carbamino effect describes a change in the conformation of hemoglobin that is induced by a(n)
    1. decrease in temperature.
    2. increase in pH.
    3. decrease in pH.
    4. increase in CO2.
    5. increase in temperature.
59. Which of the following statements about 2,3-BPG is FALSE?
    1. 2,3-BPG is produced by red blood cells.
    2. 2,3-BPG produces a rightward shift in the hemoglobin-oxygen dissociation curve.
    3. 2,3-BPG increases the affinity of hemoglobin for oxygen.
    4. 2,3-BPG is an intermediate of glycolysis.
    5. 2,3-BPG synthesis is inhibited by high levels of oxyhemoglobin.
60. Where in blood does the conversion of CO2 to bicarbonate occur?
    1. capillary endothelial cells
    2. plasma
    3. leukocytes
    4. platelets
    5. erythrocytes

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61. What is the primary mechanism of carbon dioxide transport in blood?
    1. bound to hemoglobin
    2. as bicarbonate dissolved in the red blood cells
    3. as bicarbonate dissolved in the plasma
    4. dissolved in the red blood cells
    5. dissolved in the plasma
62. Which statement best describes how people die of carbon monoxide poisoning?

1. 1. As the carbon dioxide content of blood increases, a phenomenon known as the Haldane effect converts the excess carbon dioxide to carbon monoxide until it reaches toxic levels.
   2. Carbon monoxide is toxic because it binds more readily to hemoglobin than oxygen, thereby decreasing the oxygen carrying capacity of blood.
   3. Carbon monoxide causes the carbamino effect where carbon dioxide is stripped of an oxygen, producing carbon monoxide.
   4. Carbon monoxide causes decompression sickness which can lead to death.
   5. Carbon monoxide is toxic because it readily picks up oxygen to produce carbon dioxide, causing acidosis and eventual death.

63. The presence of bicarbonate ions in the blood has an important direct effect, aside from the transport of CO2, that involves
    1. altering the affinity of hemoglobin for oxygen.
    2. stimulating the proliferation of alveolar epithelial cells.
    3. altering the activity of carbonic anhydrase.
    4. altering the activity of several receptors.
    5. maintaining acid-base balance.
64. Within an erythrocyte, the conversion of CO2 to bicarbonate is prevented from reaching equilibrium by the
    1. temperature of the body.
    2. absence of a nucleus.
    3. presence of oxygen.
    4. efflux of bicarbonate from the erythrocyte via the chloride shift.
    5. presence of hydrogen ions.
65. The hydrogen ions released by the dissociation of carbonic acid are buffered by their
    1. binding to hemoglobin.
    2. transport into the erythrocyte as sodium ions move out.
    3. binding to DNA within the nucleus.
    4. transport out of the erythrocyte as a sodium ion moves in.
    5. active transport out of the erythrocyte.

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66. The Haldane effect describes the increase in the affinity of hemoglobin for CO2 in the presence of a lowered
    1. pH.
    2. PCO2.
    3. concentration of bicarbonate (HCO3-).
    4. temperature.
    5. PO2.
67. During quiet breathing, a person's breathing cycle consists of
    1. contraction of inspiratory muscles.
    2. contraction and relaxation of inspiratory and expiratory muscles.
    3. contraction of expiratory muscles.
    4. contraction of inspiratory muscles and relaxation of expiratory muscles.
    5. contraction and relaxation of inspiratory muscles.
68. Which of the following nerves has activity during quiet inspiration?
    1. phrenic nerve only
    2. internal intercostal nerve only
    3. external intercostal nerve only
    4. both the phrenic nerve and internal intercostal nerves
    5. both the phrenic nerve and external intercostal nerves
69. During active breathing, bursts of action potentials are observed to occur
    1. synchronously in the inspiratory and expiratory motor neurons.

69. 2. exclusively in the inspiratory motor neurons.
    3. exclusively in the expiratory motor neurons.
    4. asynchronously in the inspiratory and expiratory motor neurons.
    5. simultaneously in the inspiratory and expiratory motor neurons.
70. The              is the respiratory center that appears to facilitate the transition between inspiration and expiration.
    1. ventral respiratory group
    2. central pattern generator
    3. dorsal respiratory group
    4. pontine respiratory group
    5. medullary respiratory group
71. In the model for quiet breathing, expiration is induced by
    1. activation of expiratory neurons in the ventral respiratory center.
    2. abrupt termination of inspiration.
    3. activation of inspiratory neurons in the ventral respiratory center.
    4. activation of expiratory neurons in the dorsal respiratory center.
    5. activation of inspiratory neurons in the dorsal respiratory center.

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72. Coughing is initiated by         located in the          .
    1. stretch receptor : trachea
    2. chemoreceptors : trachea
    3. irritant receptors : nose and pharynx
    4. irritant receptors : trachea
    5. chemoreceptors : nose and pharynx
73. Peripheral chemoreceptors are specialized cells in contact with arterial blood that respond directly to changes in blood
    1. pH.
    2. PO2.
    3. PCO2.
    4. PCO2 and PO2.
    5. PO2, pH, and PCO2.
74. Central chemoreceptors are neurons in the medulla that respond directly to changes in
    1. blood pH.
    2. cerebrospinal fluid pH.
    3. blood pH and PO2.
    4. cerebrospinal fluid PO2.
    5. cerebrospinal fluid PO2 and pH.
75. Chemoreceptors respond primarily to changes in PCO2 indirectly by its effect on
    1. hydrogen ion concentration.
    2. hemoglobin concentration.
    3. 2,3-diphosphoglycerate (2,3-DPG) concentration.
    4. lactic acid concentration.
    5. PO2.
76. Hyperventilation will cause changes in PCO2 that are detected by the chemoreceptors which causes a(n)
    1. decrease in breathing rate only.
    2. increase in breathing rate and depth of breathing.
    3. decrease in breathing rate and depth of breathing.
    4. increase in breathing rate only.
    5. increase in depth of breathing only.

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77. Which of the following best describes a chemoreceptor response to PO2?
    1. Peripheral chemoreceptors respond to oxyhemoglobin.
    2. Central chemoreceptors respond to only large decreases in PO2.
    3. Peripheral chemoreceptors respond to small changes in PO2.
    4. Peripheral chemoreceptors respond only indirectly to PO2.
    5. Central chemoreceptors do not respond to changes in PO2.
78. A decrease in PCO2 within the lung will result in a  in the pulmonary vasculature and a    in the bronchioles.
    1. lack of change : weak bronchoconstriction
    2. weak vasoconstriction : bronchodilation
    3. weak vasodilation : bronchoconstriction
    4. vasoconstriction : lack of change
    5. vasodilation : weak bronchodilation
79. A local bronchodilation within the alveolus will result in a(n)                     in the ventilation-perfusion ratio in that region. A vasoconstriction of pulmonary arteriole diameter will result in a(n)           in the

ventilation-perfusion ratio in that region.

79. 1. lack of change : increase
    2. increase : increase
    3. increase : decrease
    4. decrease : increase
    5. decrease : decrease
80. The primary effect of increased PO2 in the lungs is to cause                     which     the ventilation-perfusion ratio back to a normal level.
    1. vasoconstriction : increases
    2. vasodilation : decreases
    3. vasoconstriction : decreases
    4. bronchoconstriction : decreases
    5. bronchodilation : increases
81. The primary effect of increased PCO2 in the lungs is to cause                     which        the ventilation-perfusion ratio back to a normal level.
    1. bronchodilation : increases
    2. vasoconstriction : decreases
    3. vasoconstriction : increases
    4. bronchoconstriction : decreases
    5. vasodilation : decreases

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82. What is the normal pH range for blood?

A) 7.38-7.42 B) 7-10 C) 1-14 D) 7.35-7.45 E) 7

83. Which statement best describes the effect on the body due to pH changes either above or below the normal range?
    1. pH ranges vary throughout the body; therefore, blood pH has no detrimental effects on the body as it changes pH.
    2. Changes in pH can denature proteins that serve as enzymes and receptors throughout the body, resulting in widespread effects on the body.
    3. Changes in pH destroy the nephrons of the kidney, making kidney failure is inevitable.
    4. Changes in pH can only lower pH causing acidosis, meaning organs deteriorate due to high levels of acid.
    5. Changes in pH out of the normal range are normal and will not have any detrimental effects on the

body.

84. When the blood becomes       , it can lead to a depression in the activity of the central nervous system.
    1. hypoxic B) alkaline C) hypocapnic D) acidic E) pH 7.4
85. The buffering capacity of hemoglobin is directly related to its ability to bind with
    1. oxygen.
    2. carbon monoxide.
    3. carbon dioxide.
    4. hydrogen ions.
    5. nitrogen.
86. Bicarbonate is an important buffer in blood and its concentration is regulated by the
    1. heart. B) lungs. C) liver. D) kidneys. E) pancreas.
87. A change in the ratio of bicarbonate to carbon dioxide concentration in the blood will
    1. cause a vasodilation of systemic arterioles.
    2. change blood pH.
    3. change blood potassium concentration.
    4. cause a bronchodilation.
    5. change blood chloride concentration.
88. Respiratory acidosis will result from a(n)
    1. increase in blood bicarbonate.
    2. increase in blood CO2 concentration.
    3. decrease in blood CO2 concentration.
    4. increase in carbon monoxide.
    5. decrease in blood bicarbonate.

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89. Assuming resting conditions at sea level, what is the partial pressure of oxygen in air?
    1. 160 mm Hg B) 100 mm Hg C) 80 mm Hg D) 46 mm Hg E) 40 mm Hg
90. Assuming resting conditions at sea level, what is the partial pressure of oxygen in alveoli?
    1. 46 mm Hg B) 100 mm Hg C) 160 mm Hg D) 80 mm Hg E) 40 mm Hg
91. Assuming resting conditions at sea level, what is the partial pressure of carbon dioxide in alveoli?
    1. 100 mm Hg B) 80 mm Hg C) 46 mm Hg D) 40 mm Hg E) 160 mm Hg
92. Assuming resting conditions at sea level, what is the partial pressure of oxygen in pulmonary veins?
    1. 160 mm Hg B) 46 mm Hg C) 80 mm Hg D) 40 mm Hg E) 100 mm Hg
93. Assuming resting conditions at sea level, what is the partial pressure of carbon dioxide in pulmonary veins?
    1. 100 mm Hg B) 40 mm Hg C) 80 mm Hg D) 160 mm Hg E) 46 mm Hg
94. Assuming resting conditions at sea level, what is the partial pressure of oxygen in systemic arteries?
    1. 46 mm Hg B) 100 mm Hg C) 80 mm Hg D) 40 mm Hg E) 160 mm Hg
95. Assuming resting conditions at sea level, what is the partial pressure of carbon dioxide in systemic arteries?
    1. 80 mm Hg B) 100 mm Hg C) 40 mm Hg D) 46 mm Hg E) 160 mm Hg
96. Assuming resting conditions at sea level, what is the partial pressure of oxygen in systemic veins?
    1. 160 mm Hg B) 100 mm Hg C) 80 mm Hg D) 46 mm Hg E) 40 mm Hg
97. Assuming resting conditions at sea level, what is the partial pressure of carbon dioxide in systemic veins?
    1. 46 mm Hg B) 40 mm Hg C) 160 mm Hg D) 80 mm Hg E) 100 mm Hg

98. Assuming resting conditions at sea level, what is the partial pressure of oxygen in pulmonary arteries?
    1. 46 mm Hg B) 160 mm Hg C) 40 mm Hg D) 80 mm Hg E) 100 mm Hg
99. A decrease in the affinity of hemoglobin for oxygen caused by the binding of carbon dioxide to hemoglobin is described by the
    1. Haldane effect.
    2. Bohr effect.
    3. carbamino effect.
    4. Henderson-Hasselbalch effect.
    5. respiratory quotient.

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100. A decrease in the affinity of hemoglobin for oxygen caused by the binding of a hydrogen ion to hemoglobin is described by the

1. Henderson-Hasselbalch effect.
2. Bohr effect.
3. carbamino effect.
4. respiratory quotient.
5. Haldane effect.

101. A decrease in the affinity of hemoglobin for carbon dioxide caused by the binding of oxygen to hemoglobin is described by the

1. carbamino effect.
2. Henderson-Hasselbalch effect.
3. respiratory quotient.
4. Bohr effect.
5. Haldane effect.

102. At an altitude where atmospheric pressure is 500 mm Hg, what is the partial pressure of oxygen?

A) 100 mm Hg B) 105 mm Hg C) 630 mm Hg D) 760 mm Hg E) 800 mm Hg

103. A decrease in the affinity of oxygen for hemoglobin is reflected as a              shift in the hemoglobin-oxygen dissociation curve, which would facilitate the of oxygen.

1. rightward : loading
2. rightward : unloading
3. leftward : loading
4. leftward : unloading
5. neutral : loading

104. What is the partial pressure of nitrogen if it accounts for 20% of a mixed gas with a total pressure of 1000 mm Hg?

A) 10 mm Hg B) 200 mm Hg C) 20 mm Hg D) 100 mm Hg E) 0 mm Hg

105. Respiratory acidosis can occur during

1. the Haldane effect.
2. hyperpnea.
3. hypocapnia.
4. hyperventilation.
5. hypoventilation.

106. The air that we breathe is composed of three essential gases that include nitrogen, oxygen, and water vapor.

Describe the physical properties that govern the diffusion of gases, including partial pressure and gas solubility.

107. The exchange of gases occurs primarily within the lungs and tissues. Describe the nature of the movement of gases in the lungs (including how the partial pressure of alveolar gases are determined) and tissues.