Chapter 17
40) At an altitude where atmospheric pressure is 500 mm Hg, what is the partial pressure of oxygen? 40) A) 105 mm Hg B) 760 mm Hg C) 630 mm Hg D) 800 mm Hg E) 100 mm Hg
A) 105 mm Hg
45) What is the partial pressure of oxygen in air at sea level? 45) A) 160 mm Hg B) 60 mm Hg C) 210 mm Hg D) 400 mm Hg E) 600 mm Hg
A) 160 mm Hg
78) Which of the following statements about 2,3-BPG is FALSE? 78) A) 2,3-BPG increases the affinity of hemoglobin for oxygen. B) 2,3-BPG is produced by red blood cells. C) 2,3-BPG produces a rightward shift in the hemoglobin-oxygen dissociation curve. D) 2,3-BPG synthesis is inhibited by high levels of oxyhemoglobin. E) 2,3-BPG is an intermediate of glycolysis.
A) 2,3-BPG increases the affinity of hemoglobin for oxygen.
56) What is the partial pressure of nitrogen if it accounts for 20% of a mixed gas with a total pressure of 56) 1000 mm Hg? A) 200 mm Hg B) 10 mm Hg C) 0 mm Hg D) 20 mm Hg E) 100 mm Hg
A) 200 mm Hg
84) If hemoglobin is saturated (1.3 mL of oxygen per gram) and there are 150 grams of hemoglobin per 84) liter of blood, how much oxygen can be delivered to the tissue if cardiac output is 15 liters per minute? A) 2925 mL Ó/min B) 650 g Ó/min C) 2925 g Ó/min D) 1300 mL Ó/min E) 1300 g Ó/min
A) 2925 mL O2/min
44) At sea level, if oxygen is consumed by the body cells at a rate of 300 mL per minute, then how 44) much oxygen diffuses from the alveoli into the blood in the pulmonary capillaries? A) 300 mL per minute B) more than 300 mL per minute C) less than 300 mL per minute D) It depends on where the oxygen is being utilized. E) It depends on whether or not carbon dioxide is being produced at the same rate.
A) 300 mL per minute
23) Assuming resting conditions at sea level, what is the partial pressure of carbon dioxide in 23) pulmonary veins? A) 40 mm Hg B) 100 mm Hg C) 46 mm Hg D) 80 mm Hg E) 160 mm Hg
A) 40 mm Hg
5) Assuming resting conditions at sea level, what is the partial pressure of carbon dioxide in systemic 5) arteries? A) 40 mm Hg B) 100 mm Hg C) 80 mm Hg D) 46 mm Hg E) 160 mm Hg
A) 40 mm Hg
95) Assuming resting conditions at sea level, what is the partial pressure of oxygen in systemic veins? 95) A) 40 mm Hg B) 100 mm Hg C) 80 mm Hg D) 160 mm Hg E) 46 mm Hg
A) 40 mm Hg
04) What percentage of air is carbon dioxide? 104) A) < 1% B) 12% C) 21% D) 6% E) 79%
A) < 1%
76) Which statement best describes why O2 and CO2 can both be exchanged simultaneously at the 76) alveoli and pulmonary capillaries? A) Each gas acts independently and diffuses down its own partial pressure gradient. B) Nitrogen is at a high pressure in both the alveoli and pulmonary capillaries and drives the exchange of O2 and CO2. C) Blood in the pulmonary capillaries is high in both O2 and CO2. D) Blood in both the alveoli and pulmonary capillaries is at equilibrium. E) Blood in the alveoli is high in both O2 and CO2.
A) Each gas acts independently and diffuses down its own partial pressure gradient.
102) Which of the following statements is FALSE regarding a leftward shift in the hemoglobin-oxygen 102) dissociation curve? A) It can be caused by an increase in PCÓ. B) Hemoglobin is more saturated at a given PÓ. C) Affinity for oxygen is increased. D) It can be caused by an increase in blood pH. E) Oxygen loading onto the hemoglobin is increased.
A) It can be caused by an increase in PCO2.
47) Which statement best describes the cause of decompression sickness? 47) A) Nitrogen gas bubbles form in the blood, joints, and nervous system as pressure decreases from too fast an ascent. B) Oxygen molecules are so tightly compressed due to pressure exerted by the water column that they cannot deliver oxygen to the tissues. C) Carbon dioxide bubbles come out of solution too quickly and burst blood vessels, especially in the brain. D) Carbon dioxide is driven into the cardiovascular system and causes acidosis. E) The oxygen molecule expands upon ascent and bursts, therefore causing a lack of oxygen to the tissues.
A) Nitrogen gas bubbles form in the blood, joints, and nervous system as pressure decreases from too fast an ascent.
10) Which statement best describes the Bohr effect? 10) A) The Bohr effect refers to a decrease in pH which decreases the affinity of hemoglobin for oxygen. B) The Bohr effect speeds up metabolism and therefore increases the temperature in the body releasing oxygen to the tissues. C) The Bohr effect refers to a decrease in carbon dioxide concentration which decreases the affinity of hemoglobin for oxygen. D) The Bohr effect refers to the cascading events that must take place in order to chemically remove oxygen from hemoglobin. E) The Bohr effect refers to the release of a chemical 2,3 BPG from erythrocytes that degrades hemoglobin and releases oxygen.
A) The Bohr effect refers to a decrease in pH which decreases the affinity of hemoglobin for oxygen.
89) Gangrene is often caused by anaerobic bacteria deep in tissues that lack adequate blood flow and 89) 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? A) The increased pressure drives more oxygen into the bloodstream and, therefore, anaerobic bacteria cannot survive in the presence of oxygen. B) The increased pressure drives nitrogen into the system and nitrogen gas poisons the bacteria. C) When the patient is brought back to normal atmospheric pressure, carbon dioxide comes out of solution at high concentrations, which poisons the bacteria. D) 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. E) The increased pressure destroys the cell wall of the bacteria.
A) The increased pressure drives more oxygen into the bloodstream and, therefore, anaerobic bacteria cannot survive in the presence of oxygen.
49) As the air is saturated with water vapor (humidified) upon entry into the conducting pathway, 49) there will be A) a decrease in the partial pressure of the remaining gases. B) no change in the partial pressure of the remaining gases. C) an increase in the partial pressure of the remaining gases. D) a selective increase in the partial pressure of nitrogen. E) a selective decrease in the partial pressure of nitrogen.
A) a decrease in the partial pressure of the remaining gases.
54) In the model for quiet breathing, expiration is induced by A) abrupt termination of inspiration. B) activation of expiratory neurons in the dorsal respiratory center. C) activation of expiratory neurons in the ventral respiratory center. D) activation of inspiratory neurons in the ventral respiratory center. E) activation of inspiratory neurons in the dorsal respiratory center.
A) abrupt termination of inspiration.
53) As oxygen binds to hemoglobin, the ________ of the hemoglobin molecule will change through a 53) process of ________ such that the binding of oxygen is enhanced. A) affinity : positive cooperativity B) amino acid sequence : phosphorylation C) cooperativity : positivity D) affinity : negative cooperativity E) cooperativity : negativity
A) affinity : positive cooperativity
99) The majority of oxygen present within the blood is A) bound to hemoglobin in red blood cells. B) dissolved within the plasma. C) bound to plasma proteins. D) bound to hemoglobin within the plasma. E) in the plasma as HCǑ-.
A) bound to hemoglobin in red blood cells.
52) The primary effect of increased PCO2 in the lungs is to cause ________ which ________ the 52) ventilation-perfusion ratio back to a normal level. A) bronchodilation : increases B) vasoconstriction : increases C) bronchoconstriction : decreases D) vasodilation : decreases E) vasoconstriction : decreases
A) bronchodilation : increases
26) A decrease in the affinity of hemoglobin for carbon dioxide caused by the binding of oxygen to 26) hemoglobin is described by the A) carbamino effect. B) Bohr effect. C) respiratory quotient. D) Haldane effect. E) Henderson-Hasselbalch effect.
A) carbamino effect.
87) A change in the ratio of bicarbonate to carbon dioxide concentration in the blood will 87) A) change blood pH. B) change blood potassium concentration. C) change blood chloride concentration. D) cause a bronchodilation. E) cause a vasodilation of systemic arterioles.
A) change blood pH.
19) Hyperventilation will cause changes in PCO2 that are detected by the chemoreceptors which causes 19) a(n) A) decrease in breathing rate and depth of breathing. B) increase in breathing rate only. C) increase in depth of breathing only. D) increase in breathing rate and depth of breathing. E) decrease in breathing rate only.
A) decrease in breathing rate and depth of breathing.
1) What is a decrease in oxygen in the blood called? A) hypoxemia B) hypoxia C) anemia D) hypocapnia E) dysnemia
A) hypoxemia
7) What is a deficiency of oxygen in the tissues called? A) hypoxia B) hypocapnia C) apnea D) hypercapnia E) hypoxemia
A) hypoxia
85) The mixing of atmospheric air within the dead space of the conducting zone of the lung upon 85) inspiration results in a partial pressure of A) oxygen in the alveoli that is lower than atmospheric. B) carbon dioxide in the alveoli that is lower than atmospheric. C) nitrogen in the alveoli that is higher than atmospheric. D) water vapor in the alveoli that is lower than atmospheric. E) oxygen in the alveoli that is higher than atmospheric.
A) oxygen in the alveoli that is lower than atmospheric.
103) The ________ is the respiratory center that appears to facilitate the transition between inspiration 103) and expiration. A) pontine respiratory group B) ventral respiratory group C) central pattern generator D) medullary respiratory group E) dorsal respiratory group
A) pontine respiratory group
21) Which of the following does NOT contribute to the rapid movement of gases into and out of the 21) blood within the lungs? A) rapid blood flow B) concentration gradient C) permeability of the membrane D) thin membrane E) large surface area
A) rapid blood flow
41) The respiratory quotient is calculated as the 41) A) ratio of the volume of carbon dioxide produced per volume of oxygen consumed. B) sum of the volume of oxygen consumed and the volume of carbon dioxide produced. C) product of the volume of carbon dioxide consumed and the volume of oxygen produced. D) ratio of the volume of oxygen consumed per volume of carbon dioxide produced. E) product of the volume of oxygen consumed and the volume of carbon dioxide produced.
A) ratio of the volume of carbon dioxide produced per volume of oxygen consumed.
71) Movement of oxygen and carbon dioxide between alveoli and blood occurs by what process? 71) A) simple diffusion B) osmosis C) facilitated diffusion D) primary active transport E) secondary active transport
A) simple diffusion
31) The primary effect of increased PO2 in the lungs is to cause ________ which ________ the 31) ventilation-perfusion ratio back to a normal level. A) vasodilation : decreases B) vasoconstriction : increases C) bronchodilation : increases D) bronchoconstriction : decreases E) vasoconstriction : decreases
A) vasodilation : decreases
55) What percentage of oxygen is transported in the plasma? A) 98.5% B) 1.5% C) 86% D) 75% E) 5%
B) 1.5%
101) Assuming resting conditions at sea level, what is the partial pressure of oxygen in systemic 101) arteries? A) 46 mm Hg B) 100 mm Hg C) 40 mm Hg D) 80 mm Hg E) 160 mm Hg
B) 100 mm Hg
93) Assuming resting conditions at sea level, what is the partial pressure of oxygen in alveoli? 93) A) 46 mm Hg B) 100 mm Hg C) 40 mm Hg D) 80 mm Hg E) 160 mm Hg
B) 100 mm Hg
57) Assuming resting conditions at sea level, what is the partial pressure of carbon dioxide in alveoli? 57) A) 160 mm Hg B) 40 mm Hg C) 46 mm Hg D) 80 mm Hg E) 100 mm Hg
B) 40 mm Hg
64) Assuming resting conditions at sea level, what is the partial pressure of oxygen in pulmonary 64) arteries? A) 100 mm Hg B) 40 mm Hg C) 80 mm Hg D) 160 mm Hg E) 46 mm Hg
B) 40 mm Hg
13) In the pulmonary arteries, the partial pressure of oxygen is approximately ________, and 13) hemoglobin is approximately ________ saturated with oxygen. A) 80 mm Hg : 90% B) 40 mm Hg : 75% C) 60 mm Hg : 80% D) 25 mm Hg : 50% E) 100 mm Hg : 98%
B) 40 mm Hg : 75%
8) What is the normal pH range for blood? 8) A) 7-10 B) 7.38-7.42 C) 7 D) 7.35-7.45 E) 1-14
B) 7.38-7.42
18) What percentage of oxygen is transported by hemoglobin? 18) A) 75% B) 98.5% C) 86% D) 5% E) 1.5%
B) 98.5%
9) Which statement best describes why oxygen is unloaded in tissue that is highly active? 9) A) As temperature increases, the Bohr effect causes hemoglobin to release oxygen. B) As temperature increases due to increased metabolism, the affinity of hemoglobin for oxygen is decreased. C) Highly active tissues produce more carbon dioxide, which competes for the heme groups in hemoglobin, thereby displacing oxygen. D) As temperature increases, the carbamino effect causes hemoglobin to release oxygen. E) As temperature increases, the affinity for oxygen to hemoglobin increases, allowing more oxygen to be carried to the tissues.
B) As temperature increases due to increased metabolism, the affinity of hemoglobin for oxygen is decreased.
97) Which statement best describes the effect on the body due to pH changes either above or below the 97) normal range? A) Changes in pH can only lower pH causing acidosis, meaning organs deteriorate due to high levels of acid. B) Changes in pH can denature proteins that serve as enzymes and receptors throughout the body, resulting in widespread effects on the body. C) Changes in pH out of the normal range are normal and will not have any detrimental effects on the body. D) pH ranges vary throughout the body; therefore, blood pH has no detrimental effects on the body as it changes pH. E) Changes in pH destroy the nephrons of the kidney, making kidney failure is inevitable.
B) Changes in pH can denature proteins that serve as enzymes and receptors throughout the body, resulting in widespread effects on the body.
22) The relationship between the concentration of a gas in solution and the partial pressure of that gas 22) can be described by A) Dalton's law. B) Henry's law. C) Poiseuille's law. D) Fick's law. E) Boyle's law.
B) Henry's law.
48) Which of the following can increase the concentration of a particular gas in a solution? 48) A) Decrease the concentration of other gases in the solution. B) Increase the partial pressure of that gas exposed to the solution. C) Increase the volume of the gas only. D) Increase the volume of the solution only. E) Increase the volume of the container containing the gas and solution.
B) Increase the partial pressure of that gas exposed to the solution.
72) When the blood becomes ________, it can lead to a depression in the activity of the central nervous 72) system. A) pH 7.4 B) acidic C) hypoxic D) alkaline E) hypocapnic
B) acidic
69) During active breathing, bursts of action potentials are observed to occur 69) A) synchronously in the inspiratory and expiratory motor neurons. B) asynchronously in the inspiratory and expiratory motor neurons. C) exclusively in the inspiratory motor neurons. D) exclusively in the expiratory motor neurons. E) simultaneously in the inspiratory and expiratory motor neurons.
B) asynchronously in the inspiratory and expiratory motor neurons.
58) A decrease in the affinity of hemoglobin for oxygen caused by the binding of carbon dioxide to 58) hemoglobin is described by the A) respiratory quotient. B) carbamino effect. C) Bohr effect. D) Henderson-Hasselbalch effect. E) Haldane effect.
B) carbamino effect.
29) Hypoventilation would lead to a(n) ________ within the systemic arteries. 29) A) selective decrease in PO2 B) decrease in PO2 and increase in PCO2 C) increase in PO2 and decrease in PCO2 D) selective increase in PO2 E) selective decrease in PCO2
B) decrease in PO2 and increase in PCO2
51) What is labored or difficult breathing called? 51) A) hyperpnea B) dyspnea C) hypopnea D) apnea E) eupnea
B) dyspnea
105) Within an erythrocyte, the conversion of CÓ to bicarbonate is prevented from reaching 105) equilibrium by the A) temperature of the body. B) efflux of bicarbonate from the erythrocyte via the chloride shift. C) presence of hydrogen ions. D) absence of a nucleus. E) presence of oxygen.
B) efflux of bicarbonate from the erythrocyte via the chloride shift.
20) Which of the following causes a decrease in the PO2 of air as it enters the conducting zone of the 20) lungs? A) the increasing PCO2 B) humidifying the air C) the consumption of oxygen D) decreasing alveolar PO2 E) warming of the air
B) humidifying the air
91) The carbamino effect describes a change in the conformation of hemoglobin that is induced by a(n) 91) A) increase in pH. B) increase in CÓ. C) decrease in pH. D) decrease in temperature. E) increase in temperature.
B) increase in CO2.
68) Hyperventilation would lead to a(n) ________ within the systemic arteries. 68) A) selective decrease in PCO2 B) increase in PO2 and decrease in PCO2 C) selective decrease in PO2 D) decrease in PO2 and increase in PCO2 E) selective increase in PO2
B) increase in PO2 and decrease in PCO2
98) What is the most common cause of pulmonary edema? 98) A) kidney failure B) left heart failure C) blood clot D) collapsed lung E) right heart failure
B) left heart failure
66) Pulmonary edema describes a condition where the uptake of oxygen and unloading of carbon 66) dioxide is reduced as a consequence of a(n) A) decrease in the partial pressure of carbon dioxide in the alveolus. B) thickening of the diffusion barrier by fluid accumulation in the alveoli. C) decrease in the partial pressure of oxygen in the alveolus. D) increase in the partial pressure of oxygen in the blood. E) thickening of the diffusion barrier by fluid accumulation in the pulmonary blood.
B) thickening of the diffusion barrier by fluid accumulation in the alveoli.
38) A decrease in PCO2 within the lung will result in a ________ in the pulmonary vasculature and a 38) ________ in the bronchioles. A) vasodilation : weak bronchodilation B) weak vasodilation : bronchoconstriction C) vasoconstriction : lack of change D) lack of change : weak bronchoconstriction E) weak vasoconstriction : bronchodilation
B) weak vasodilation : bronchoconstriction
30) In the systemic arteries, the partial pressure of oxygen is approximately ________, and hemoglobin 30) is approximately ________ saturated with oxygen. A) 40 mm Hg : 50% B) 100 mm Hg : 75% C) 100mmHg:98% D) 60 mm Hg : 50% E) 40 mm Hg : 75%
C) 100mmHg:98%
24) At sea level the air pressure which equals 1 atmosphere is 24) A) 600 mm Hg. B) 500 mm Hg. C) 760 mm Hg. D) 100 mm Hg. E) 150 mm Hg
C) 760 mm Hg.
37) A decrease in the affinity of hemoglobin for oxygen caused by the binding of a hydrogen ion to 37) hemoglobin is described by the A) Henderson-Hasselbalch effect. B) respiratory quotient. C) Bohr effect. D) Haldane effect. E) carbamino effect.
C) Bohr effect.
42) Which of the following best describes a chemoreceptor response to PO2? 42) A) Peripheral chemoreceptors respond only indirectly to PO2. B) Peripheral chemoreceptors respond to small changes in PO2. C) Central chemoreceptors do not respond to changes in PO2. D) Peripheral chemoreceptors respond to oxyhemoglobin. E) Central chemoreceptors respond to only large decreases in PO2.
C) Central chemoreceptors do not respond to changes in PO2.
88) Which of the following statements is FALSE regarding a rightward shift in the hemoglobin-oxygen 88) dissociation curve? A) Hemoglobin unloading of oxygen is increased. B) A rightward shift usually occurs in active tissue. C) It can be caused by a decrease in 2,3-BPG. D) Oxygen loading onto hemoglobin is decreased. E) Affinity for oxygen is decreased.
C) It can be caused by a decrease in 2,3-BPG.
63) What is the primary driving force for the binding of oxygen to hemoglobin? A) temperature B) PCO2 C) PO2 D) pH E) 2,3-bisphosphoglycerate (2,3-BPG)
C) PO2
34) At equilibrium, which of the following statements is TRUE when helium and nitrogen are present 34) in a gas at equal partial pressures over water? A) The partial pressure of nitrogen is greater than the partial pressure of helium. B) The concentrations of helium and nitrogen in the gas are equal. C) The partial pressures of helium and nitrogen in the water are equal. D) The concentrations of helium and nitrogen in the water are equal. E) The concentrations of helium and nitrogen in both the water and gas are equal.
C) The partial pressures of helium and nitrogen in the water are equal.
74) Central chemoreceptors are neurons in the medulla that respond directly to changes in 74) A) blood pH. B) cerebrospinal fluid PO2. C) cerebrospinal fluid pH. D) blood pH and PO2. E) cerebrospinal fluid PO2 and pH.
C) cerebrospinal fluid pH.
17) The venous blood in the right ventricle is referred to as "mixed" because the blood that enters the 17) heart A) has a high PCO2. B) contains a mixture of oxygen and carbon dioxide. C) comes from tissue with differing metabolic activities. D) has a low PO2. E) is drained from the body.
C) comes from tissue with differing metabolic activities.
3) During quiet breathing, a person's breathing cycle consists of A) contraction and relaxation of inspiratory and expiratory muscles. B) contraction of inspiratory muscles. C) contraction and relaxation of inspiratory muscles. D) contraction of inspiratory muscles and relaxation of expiratory muscles. E) contraction of expiratory muscles.
C) contraction and relaxation of inspiratory muscles.
94) As humidity increases, the partial pressure of oxygen in air 94) A) increases as the total pressure of air remains the same. B) increases as the total pressure of air increases. C) decreases as the total pressure of air remains the same. D) decreases as the total pressure of air increases. E) does not change.
C) decreases as the total pressure of air remains the same.
59) Where in blood does the conversion of CO2 to bicarbonate occur? 59) A) capillary endothelial cells B) plasma C) erythrocytes D) platelets E) leukocytes
C) erythrocytes
83) Each ________ on the hemoglobin subunit is capable of binding an oxygen molecule, thereby 83) allowing ________ oxygen to bind with one hemoglobin molecule. A) free iron : one B) globin : three C) heme : four D) globin : four E) heme : three
C) heme : four
77) The buffering capacity of hemoglobin is directly related to its ability to bind with 77) A) carbon monoxide. B) carbon dioxide. C) hydrogen ions. D) nitrogen. E) oxygen.
C) hydrogen ions.
6) What is a decrease in carbon dioxide within the blood called? 6) A) hypercapnia B) hypoxia C) hypocapnia D) hypoxemia E) hyperpnea
C) hypocapnia
25) A local bronchodilation within the alveolus will result in a(n) ________ in the ventilation-perfusion 25) ratio in that region. A vasoconstriction of pulmonary arteriole diameter will result in a(n) ________ in the ventilation-perfusion ratio in that region. A) increase : decrease B) decrease : decrease C) increase : increase D) decrease : increase E) lack of change : increase
C) increase : increase
70) Coughing is initiated by ________ located in the ________. 70) A) stretch receptor : trachea B) chemoreceptors : trachea C) irritant receptors : trachea D) irritant receptors : nose and pharynx E) chemoreceptors : nose and pharynx
C) irritant receptors : trachea
36) The presence of bicarbonate ions in the blood has an important direct effect, aside from the 36) transport of CO2, that involves A) altering the affinity of hemoglobin for oxygen. B) altering the activity of carbonic anhydrase. C) maintaining acid-base balance. D) altering the activity of several receptors. E) stimulating the proliferation of alveolar epithelial cells.
C) maintaining acid-base balance.
34) At equilibrium, which of the following statements is TRUE when helium and nitrogen are present 34) in a gas at equal partial pressures over water? A) The partial pressure of nitrogen is greater than the partial pressure of helium. B) The concentrations of helium and nitrogen in the gas are equal. C) The partial pressures of helium and nitrogen in the water are equal. D) The concentrations of helium and nitrogen in the water are equal. E) The concentrations of helium and nitrogen in both the water and gas are equal. Answer: C Explanation: A) B) C) D) E)
C) partial pressure.
12) Oxygenated blood is found in which of the following? 12) A) right atrium only B) pulmonary artery only C) pulmonary vein only D) both the right atrium and pulmonary artery E) both the right atrium and pulmonary vein
C) pulmonary vein only
32) What is rapid shallow breathing called? 32) A) apnea B) dyspnea C) tachypnea D) eupnea E) hyperpnea
C) tachypnea
73) Assuming resting conditions at sea level, what is the partial pressure of oxygen in pulmonary 73) veins? A) 40 mm Hg B) 160 mm Hg C) 80 mm Hg D) 100 mm Hg E) 46 mm Hg
D) 100 mm Hg
81) Assuming resting conditions at sea level, what is the partial pressure of oxygen in air? 81) A) 80 mm Hg B) 46 mm Hg C) 100 mm Hg D) 160 mm Hg E) 40 mm Hg
D) 160 mm Hg
62) What percentage of air is oxygen? A) 79% B) 12% C) 6% D) 21% E) < 1%
D) 21%
92) What is the partial pressure of oxygen in a gas mixture that is 40% oxygen, 40% argon, and 20% 92) helium, when the total pressure of the gas is 1000 mm Hg? A) 600 mm Hg B) 100 mm Hg C) 200 mm Hg D) 400 mm Hg E) 333 mm Hg
D) 400 mm Hg
86) As it leaves the lung in the pulmonary vein, blood is ________ saturated with oxygen. 86) A) 75% B) 90% C) 100% (completely) D) 98% E) 108% (supersaturated)
D) 98%
27) What is the primary mechanism of carbon dioxide transport in blood? 27) A) as bicarbonate dissolved in the red blood cells B) bound to hemoglobin C) dissolved in the plasma D) as bicarbonate dissolved in the plasma E) dissolved in the red blood cells
D) as bicarbonate dissolved in the plasma
39) Which of the following will cause a shift in the hemoglobin-oxygen dissociation curve to the right? 39) A) increase in temperature only B) increase in plasma pH only C) increase in 2,3-BPG (2,3-bisphosphoglycerate) only D) both an increase in temperature and an increase in 2,3-BPG E) both an increase in temperature and an increase in plasma pH
D) both an increase in temperature and an increase in 2,3-BPG
80) Which of the following will increase the loading of oxygen onto the hemoglobin molecule within 80) the lungs? A) increased 2,3-bisphosphoglycerate (2,3-BPG) B) decreased pH C) increased body temperature D) decreased hydrogen ion concentration E) increased PCÓ
D) decreased hydrogen ion concentration
28) Chemoreceptors respond primarily to changes in PCO2 indirectly by its effect on 28) A) lactic acid concentration. B) hemoglobin concentration. C) 2,3-diphosphoglycerate (2,3-DPG) concentration. D) hydrogen ion concentration. E) PO2.
D) hydrogen ion concentration.
61) What is an increase in alveolar ventilation to match the demands of increased metabolic activity in 61) the cells called? A) hypoventilation B) hyperventilation C) dyspnea D) hyperpnea E) hypopnea
D) hyperpnea
82) Respiratory acidosis can occur during 82) A) hyperpnea. B) the Haldane effect. C) hypocapnia. D) hypoventilation. E) hyperventilation.
D) hypoventilation.
60) Respiratory acidosis will result from a(n) 60) A) decrease in blood CO2 concentration. B) increase in blood bicarbonate. C) increase in carbon monoxide. D) increase in blood CO2 concentration. E) decrease in blood bicarbonate.
D) increase in blood CO2 concentration.
67) In a mixture of gases, the driving force for the movement of an individual gas within that mixture 67) is ultimately the A) volume of the gas. B) solubility of the gas. C) fractional concentration of that gas. D) partial pressure of that gas. E) total pressure of the gases.
D) partial pressure of that gas.
75) Your patient is in the hospital due to left heart failure. In your observation, you notice that she has a 75) 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. A) myocardial infarction B) internal bleeding C) decompression sickness D) pulmonary edema E) prolapsed heart valve
D) pulmonary edema
16) Assuming resting conditions at sea level, what is the partial pressure of carbon dioxide in systemic 16) veins? A) 160 mm Hg B) 80 mm Hg C) 40 mm Hg D) 100 mm Hg E) 46 mm Hg
E) 46 mm Hg
46) Which statement best describes how people die of carbon monoxide poisoning? 46) A) Carbon monoxide causes the carbamino effect where carbon dioxide is stripped of an oxygen, producing carbon monoxide. B) Carbon monoxide is toxic because it readily picks up oxygen to produce carbon dioxide, causing acidosis and eventual death. C) 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. D) Carbon monoxide causes decompression sickness which can lead to death. E) Carbon monoxide is toxic because it binds more readily to hemoglobin than oxygen, thereby decreasing the oxygen carrying capacity of blood.
E) Carbon monoxide is toxic because it binds more readily to hemoglobin than oxygen, thereby decreasing the oxygen carrying capacity of blood.
90) Peripheral chemoreceptors are specialized cells in contact with arterial blood that respond directly 90) to changes in blood A) pH. B) PÓ. C) PCÓ. D) PCÓ and PÓ. E) PÓ, pH, and PCÓ.
E) PO2, pH, and PCO2.
79) The Haldane effect describes the increase in the affinity of hemoglobin for CÓ in the presence of a 79) lowered A) pH. B) PCÓ. C) concentration of bicarbonate (HCǑ-). D) temperature. E) PÓ.
E) PO2.
50) During intense exercise, the metabolic activity of muscle causes ________ in the partial pressure of 50) oxygen in the tissue, ________ the movement of oxygen into the tissue. A) an increase : reducing B) an increase : facilitating C) no change : facilitating D) a decrease : reducing E) a decrease : facilitating
E) a decrease : facilitating
35) What is the definition of anemia? 35) A) a decrease in PO2 B) a decrease in the affinity of hemoglobin for oxygen C) a decrease in hemoglobin D) an increase in PCO2 E) a decrease in the oxygen carrying capacity of the blood
E) a decrease in the oxygen carrying capacity of the blood
4) The hydrogen ions released by the dissociation of carbonic acid are buffered by their 4) A) transport into the erythrocyte as sodium ions move out. B) transport out of the erythrocyte as a sodium ion moves in. C) active transport out of the erythrocyte. D) binding to DNA within the nucleus. E) binding to hemoglobin.
E) binding to hemoglobin.
100) Which of the following nerves has activity during quiet inspiration? 100) A) phrenic nerve only B) internal intercostal nerve only C) external intercostal nerve only D) both the phrenic nerve and internal intercostal nerves E) both the phrenic nerve and external intercostal nerves
E) both the phrenic nerve and external intercostal nerves
15) Which of the following increases oxygen unloading from hemoglobin? 15) A) decreased temperature B) increased blood pH C) increased oxygen levels in the tissue D) decreased metabolism E) increased carbon dioxide in the tissue
E) increased carbon dioxide in the tissue
11) Which of the following will increase the unloading of oxygen within the tissue? 11) A) increased hydrogen ion concentration only B) increased PCO2 only C) increased body temperature only D) both increased hydrogen ion concentration and increased body temperature E) increased hydrogen ion concentration, increased body temperature, and increased PCO2
E) increased hydrogen ion concentration, increased body temperature, and increased PCO2
) Bicarbonate is an important buffer in blood and its concentration is regulated by the 1) A) liver. B) pancreas. C) lungs. D) heart. 2) E) kidneys.
E) kidneys.
96) What is the most abundant gas in the air that we breathe? 96) A) carbon dioxide B) hydrogen C) oxygen D) water vapor E) nitrogen
E) nitrogen
43) Mixed venous blood samples can be taken from which of the following blood vessels? 43) A) pulmonary vein B) inferior vena cava C) superior vena cava D) aorta E) pulmonary artery
E) pulmonary artery
14) A decrease in the affinity of oxygen for hemoglobin is reflected as a ________ shift in the 14) hemoglobin-oxygen dissociation curve, which would facilitate the ________ of oxygen. A) rightward : loading B) neutral : loading C) leftward : unloading D) leftward : loading E) rightward : unloading
E) rightward : unloading
