sign in sign up
<<
Home , Chloride shift, Dead space (physiology), Oxygen toxicity

RESPIRATORY

1. The anatomic a. Varies with b. Is typically 150mL c. Will increase in C.O.P.D d. Is alveolar minus the pathological dead space e. All of the above

2. With regards to pulmonary a. Transfer of nitrous oxide is limited b. Transfer of is typically limited c. At altitude the profound systemic hypoxaemia favours oxygen diffusion d. The diffusion rate for CO2 is double that of oxygen e. Diffusion is inversely proportional to the partial gradiant

3. With regard to the distribution of pulmonary blood flow a. Typically there is a zone at the apex that is not perfused b. The mean pulmonary arterial pressure is 8mmHg c. In some areas flow is determined by the arterial/alveolar pressure difference d. leads to pulmonary vasodilation e. The net balance of Starling act to keep the alveoli dry

4. At a barometric pressure of 500mmHg and 30% oxygen by a fixed performance system, the alveolar oxygen tension can be calculated as a. 86mmHg b. 95mmHg c. 98mmHg d. 136mmHg e. not enough information

5. The haemoglobin oxygen dissociation curve moves up and to the left with a. Increased hydrogen ion b. c. Increased 2,3 DPG d. Hypercarbia e. All of the above

6. The refers to a. The increased capacity for deoxygenated blood to carry CO2 b. The dissociation constant for the buffer system c. The that occurs to maintain electrical neutrality d. The carriage of dissolved CO2 according to Henry’s law e. The shape of the CO2 dissociation curve

7. La Place’s law a. Explains the observed of the chest b. Determines the change in volume per unit change in pressure c. Tells us the pressure is inversely related to tension d. Explains the tendency of small alveoli to collapse e. All of the above

8. In the medullary respond to a. Oxygen tension b. Hydrogen ion concentration c. CO2 tension + d. H concentration and CO2 tension + e. H concentration and oxygen and CO2 tension

9. compliance of the is reduced by all of the following except a. emphysema b. alveolar oedema c. fibrosis d. consolidation e. high expanding

10. Pulmonary vascular resistance a. Increases as venous pressure rises b. Is increased in both very low and high c. Is decreased by histamine d. Is increased by muscular pulmonary arterioles which regulate blood flow to various regions of the e. Increases with recruitment

11. Regarding pulmonary blood flow a. Low blood pH causes vasodilation b. At high altitude, generalized vasodilation causes a rise in pulmonary arterial pressure c. Vasoconstriction may occur when the alveolar pO2 is reduced below 55mmHg d. Inhaled nitrous oxide reduces pulmonary vasoconstriction e. Endothelins are potent vasodilatory peptides

12. causes of hypoxic hypoxia include all of the following except a. pulmonary shunting b. morphine c. pulmonary fibrosis d. fatigue e. congestive heart failure

13. Regarding buffers of the body a. Initial correction of pH disturbance is best achieved by the kidneys b. The phosphate buffer system is the predominant buffer in the blood c. Bones contribute to the buffer system by taking up HCO3 d. Hb is am important buffer of the blood e. All of the above are correct

14. Regarding ventilation/perfusion differences in the lungs a. In healthy individuals, anatomical dead space is less than physiological dead space b. The relative change in blood flow from apex to base is less than relative change in ventilation c. V/Q differences are due to gravity d. V/Q ratio is low at the bases e. All of the above

15. a. is normally 100mL/cm water b. falls if the lung remains unventilated for long periods c. rises if the pulmonary venous pressure is increased d. falls as the lung ages e. is the area under the pressure volume curve

16. work of the lung in breathing a. is increased with larger tidal volumes b. is increased with higher flow rates c. in inspiration need to overcome elastic forces and viscous resistance d. in expiration need to overcome airway and resistance e. all of the above

17. The most important short term response to high altitude is a. b. Polycythaemia c. Chronic mountain sickness d. Acidosis e. Decreased EPO release

18. Regarding the a. It gives the value of alveolar pO2 in a given patient b. R denotes the c. At sea level, pIO2 = 690mmHg x 0.21 of humidified air d. At high altitude, paCO2can be less than 35mmHg e. The alveolar gas equation is only applicable at sea level

19. In CO2 transport a. The HCO3 content of venous blood is reduced compared to arterial blood b. The osmolarity of RBCs in venous blood is increased compared to arterial blood c. The haematocrit of venous blood is 3% less than arterial blood d. The of CO2 in blood is less than O2 e. CO2 does not react with plasma proteins

20. With regard to the neural control of a. There are 3 neural mechanisms regulating respiration b. The dorsal group of respiratory centre has excitatory neurons c. The ventral group of respiratory centre is located in the d. The main respiratory control centre is located in the pons e. Voluntary control system is located in the cerebral cortex

21. a. Is produced by class II pneumocytes b. Is increased in smokers c. Helps keep the alveoli moist d. Decreases alveolar stability in preterm babies e. Maturation is impaired by glucocorticoids

22. Regarding the O2 dissociation curve a. Each gram of pure Hb can bind 1 mol of O2 b. 2,3 DPG levels fall at high altitude c. an increase in the affinity of Hb for O2 in an acid environment is called the d. a right shift implies a lower pO2 is required for O2 binding e. the p50 is an index of the affinity of Hb for O2

23. for the chemical control of respiration a. the carotid bodies respond to changes in pH, pCO2 and O2 b. the aortic bodies respond to changes in pH, pCO2 and O2 c. pO2 is only detected by d. severe hypoxia strongly stimulates central chemoreceptors e. the central chemoreceptors respond to changes in plasma pH

24. With respect to lung volumes a. FRC can be measured with a spirometer b. He dilution measures the total volume of gas in the lung, including any trapped behind closed airways c. The volume of gas left in the lungs after a maximal expiration is the functional residual volume d. is the volume exhaled when a maximal inspiration is followed by a maximal expiration e. TLC is the volume of the lung available to partake in gas exchange

25. Surfactant a. Increases b. Surface tension is proportional to their concentration c. Is produced by type I alveolar cells d. Is increased in cigarette smoking e. Prevents pulmonary oedema

26. The expected paO2 in mmHg of a person breathing 28% oxygen who has a paCO2 of 50 is a. 88 b. 118 c. 138 d. 150 e. 158

27. Haemoglobin dissociation curve shifts a. To the right with CO b. To the left with a rise in c. To the left with a rise in pH d. To the right with a decrease in 2,3 DPG e. To the left with anaemia

28. In CO2 transport a. There is slightly more in dissolved in the blood than oxygen b. Venous blood can carry more CO2 than arterial blood c. Chloride shift allows CO2 to dissociate d. There is equal amounts of CO2 transported as dissolved CO2 and carbamino compounds e. 2,3 DPG concentration in RBC will alter the cells ability to catalyse CO2

29. With respect to gas transport in the blood a. Arterial pO2 measures the amount of oxygen bound to haemoglobin b. Normal arterial blood with a pO2 of 100mHg contains 3mL of dissolved oxygen per litre c. Haldane effect refers to the shift of Chloride ions into the RBC to maintain electrical neutrality after carbon dioxide diffuses out of cells d. The great bulk of carbon dioxide in blood is found as dissolved carbon dioxide and carbamino compounds e. Oxygen capacity is the total amount of oxygen that can be carried in 100mL of blood

30. In regional ventilation and perfusion of the lung a. Upper regions of the lung ventilate better than the lower regions b. When supine the apical and basal ventilation is equal c. V/Q ratio increases down the lung d. The highest alveolar pO2 is at the base of the lung e. Blood flow is uniform throughout the normal lung

31. The main respiratory control neurons a. Send out regular bursts of impulses to expiratory muscles during quiet respiration b. Are unaffected by stimulation of pain receptors c. Are located in the pons d. Send out regular bursts of impulses to inspiratory muscles during quiet respiration e. Are unaffected by impulses from the cerebral cortex

32. With respect to dead space a. Dead space volume is equal to he person’s in kg b. For a constant minute ventilation, alveolar ventilation is decreased as respiratory rate increases c. Anatomic dead space is less than physiological dead space in healthy persons d. Physiological dead space is measured by analysis of single breath curves e. Total dead space equals physiological dead space + anatomic dead space

33. All of the following are effects of hypoxia except a. Increased EPO secretion b. Increase in respiratory minute volume c. Increase sensitivity to pCO2 d. Increased HR e. Pulmonary vasodilation

34. Ficks law of diffusion is dependent on all except a. Thickness of membrane barrier b. Solubility of the gas c. The molecular weight of the gas d. The posture of the subject e. The area of the membrane

35. With regards to the normal alveolus a. Surfactant is produced by type I pneumocytes b. Alveolar size has little effect on the surface tension c. Surfactant is composed of hydrophilic molecules d. Large alveoli have a tendency to collapse into smaller ones e. Surrounding tissues exert a preventing alveolar collapse

36. On climbing Everest a. EPO secretion rises after 2-3 days b. Nifedipine alleviates the symptoms of mountain sickness c. Alveolar pCO2 levels rise d. pCO2 levels fall because of decreased oxygen content of the air e. initially the oxygen-Hb dissociation curve shifts to the left

37. Regarding CO2 transport in the blood a. 50% is in the dissolved form b. the Haldane effect is the fact that oxygenation of the blood increases its ability to carry CO2 c. ionic dissociation of carbonic acid requires the presence of carbonic anydrase to be a fast process d. an increase in pCO2 in blood shifts the oxygen dissociation curve to the left e. approximately 30% of the venous arterial difference is attributable to carbamino compounds

38. The alveolar gas equation a. Is also known as the Bohr’s equation b. Can be used to calculate anatomical dead space c. Is influenced by diet d. Is independent of PiO2 e. Requires sampling of gas to determine PACO2

39. Regarding ventilation during exercise a. Pulmonary blood flow is increased from 5.5L/min – 55L/min b. Abrupt increase in ventilation at onset of exercise is due to increased respiratory rate c. Increases in ventilation are proportional to increased CO2 production d. CO2 excretion increases from 200mL/min up to 8000mL/min e. There is a fall in blood pH during moderate exercise

40. Oxygen transport a. The oxygen dissociation curve shifts left with a fall in pH b. More oxygen is supplied to tissues by a fall in 2,3 DPG levels c. 2,3 DPG levels are increased by ascent to 7000m d. 2,3 DPG levels in stored blood increase e. oxygen dissociation curve shifts right with a drop in temperature

41. The following are true regarding lung volumes and compliance except a. Compliance decreases in obstructive lung disease b. FEV1/FVC ration increases in obstructive lung disease c. FRC is the sum of ERV and RV d. The change in lung volume per unit change in airway pressure is the compliance of the lung e. Vital capacity is the largest amount of air that can be expired after a maximal inspiratory effort

42. With regards to ventilation a. The autonomic control centre is located in the midbrain b. Brainstem respiratory neurons only discharge during inspiration c. Arterial pO2 must be below 80mmHg to produce increased discharge from peripheral d. Medullary chemoreceptors monitor O2 in the CSF e. In metabolic alkalosis ventilation is depressed

43. Which one of the following definitions is incorrect a. The respiratory minute volume equals the amount of air inspired per minute b. Residual volume is the air left in the lungs after a maximal expiratory effort c. Vital capacity is the maximal amount of air that can be expired after a normal inspiration d. Physiological dead space is the amount of air not equilibrating with blood e. Compliance is the change in lung volume per unit change in

44. Which one of the following is activated in the lung a. Renin b. Angiotensin c. Kallikrein d. Bradykinin e. Prostaglandins

45. The oxygen Hb dissocation curve a. The p50 is roughly 83.5 b. Oxygenation status of haemoglobin has no effect c. In the low part of the curve, large amounts of oxygen is liberated to the tissues for small decreases in the O2 d. In the flat part of the curve, there is large changes in the saturation for small changes in pO2 e. A fall in pH shifts the curve to the left

46. which one of the following is false a. medullary chemoreceptors monitor the CO2 concentrations of the CSF b. HCO3 penetrate the BBB slowly c. E neurons in the brain stem usually only become active when ventilation is increased d. In metabolic acidosis CO2 response curves for fixed values of alveolar CO2 are shifted to the left e. Type I cells in the carotid bodies are not stimulated by hypoxia caused by CO poisoning

47. In a. A person needs to breathe higher concentrations of oxygen b. There is an increase in barometric pressure of 1 atm for every 15m of water c. Nitrogen acts as an inert gas d. Normal V/Q differences in the lung are exaggerated e. sickness is caused by oxygen

48. Substances metabolized by the lung include all except a. Serotonin b. NA c. ACh d. Glutamic acid e. Bradykinin

49. Substances synthesised by the lung include all of the following except a. Arachidonic acid b. Histamine c. Kallikrein d. Angiotensin I e. Surfactant

50. Pulmonary compliance a. Is decreased in emphysema b. Is defined as the change in pressure per unit change in volume c. Compliance is slightly greater when measured during deflation than when measured during inflation d. Is increased by pulmonary fibrosis e. Is independent of lung volume

51. With regard to pulmonary function a. is the volume of each maximal inspiration b. Residual volume is the volume remaining at the end of passive expiration c. Residual volume can be measured directly d. Vital capacity is equivalent to the total inspiratory reserve volume, tidal volume and expiratory reserve volume e. Tidal volume is measured by the single breath nitrogen technique

52. exposure to altitude a. shifts the O2-Hb dissociation curve to the right due to alkalosis b. is associated with an increase in RBC 2,3 DPG c. is associated with a decrease in p50 d. is associated with a e. has no effect on EPO secretion

53. with regard to high altitude a. there is a linear decrease in inspired oxygen pressure with increasing altitude b. the of water vapour in moist inspired air decreases with PIO2 c. at 19 200m, barometric pressure = 47mmHg, PIO2 is then 9mmHg d. at the peak of Everest, barometric pressure ~ 380mmHg, PIO2 is then approximately 70mmHg e. in permanent residents of the Andes, arterial and venous pO2 is half normal levels

54. A 28yo woman takes an OD of sedatives, causing her to hypoventilate. Her pCO2 is now 80mmHg, given that she is breathing room air, which of the following is likely to be correct a. PaO2 is ~ 70mmHg b. PaO2 is ~ 35mmHg c. SaO2 ~50% d. SaO2 ~80% e. SaO2 ~27%

55. substances cleared from the circulation by the lungs include all except a. angiotensin II b. serotonin c. Leukotrienes d. Bradykinin e. Prostaglandin

56. increased lung compliance is associated with a. increasing age b. increasing pulmonary venous pressure c. high expanding volumes d. interstitial fibrosis e. low lung volumes associated with hypoventilation

57. The following physiological events are in a random sequence, which is the usual sequence : (a) decreased CSF pH, (b) increased PaCO2, (c) increased CSF PCO2, (d) stimulation of medullary chemoreceptors, (e) increased PACO2 a. a b c d e b. d a c b e c. c d e b a d. e b c a d e. e c b d a

58. with regard to chemoreceptors, which is false a. the medullary chemoreceptors respond to a change in blood pCO2 b. the medullary chemoreceptors respond to blood H+ c. the predominant peripheral chemoreceptors are located in the carotid and aortic bodies d. the peripheral chemoreceptors respond to pO2 e. the peripheral chemoreceptors respond to blood H+

59. Functions of the lung include all of the following except a. Synthesis of phospholipids b. Synthesis of proteins c. Carbohydrate d. Inactivation of bradykinin e. Removal of DA

60. hypoxaemia is caused by all of the following except a. anaemia b. pulmonary fibrosis c. left to right shunt d. residing at high altitudes e. hypoventilation

61. regarding RQ, which is false a. ~ 0.82 b. RQ of brain tissue is approximately 1.0 c. RQ of carbohydrate = 1.0 d. RQ of carbohydrate > protein e. RQ of fat is 0.90

62. residual volume in a 70kg man most closely approximates a. 1L b. 2L c. 3L d. 4L e. 5L

63. regarding the lung volumes in a 70kg man a. ERV is > 1.0L b. IRV is < 3.0 L c. Residual volume = 1.2L

64. Regarding the of the lung a. Oxygen passage is diffusion limited b. Diffusion is directly proportional to the surface area of the alveolocapillary membrane and inversely proportional to the thickness

65. A permanent inhabitant at 4500m a. Has a high alveolar pO2 level b. Has a decreased 2,3 DPG c. Shows increased ventilation d. May have a normal HCO3 e. Is highly sensitized to the stimulatory effects of hypoxia

66. surfactant a. increases compliance b. is produced by type I pneumocytes c. is absorbed by type II pneumocytes

67. Given that the intrathoracic pressure changes from -5cmH2O to -10 with inspiration and a tidal volume of 500mL, what is the compliance of the lung a. 0.01 b. 0.1 c. 1.0 d. 10 e. 100

68. Pulmonary vascular resistance a. Increases as venous pressure rises b. Is increased at both high and low lung volumes c. Is decreased by histamine d. Increases with recruitment e. Is increased by muscular pulmonary arterioles which regulate flow to various regions of the lungs

69. What is the pO2 of alveolar air with a CO2 of 64 and a of 0.8 a. 35 b. 52 c. 69 d. 72 e. 80

70. What is the compliance of a lung if a balloon is blown up with 500mL of air with a pressure change from -5 to -10 a. 0.1 b. 1 c. 10 d. 100 e. 200

71. When walking at a steady pace, the increase in respiratory rate is due to a. Decreased pO2 b. Increased CO2 c. Increased pH d. Increased pH CSF e. None of the above

72. which of the following causes increased pulmonary vascular resistance a. altitude b. forced expiration

73. carotid body stimulation occurs with a. decreased BP b. decreased pO2 c. increased pO2 d. increased pH e. increased BP

ANSWERS 1. B 27. C 53. D 2. A 28. B 54. D 3. C 29. B 55. A 4. E 30. B 56. A 5. B 31. D 57. D 6. A 32. B 58. B 7. D 33. E 59. E 8. D 34. D 60. C 9. ?A 35. E 61. E 10. ? 36. E 62. A 11. D 37. E 63. C 12. E 38. C 64. B 13. D 39. D 65. D 14. D 40. C 66. A 15. B 41. B 67. B 16. E 42. E 68. B 17. A 43. C 69. D 18. D 44. B 70. A 19. B 45. C 71. E 20. E 46. A 72. A 21. A 47. D 73. B 22. E 48. D 23. A 49. D 24. D 50. C 25. E 51. D 26. C 52. B