A. Mucus B. Cilia C. Macrophages in Alveoli D. Type-I Alveolar Epithelial Cell

28. Which of the followings is not involved in removing the dust particles brought into the respiratory system by the inhaled air? A. mucus B. cilia C. macrophages in alveoli D. type-I alveolar epithelial cell

29. In which portion of the respiratory tract, spasm of smooth muscles during asthma attack reduces ventilation. A. primary bronchi B. secondary bronchi C. tertiary bronchi D terminal bronchioles

30. Which of the followings happens during exercise? A. vasodilation of the involved muscles. B. vasodilation in intestines C. vasodilation in inactive muscles D. increased blood flow to all (inactive and active) skeletal muscles

31. Dead space in the respiratory system refers to ____. A. the place where there is no air flow. B. the place where there is no gas exchange between the blood and the air. C. the entire respiratory system from nose to alveoli

32. The respiratory membrane has the following features except____. A. being large (500-700 SF) B. being very thick C. containing the wall of alveoli D. separating blood from air

33. Which of the following events occur in right order during inspiration? A. volume change of the lungs  pressure change in the lungs  air flow into the lungs B. air flow into the lungs  volume change of the lungs  pressure change in the lungs C. pressure change in the lungs volume change of the lungs  air flow into the lungs

34. Contraction of the diaphragm ____. A. pushes itself up B. reduces all three dimensions of the thoracic cageC. occurs during expiration D. decreases intrapulmonary pressure.

35. Contraction of external intercostal muscles ____. A. occurs during inspiration B. occurs during expiration C. is not involved in respiration

36. If the pleural cavity leaks to atmosphere, what will happen? A. The thoracic cage cannot expand when the inspiratory muscles contract. B. The inspiratory muscles cannot contract. C. The affected lungs won’t expand with the thoracic cage during inspiration. 37. A premature infant that lacks surfactant has ___. A. difficulty in inspiration. B. difficulty in expiration. C. no difficulty in either inspiration or expiration

38. A decrease in the diameter of bronchioles mainly causes ___. A. an increase in elastic resistance. B. an increased resistance against expiration but not inspiration. C. an increased resistance against inspiration but not expiration. D. an increased resistance against both inspiration and expiration

39. Where in the central nervous system can a complete severing eliminate spontaneous respiration? A. between cerebral cortex and thalamus B. between thalamus and cerebellum C. between pons and medulla oblongata D. between medullar oblongata and spinal cord

40. After complete severing of which place in the central nervous system, the spontaneous respiration does not disappear but becomes less smooth? A. between cerebral cortex and thalamus B. between thalamus and cerebellum C. between pons and medulla oblongata D. between medullar oblongata and spinal cord 41. The primary inspiratory centers that generate respiration rhythms are influenced directly by input from all of the following except ____. A. hypothalamus B. motor cortex C. chemoreceptorsD. lungs

42. Immediately after entering high mountains, normal people have a decrease in their blood oxygen content, which is caused most likely by ___. A. a decreased share of oxygen in the mixed atmospheric air (example: decreased from 21% to 15% of total atmospheric air) B. a decreased total atmospheric pressure (from 760 mmHg to 600 mmHg) with no change in the share of oxygen as percent of the mixed air . C. decreased number of red blood cells D. decreased hemoglobin content

43. Patients with obstructive respiratory diseases have a decrease in their blood oxygen content, most likely due to ____. A. a decreased share of oxygen in the mixed alveolar air (example: decreased from 13.6% to 10% of total alveolar air) B. a decreased total atmospheric pressure (from 760 mmHg to 600 mmHg) with no change in the share of oxygen as percent of the mixed air . C. decreased number of red blood cells D. decreased hemoglobin content

44. Patients with pneumonia may have a decreased gas exchange capacity most likely due to ____. A. a decreased share of oxygen in the mixed alveolar air (example: decreased from 13.6% to 10%) B. the thickening of the respiratory membrane C. decreased number of red blood cells D. decreased hemoglobin content

45. Based on the concept of ventilation-perfusion coupling, which of the following will increase the alveolar gas exchange to the greatest extent? (assuming the original ventilation-perfusion ratio is 0.8) A. increase air flow by 50% with no change in blood flow B. increase blood flow by 50% with no change in air flow C. increase air flow and blood flow both by 30%

46. A decrease in the Po2 in the environment around red blood cells is expected to cause ___. A. dissociation of oxygen from red blood cells. B. an increased association of oxygen with red blood cells C. no change in the association of oxygen with red blood cells

47. If you separate the formed elements of the blood from plasma by centrifugation, you will find ____. A. more oxygen in the plasma B. more oxygen in the formed elements C. equal amount of oxygen in the plasma and the formed elements. 48. Extensive vasodilation throughout the systemic circulation is expected to cause ___. A. decrease in arterial pressure B. increase in arterial pressure C. no change in arterial pressure

49. In which of the following places, PCO2 (partial pressure of carbon dioxide) is the highest? A. alveolar airB. blood in the systemic arteries C. blood in the arterial end of systemic capillaries D. blood in the systemic veins

50. Which of the following statements about oxygen is FALSE ? A. More ATP is generated from glucose in the presence of oxygen than without oxygen. B. Oxygen is a nutrient. C. Oxygen cannot be produced by human being. D. Exposure to excessive oxygen will not cause any damage to tissue cells.

28D 29D 30A 31B 32B 33A 34D 35A 36C 37A 38D 39D 40C

41B 42B43A 44B 45C 46A 47B 48A 49D 50D