16. Which of the following statements about pulmonary ventilation is NOT true?

A. Airflow in and out of the lungs is driven by the pressure difference between atmosphere and the lungs.

  1. Air moves into the lungs during inspiration because the volume of the lungs is increased, thus dropping intrapulmonary pressure.
  2. The Lungs can expand by themselves due to contraction of muscles in alveolar wall.
  3. The lungs move passively along the thoracic cage as the results of respiratory muscle contraction and relaxation.

17. During forced respiration, which of the following muscles is contracting.

A.the diaphragm
B.the external intercostal muscles
C.the abdominal muscles

18. Which of the following statements about pleural cavity is true?

D.The closed and air-proof pleural cavity is needed to prevent the lungs from collapse.
E.The pleural cavity is formed by visceral pleura and parietal pleura.
F.The pleural cavity containing pleural fluid that serves to reduce friction during chest expansion.
G.All of the above

19. Alveolar surface tension ____.

  1. tends to prevent a collapse of the alveoli.
  2. is generated by a thin liquid film over the surface of alveolar epithelium.
  3. is enhanced by surfactant, which is secreted by type II alveolar epithelial cells.

20. Which of the following is a resistance against inspiration?

  1. alveolar surface tension
  2. elastic resistance
  3. airway resistance

D.all of the above

21. Which of the following is a resistance against expiration?

  1. alveolar surface tension
  2. elastic resistance

C.airway resistance

22. In the respiratory system, dead space refers to ___.

  1. a space that contains dead cells.
  2. a space with a dead end.

C.a space where no gas exchange occurs between inhaled air and the blood in the lungs

23. The amount of air inhaled at resting breathing is called ____.

A.inspiratory reserve volume
B.tidal volume
C.expiratory reserve volume,
D.residual volume
E.respiratory capacities

24. The basic inspiratory and expiratory center is located in ___.

  1. hypothalamus

B.medulla oblongata

  1. pons
  2. motor cortex
  3. spinal cord

25. Respiration is under voluntary control by ___ to some extent.

  1. hypothalamus

B.medulla oblongata

  1. pons

D.motor cortex

  1. spinal cord

26. Under which of the following conditions, respiration is enhanced via chemoreceptor-initiated reflexes?

  1. low CO2 in the blood
  2. high oxygen in the blood

C.low blood pH

27. Chemoreceptors are located in ___.

A.aortic body

  1. trachea
  2. bronchioles
  3. lungs
  4. nose

28. Tissue cells can get O2 because ____.

  1. fresh air is inhaled into the lungs
  2. the respiratory membrane is permeable to O2
  3. the blood transport O2 to tissue cells
  4. cell membranes are permeable to O2
E.all of the above

29. Factors that determine the efficiency of alveolar gas exchange include

A.all of the following
  1. solubility of the gases in the blood
  2. thickness of the respiratory membrane
  3. respiratory membrane area
  4. ratio of ventilation-perfusion

30. What percentage of O2 in the blood is carried by hemoglobin?

A.98.5%

  1. 75%
  2. 50%
  3. 5%

31. Association of O2 with hemoglobin is affected by ___.

  1. partial pressure of O2
  2. partial pressure of CO2
  3. pH
D.all of the above

KEY

16C 17C 18D 19B 20D 21C 22C 23B 24B 25D 26C 27A 28E 29A 30A 31D