Card Set Information

2014-07-20 20:50:43
A&P Test 5
West Ch 2
Show Answers:

  1. What is the maximal volume of all the airways in an adult? What structures does this include?
    • 5-6 liters
    • Nasopharynx, trachea, all the way to alveolar sacs
  2. What does a simple spirometer measure?
    • Volume of air inspired and expired.
    • Measures the CHANGE in lung volume
  3. What are the 4 standard lung volumes?
    • 1) tidal volume
    • 2) inspiratory reserve volume
    • 3) expiratory reserve volume
    • 4) residual volume
  4. What are the 4 standard lung capacities?
    • 1) inspiratory capacity: Vt + IRV
    • 2) functional residual capacity: ERV + RV
    • 3) total lung capacity: Vt + IRV + ERV + RV
    • 4) Vital capacity: Vt + IRV + ERV
  5. Define tidal volume
    Volume of air entering and leaving the nose or mouth per NORMAL BREATH
  6. What is the average adult Vt?
  7. Define inspiratory reserve volume
    ADDITIONAL volume of air a person can inhale ABOVE TIDAL VOLUME with maximal effort
  8. What is normal IRV?
    2.5-3 liters
  9. Define expiratory reserve volume
    Volume FORCEFULLY exhaled below tidal volume AFTER a quiet exhalation
  10. What is normal ERV?
    1.2-1.5 liters in normal healthy adult
  11. How is ERV mathematically determined?
    FRC - RV
  12. Define residual volume
    • Volume of air left in the lungs AFTER forced exhalation
    • Air that remains in lungs no matter what you do unless lungs collapse
  13. What is the normal RV?
    1.5 liters in healthy 70kg adult
  14. What conditions will result in abnormally elevated RV?
    Emphysema and COPD
  15. What are 2 functions of residual volume?
    • 1) prevents lungs from collapsing at very low lung volumes
    • 2) maintains patency of alveoli
  16. Can RV be measured with simple spirometry?
  17. Define total lung capacity
    Volume of air in the lungs after MAXIMAL INSPIRATORY EFFORT
  18. What is normal volume of TLC?
    6 liters
  19. How is TLC mathematically calculated?
  20. Define functional residual capacity
    Volume of gas remaining in lungs at the end of NORMAL TIDAL EXHALATION
  21. What is the normal volume of FRC?
    3 liters
  22. How is FRC mathematically calculated?
    ERV + RV
  23. What is the normal function of FRC?
    Prevents dramatic changes in alveolar and arterial oxygen with each breath
  24. What happens when FRC is significantly reduced?
    PO2 increases with inspiration and decreases with expiration
  25. How is denitrogenation related to FRC? How long should this take?
    • Denitrogenation is replacement of FRC nitrogen with oxygen
    • 5 minutes of denitrogenation is ideal; if not possible, have pt take 3-5 good, deep breaths
    • Must have good mask seal
  26. Define inspiratory capacity
    After QUIET inspiration, IC is MAXIMAL inhalation that one can still inspire
  27. What is normal volume of IC?
    3 liters
  28. How can IC be mathematically calculated?
    Vt + IRV
  29. What is the difference between IC and IRV?
    • IC begins at the end of normal EXPIRATION
    • IRV begins at the end of normal INSPIRATION
  30. Define vital capacity
    Volume of air that can be EXHALED with MAXIMUM effort after MAXIMUM inspiration
  31. What is the normal volume for VC?
    4.5 liters
  32. How can VC be mathematically calculated?
    • 1) TLC - RV
    • 2) Vt + IRV + ERV
  33. What does VC assess?
    • 1) strength of thoracic muscles
    • 2) pulmonary function
    • Can identify residual NMBD
  34. What conditions may increase VC?
    • 1) body size
    • 2) men
    • 3) physical conditioning
  35. What conditions may decrease VC?
    • 1) smoking
    • 2) obesity
    • 3) supine positioning
    • 4) poor posture: kyphoscoliosis or lordoscoliosis
  36. What is FEV1?
    • Forced expiratory volume in 1 second
    • Volume of air exhaled in 1 second after MAXIMAL inspiratory effort and rapid, as complete as possible, exhalation
  37. How is FEV1 related to VC?
    FEV1 is about 80% of VC
  38. What can simple spirometry measure?
    • 1) tidal volume
    • 2) IRV
    • 3) ERV
    • 4) IC
    • 5) VC
  39. What can simple spirometry not measure?
    RV and any volume that includes it (TLC and FRC)
  40. What are 2 types of gas-dilution techniques? What do they measure?
    • 1) helium-dilution
    • 2) nitrogen-washout
    • Measure RV, TLC, and FRC
  41. What does body plethysmography measure?
  42. How does body plethysmography work?
    • Application of Boyle's law
    • At a constant temperature, increased volume decreases pressure and vise versa
    • Patient placed in a closed chamber and makes inspiratory effort against CLOSED mouthpiece
    • This measures pressure and volume changes
    • Closed chamber resembles phone booth
  43. What changes in FRC can be expected when moving from standing to supine?
    Decreased FRC due to abdominal contents compressing diaphragm cephalad; decreased outward elastic recoil of the chest wall
  44. What changes in lung volume can be expected in restrictive lung disease?
    Everything is smaller, volumes and capacities
  45. What are some examples of restrictive lung disease?
    • 1) quadraplegic (can't expand/contract)
    • 2) ascites
    • 3) PULMONARY FIBROSIS - classic
    • 4) kyphoscoliosis
    • 5) lobectomy
    • 6) phrenic nerve injury
    • 7) rib fracture
    • 8) pregnancy
  46. What changes in lung volume can be expected in obstructive lung disease?
    • RV is much larger and capacities that include RV are increased:
    • TLC
    • FRC
  47. What is closing volume?
    • Volume where airway closure begins to occur
    • Bronchioles and alveoli
  48. What is closing capacity?
    Lung capacity where small airways begin to close
  49. How can closing capacity be mathematically calculated?
    CV + RV
  50. What is the normal relationship between FRC and CC?
    • Normal CC is less than FRC
    • Increases with age
  51. What is the relationship between FRC and CC at 44 years of age? At 66?
    • At 44, they are equal when supine
    • At 66, they are equal when standing
  52. What is the relationship between FRC and CC in neonates?
    CC > FRC
  53. What is the normal change in PaO2 with age? Why?
    Decreases with age due to increased CC
  54. What factors increase CC and CV?
    • 1) age
    • 2) smoking
    • 3) lung disease (asthma, emphysema, bronchitis)
    • 4) body position (supine>standing, long-term ICU or nursing home patient)
    • 5) decreased plasma oncotic pressure
    • With any of these conditions, airways tend to close at higher volumes (more easily)
  55. When lung volume is below CC, how is breathing affected?
    • Work of breathing increases due to shunt
    • Shunt = perfusion without gas exchange due to closed airways
  56. What will cause airways to remain collapsed when CC > RV?
    • 1) any pathological condition with lower tidal volume
    • 2) patient does not sign or yawn
  57. Alveoli in what region are most influenced by intrapleural pressure changes? Why?
    • Alveoli in bases are most influenced due to lower intrapleural pressure in upright position (less negative)
    • Apical alveoli are exposed to more negative intrapleural pressure that minimizes volumetric changes with respiration
  58. Alveoli in what region are most prone to collapsing during active expiration?
  59. What alveoli contribute most to V/Q mismatch?
  60. What is the relationship between weight and deadspace?
    Anatomical deadspace is approximately equal to the pt's weight in pounds
  61. How is anatomic dead space measured?
    Fowler's method
  62. What does Fowler's method do?
    Plots nitrogen concentration against expired volume
  63. What is physiologic dead space?
    Anatomical dead space + alveolar dead space
  64. What is the symbol for physiologic dead space?
  65. What is physiologic dead space in healthy people?
    • Anatomical dead space
    • There is no alveolar dead space in normal, healthy people
  66. How is physiologic dead space measured?
    Bohr's method
  67. What does Bohr's method do?
    • Assumes any measurable volume of CO2 in MIXED EXPIRED gas must come from alveoli that are BOTH perfused and ventilated
    • It measures the volume that does NOT eliminate CO2
  68. What is normal minute ventilation?
  69. What is minute ventilation?
    • Volume of gas EXPIRED per minute
    • Vt + RR
    • NOT equal to the volume of air entering and leaving the alveoli per minute
  70. What is the symbol for minute ventilation?
  71. What is alveolar ventilation?
    Volume involved in gas exchange per minute
  72. What is the symbol for alveolar ventilation?
  73. How is alveolar ventilation related to PaCO2?
    • Inversely related
    • Hyperventilation will lower PaCO2
    • Hypoventilation will increase PaCO2
  74. What is a shunt?
    Perfusion without ventilation
  75. What is dead space?
    Ventilation without perfusion
  76. What is the normal Deadspace : tidal volume ratio?
    • 0.3
    • This is the dilution factor
    • 30% of every tidal volume = deadspace
    • 70% is alveolar ventilation
  77. What are situations involving V/Q mismatch?
    • 1) pulmonary emboli
    • 2) low venous return causing low right heart output (hemorrhage)
    • 3) high alveolar pressure
    • 4) PEEP