tt2

• list the 4 functions of the respiratory systems

  1. gas exchange
  2. pH regulation (CO2 and H ions)
  3. defense from pathogens (mucous)
  4. vocalization
• upper respiratory tract is above the neck
• pleural sacs function

  • lubrication
  • sunction
• gas exchange occurs at the alveoli
• air is warmed to 37 ° and 100% humidity
• goblet cells secrete mucus
• anatomical dead space: space filled with air but no gas exchange
• type I alveoli cells

  • big
  • gas exchagne
• type II alveoli

  • small
  • surfactant production
• heart failure

  • RV hypertrophy (right side of heart working too hard)
  • too much force in lung
  • lung fills with fluid
• tidal volume: regular breathing
• Inspiratory reserve volume (IRV): maximum intake
• expiratory reserve volume (ERV): maximum exhale
• residual volume: volume always remaining in your lungs
• total lung capacity: everything including residual volume
• vital capacity: IRV+TV+ ERV
• obstructive

  • bronchioles are constricted
  • decrease in IRV, ERV
  • increase in RV
• inspiratory restrictive

  • decrease IRV, TV
• expiratory

  • decrease ERV
• forced expiratory volume (FEV): vol air forcefully exhaled in 1st second
• FEV/FVC ratio = 80%
• obstructive disease

  • FEV/FVC = 42%
  • improved by bronchodilators
• restrictive

  • FEV/FVC = high (90%)
  • each # are lower
• Boyle's law: pressure and volume are inversely related
• breathing

  1. at rest, the diaphragm is up
  2. after inspiration: diaphragm contracts (down), thoracic (chest) volume increases
  3. after expiration: diaphragm relaxes (up), thoracic volume decreases
• air moves from high to low pressure
• inspiration: atmospheric p higher than alveolar p
• expiration: alveolar p higher than atmospheric p
• muscles used for inspiration

  • sternocleidomastoids
  • scalenes
  • external intercostals (lift ribs up and out)
  • diaphragm
• muscles used for expiration

  • usually inactive, active during exercise
  • passive
• intrapleural pressure

  • -3 mmHg
  • created by elasticity of ribcage and lung
  • allows lungs to fill thorax
• lung will collapse if pleural fluid is not there
• easy way to treat collapsed lung

  • wet cloth
• alveolar p

  1. changes due to volume changes
  2. reverses because of air entering/leaving = pressure builds or decreases thru in/expiration
• compliance

  • elastin fiber network
  • surface tension in alveoli
• elastic and compliance are inversely related
• slope of compliance

  • always negative
  • steep slope = more compliant
• surface tension increases elasticity of alveoli.

  overcome with surfactant
• surface tension is equal for all alveoli (of various sizes)
• most airway resistance is in trachea and bronchi