Respiration 1

Subdecks (2)

Cards (40)

  • Main functions of the respiratory system
    • Transport of oxygen and carbon dioxide between the tissues and environment
  • Components of the respiratory system
    • Nose
    • Nasal cavity
    • Paranasal sinuses
    • Pharynx
    • Larynx
    • Trachea
    • Bronchi and bronchioles
    • Lungs and alveoli
  • Type I alveolar cells
    Predominant, simple squamous epithelium, main site of gas exchange
  • Type II alveolar cells

    Cuboidal epithelial cells containing microvilli, secrete fluid containing surfactant
  • Lung compliance
    Distensibility of the lungs. High lung compliance means the lungs will expand easily. Compliance is decreased in pulmonary edema, insufficient surfactant, and scar tissue.
  • Elastic recoil
    Lung's intrinsic tendency to deflate following inflation (inspiration), due to pulmonary elastic fibres and surface tension
  • Pulmonary surfactant
    Lipoprotein complex (70% lipid, mainly dipalmitoylphosphatidylcholine; 30% protein) produced by Type II alveolar epithelial cells, lowers surface tension so breathing can occur without too much effort, increases lung compliance and reduces the tendency of the lungs to recoil inward, makes the alveoli stable against collapse
  • As alveoli radii change
    Surface tension varies. At end of expiration, alveoli radii reduced, surfactant more compressed and more active, reducing surface tension. At end of inspiration, alveoli expanded, surfactant more diluted and less active, increasing surface tension.
  • Panting
    A controlled increase in respiratory frequency accompanied by a decrease in tidal volume, to increase ventilation of the upper respiratory tract, preserve alveolar ventilation and increase evaporative heat loss
  • Inspiration
    Active process, air moves into the lungs due to a decrease in air pressure within the lungs
  • Normal expiration
    Passive process, air moves out of the lungs due to an increase in air pressure within the lungs
  • Forceful exhalation
    The abdominal and internal intercostals muscles contract
  • Intrapulmonary/alveolar pressure

    The pressure of the air within the alveoli, changes during breathing, eventually equalizes with atmospheric pressure
  • Intrapleural/pleural pressure
    The pressure of the air within the pleural cavity, between the visceral and parietal pleurae, changes during breathing, is always lower than or negative to the intrapulmonary pressure
  • Transpulmonary pressure
    Represents the pressure that effectively promotes air flow and distends the lungs, the difference between the intrapleural pressure and the intrapulmonary pressure
  • Intrapleural pressure is normally negative
    Due to inward lung and outward chest wall recoil
  • In pneumothorax
    Air enters the pleural space, intrapleural pressure increases and lung volume decreases, can cause partial or complete lung collapse