Respiratory

• Functions of the respiratory system:

  • Gas exchange
  • Regulates body pH
  • Olfactory
  • Sound production
• Upper tract:

  • Nose
  • Nasal Cavity
  • Pharynx
• Lower tract:

  • Larynx
  • Trachea
  • Bronchi
  • Lungs
• Pulmonary ventilation:

  • Air flow in/out lungs
• External respiration

  • Lung gas exchange
• Internal respiration

  • Tissue gas exchange
• Cellular respiration

  • ATP
• Conducting zone

  • To/from respiratory zone
  • Nasal cavity to terminal bronchioles
• Respiratory zone

  • Gas exchange
  • Respiratory bronchioles and alveoli
• Respiratory mucosa

  • Membrane that lines respiratory tree
  • Traps debris, dust, microbes, irritants
• Mucociliary defense

  • Mucus in tandem with cilia to propel mucus to pharynx
• Nose - functions

  • Respiratory airway
  • Filters inspired air
  • Humidifies air
• Paranasal sinuses

  • Mucus secretion
  • Lighten skull
• Pharynx

  • Air, food passage
  • Tonsils
  • Eustachian tubes
• Pharynx regions

  • Nasopharynx
  • Oropharynx
  • Laryngopharynx
• Larynx

  • Passageway of air between pharynx/trachea
• Trachea

  • "Windpipe"
  • Larynx to primary bronchi
  • ~5 in.
  • 16-20 C-Cartilages
• Bronchial Tree

  • Air passages branching into 23 orders
• Bronchioles

  • Tiny branch of air tubes in the lungs
• Alveoli

  • External respiration - O2/CO2 exchange
  • Alveolar macrophages
  • Type 1 alveolar cells
  • Type 2 alveolar cells
• Pulmonary surfactant

  • Type 2 alveolar cell
  • Lipid
  • Decrease surface tension
  • Prevent alveoli collapse
• Lungs

  • 3 Right lobes
  • 2 Left lobes
  • Apex, Base, Cardiac Notch, Hilum
• Pleural membranes

  1. Parietal pleura
  2. Visceral pleura
  3. Pleural space
  4. Pleural fluid
• Ventilation

  • Inspiration (inhalation)
  • Expiration (exhalation)
  • Depends on air pressure
• Inspiration

  • Air comes into lungs
  • Always active
  • Diaphragm contracts and flattens
  • External intercostal muscles elevate ribs
• Expiration

  • CO2 and water exit lungs
  • Either passive or active
  • Lungs, chest wall recoil back to origin
  • Thoracic volume decreases; pressure change
• Lung capacities

  • Tidal volume: 500 ml
  • Inspiratory reserve: 3100 ml
  • Expiratory reserve: 1200 ml
  • Vital capacity: 4800 ml
  • Total: 6000 ml