Please enable JavaScript.

Coggle requires JavaScript to display documents.

Gas exchange 02:alveoli- blood and CO2:blood- Alveoli - Coggle Diagram

- - - - Trachea-conduct air
      - Bronchi- distribute air into lungs
      - Bronchioles- regulate airflow resistance
      - Functions
        
        Conduct airflow to alveoli
        
        Mucociliary clearance
        
        Clinical Example
        
        Bronchospasm in asthma → wheeze + reduced airflow
  - - - Alveoli
        
        Type I pneumocytes → gas diffusion
        
        Type II pneumocytes → surfactant production, prevent alveoli from collapsing
        
        Alveolar-capillary membrane
        
        Function
        
        Site of oxygen and carbon dioxide exchange
        
        Clinical Example
        
        Pulmonary oedema → fluid-filled alveoli impair diffusion
  - - - Filters air
      - Humidifies air
      - Warms inspired gases
      - Clinical Example
        
        Upper airway obstruction → stridor, increased work of breathing
  - - - gas transport
      - exchange with alveoli
      - Function
        
        Carry deoxygenated blood to alveoli
        
        Allow diffusion across membrane
        
        Clinical Example
        
        Pulmonary embolism → reduced perfusion
- - - - ↑ volume = ↓ pressure
      - Clinical Example:
      - Neuromuscular weakness
      - → hypoventilation → ↑ PaCO₂
  - - - Alveoli → blood
    - - Blood → alveoli
    - - • Pressure gradient
      - • Thin membrane
      - • Large surface area
    - - Gas transfer depends on:
      - • Surface area
      - • Membrane thickness
      - • Pressure gradient
  - - - Normal ≈ 0.8
  - - - Right shift:
      - • Acidosis
      - • Fever
      - • Hypercapnia
  - - - COPD → CO₂ retention → respiratory acidosis
- - - - ↑ thoracic volume
      - ↓ intrapulmonary pressure
      - → air enters lungs
  - - - proportional to pressure
  - - - • Large surface area
      - • High pressure gradient
    - - • Thick membrane
- - - - Dissolved in plasma
      - Bound to haemoglobin
    - - mostly bicarbanate
- - - - Clinical Example
        
        Type 1 respiratory failure:
        
        PaO₂ ↓
        
        PaCO₂ normal/low
        
        Clinical Example
        
        Type 2 respiratory failure:
        
        PaO₂ ↓
        
        PaCO₂ ↑
    - - pH
      - PaO₂
      - PaCO₂
      - HCO₃⁻
      - SaO₂