USMLE

Nervous Control of Breathing

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Respiratory
  1. Respiratory Overview
  2. Airway Anatomy
  3. Alveoli
  4. Breathing Mechanics
  5. Gas Exchange in Tissues
  6. Nervous Control of Breathing
  7. Respiratory Defense Systems
  • Nervous Control of Breathing
    • Chemoreceptors detect pH (H+ concentration) in blood
      • pH is dependent on pCO2 in blood (indirect measure)
        • By way of bicarbonate buffer and carbonic anhydrase system
      • Central chemoreceptors in medulla
      • Peripheral chemoreceptors in carotid arteries and aorta
    • Chemoreceptors regulate the breathing/respiratory rate
      • At high pCO2 levels = more acid
        • chemoreceptors send signals to increase breathing rate
        • Allows more CO2 to be expired 
      • At low pCO2 levels = less acid
        • chemoreceptors send signals to decrease breathing rate