SACCM 14: Control of Breathing Flashcards
Where in the brain is the central pattern generator located?
throughout the medulla but concentrated in one region = pre-Boetzinger complex
What is the Pre-Boetzinger complex?
the respiratory central pattern generator
* creates intrinsic respiratory pattern
* pacemaker
What are the 3 phases of the respiratory pattern?
- Inspiratory phase
- Postinspiratory phase or Expiratory phase I
- Expiratory phase or Expiratory phase II
Where are the central chemoreceptors located and what do they respond to/sense?
primarily within the medulla
* respond to pCO2 and pH changes
Where are the peripheral chemoreceptors located and what do they respond to/sense?
aortic and carotid bodies
sense hypoxemia, can also be influences by pCO2 and pH but to lesser degree
How do the central chemoreceptors become desensitized to high pCO2
do not intrinsically become desensitized over time, but the CNS increases compensatory HCO3- concentration –> ventilation becomes normal again and over time respiratory response to high pCO2 is blunted
Between the carotid and aortic bodies which ones affect respiration more
carotid bodies have greater response for respiration wherease aortic bodies affect the circulation more
What type of cells sense the PaO2?
type I cells aka “glomus” cells
What 2 nerves are the peripheral chemoreceptors closely related to and transmit information to the CNS?
glossopharyngeal nerve (carotid bodies)
vagus nerve (aortic bodies)
What is the “Hering-Breuer inflation reflex”?
when there is excessive and sustained distention of the lungs -> pulmonary stretch receptors inhibit inspiratory discharge -> protective feedback loop
What receptors within the lungs lead to rapid/shallow breathing in patients with interstitial edema?
J receptors (within pulmonary interstitium, close to pulmonary capillaries)
Through which receptors does blood pressure affect respiration?
arterial baroreceptors
* marked decrease in BP -> reflex hyperventilation
* marked increase in BP -> reflex hypoventilation
