Week 21: (C.3) Neuroanatomy & Neurophysiology of breathing Flashcards
What is the pathway of regulation of involuntary breathing rhythm?
sensors —> controller —> effectors
What are the sensors for the involuntary breathing rhythm?
Central chemoR
Peripheral chemoR
stretch R
allergen and irritant R
What innervates the peripheral chemoR?
increased PCO2
decreased PO2 & pH
What is the function of the central chemoR?
Monitor pCO2 in
cerebral spinal fluid (CSF).
What is the function of the peripheral chemoR?
Monitor PO2, PCO2 and pH in blood and mixed lung gases.
Carotid Body (blood) Neuroepithelial Bodies (airway)
What are the other receptor inputs?
stretch R
allergens and irritant Receptors
What is the function of the stretch R?
> Hering-Breuer reflex:
Inhibition of lung over-inflation (>50% resting tidal)
Increased breathing frequency following rapid lung deflation (exhalation→ pant).
What is the function of allergens and irritant Receptors?
Feed into Vagus
Cough, sneeze and bronchoconstriction reflex
What does the central chemoR detect?
pH changes caused by increased PaCO2 in CSF
What does the peripheral cemoR detect?
decreased PaCO2 in the blood and airway. (less responsive to increased PaCO2 and decreased pH)
What receptor has a linear response mode?
central chemoR
What is the location of the central chemoR?
medulla (surafce)
What is the location of the peripheral chemoR?
arteial vasculature & airway
What contributes more to normal control of breathing?
central chemoR 80%
What has the faster response time?
Peripheral chemoR
seconds
Can the peripheral chemoR be altered by training?
NO
What does the central chemoR control?
system for normal breathing
What does the central chemoR respond to?
CO2 driven pH changes in Cerebral Spinal Fluid (CSF)
Changing Alveolar pCO2 (pACO2)