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PHYSIOLOGY:CHEMICAL REGULATION & CONCL. - Coggle Diagram
PHYSIOLOGY:CHEMICAL REGULATION & CONCL.
Central Chemoreceptors
Blood brain barrier >prevents volatile acids to cross(not sesed by brain)
CO2 can cross BBB>>into CSF>Produce H+>Stimulate brain chemoreceptors>stimulate Resp. centre motor afferents(change)
Sense acid contained in blood(form of CO2)
Effect of PaCO2 and ventilation
PaCO2 lower than normal>>breathing stops(APNEIC)
Linear relationship>>directly proportional
Effect of PCO2 lost in chronic hypercapnia
PERIPHERAL CHEMORECEPTORS
Stimuli>>increase in acid/PaCO2 / decrease in O2>>Sensitive to arterial pressure connected to barioreceptor stimulation
Activation of medulla resp. centre>>stimulate breathing characteristics
Aortic(nerve X) and Carotid bodies(nerve IX)>>innervated by vagus and glossopharyngeal>>signals to resp. centres>>bodies contain metabolic/perfusion sensitive cells-Glomus cells.
Effect of PaO2 on ventilation
Above normal level>>breathing mechanisms not responsive to paO2
Hypoxic drive>>O2 level low below 70mmHg
Partial pressure decreases>>ventilation increases
Effect of hypoxaemia>>enhanced by PaCO2 Increase
CONCLUSION
%O2 saturation(Hb-O2)-Pulse oximetry
O2 supply>depends on Resp. & Cardio systems>>ADEQUATE o2 DELIVERED TO TISSUES>VITAL ENERGY STORES
Purpose of regulation>>ensure optimum o2 content in blood , hence blood gas analysis is completed to monito adequate Pao2
co2(BYPRODUCT)