CSB346H1 Lecture Notes - Lecture 6: Peripheral Chemoreceptors, Central Chemoreceptors, Extracorporeal
Document Summary
Chemoreceptors provide information about blood/tissue levels of o2 and co2. Carotid bodies = o2 and co2 chemoreceptors. Cns = co2 chemoreceptors: co2/ph levels are related to acid-base balance in the blood and brain, co2/ph levels reflect adequacy of lung ventilation to tissue metabolism. Gas exchange is partly by lamb and partly by extracorporeal circuit. Gas exchange is completely by extracorporeal circuit: pco2 by hyperventilation = apnea. Breathing is stopped: depends on state of consciousness (e. g. , anaesthesia) In wakefulness, hypocapnia causes breathing to stop briefly. Decreased during sleep: ventilation doubles for every 2 mmhg rise in pco2. Shows that there are two distinct thresholds for ventilatory response to increases in co2: central + peripheral (cb intact) When cb intact, rapid ventilatory response to increases in co2: central + no peripheral (cb denervated) When no cb/peripheral, delayed ventilatory response to increases in co2.
