CSB346H1 Lecture Notes - Lecture 7: Common Carotid Artery, Peripheral Chemoreceptors, Central Chemoreceptors
Document Summary
Csb346 lecture 7 summary peripheral and central oxygen sensing. Main o2 sensor is the carotid body (cb) that adjusts ventilation. Oxygenated blood is pumped from the lungs to the brain via the carotid arteries. Cb are situated at the bifurcation of the common carotid arteries that sense o2 in the blood: changes in o2 chemoreceptor afferents nts vrg initiate respiratory reflexes. Regulation of breathing by hypoxia (e. g. , hypoxic ventilatory response: hvr is different in neonatal mammals than in adults. In neonates, the hvr is biphasic because hypoxia suppresses metabolism (e. g. , o2 consumption is low and co2 production is low), so there is a reduced drive to breathe. Phase 1 = increase in ventilation is attributable to increase in frequency and tidal volume. Phase 2 = decrease in ventilation due to suppressed metabolism. In adults, hypoxia does not suppress metabolism and therefore, the biphasic response is nullified.
