Breathing during sleep is controlled by voluntary and behavioral factors in addition to metabolic
and mechanical factors.1 Chemical information is relayed through peripheral chemoreceptors in the carotid and aortic bodies. The carotid chemoreceptors, although small, have a uniquely high blood supply, and sense the arterial concentration of O2 and relay the information to the medulla. The carotid body chemoreceptors are responsible for about 90% of the ventilatory response to hypoxemia. Chemosensory function in the carotid bodies is immature at birth and increases with age. Carbon dioxide (CO2) is also sensed in the carotid body, accounting for 20% to 50% of the response to arterial hypercapnia. The remaining response to hypercapnia comes from central brainstem receptors in
the medulla. The central chemoreceptors respond primarily to changes in pH, mediated by CO2 tension,
in the cerebrospinal fluid. Laryngeal chemoreflexes (LCR) located in the epithelium that
surrounds the airway respond to acidic solutions with reflexes that include startle, swallowing, laryngeal
constriction, apnea, and bradycardia. Mechanical information sensed through receptors in the lung and chest wall are also relayed to the
Breathing during sleep is controlled by voluntary and behavioral factors in addition to metabolicand mechanical factors.1 Chemical information is relayed through peripheral chemoreceptors in the carotid and aortic bodies. The carotid chemoreceptors, although small, have a uniquely high blood supply, and sense the arterial concentration of O2 and relay the information to the medulla. The carotid body chemoreceptors are responsible for about 90% of the ventilatory response to hypoxemia. Chemosensory function in the carotid bodies is immature at birth and increases with age. Carbon dioxide (CO2) is also sensed in the carotid body, accounting for 20% to 50% of the response to arterial hypercapnia. The remaining response to hypercapnia comes from central brainstem receptors inthe medulla. The central chemoreceptors respond primarily to changes in pH, mediated by CO2 tension,in the cerebrospinal fluid. Laryngeal chemoreflexes (LCR) located in the epithelium thatsurrounds the airway respond to acidic solutions with reflexes that include startle, swallowing, laryngealconstriction, apnea, and bradycardia. Mechanical information sensed through receptors in the lung and chest wall are also relayed to the
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