Peripheral chemoreceptors and medullary respiratory center

The peripheral chemoreceptors and medullary respiratory center constitute the primary physiological system responsible for the autonomic control of breathing (StatPearls, Physiology, Respiratory Drive). Peripheral chemoreceptors, located in the carotid and aortic bodies, primarily sense changes in arterial oxygen tension (PaO2), while the medullary respiratory center contains central chemoreceptors sensitive to changes in pH and carbon dioxide (PaCO2) in the cerebrospinal fluid (Guyton and Hall, Textbook of Medical Physiology). Together, these components integrate chemical signals to modulate the activity of respiratory muscles, ensuring adequate gas exchange and acid-base balance. This system is a critical target for respiratory stimulants like doxapram, which acts by inhibiting potassium channels in the carotid body and stimulating medullary neurons (DrugBank, Doxapram). Conversely, it is a site of adverse action for CNS depressants such as opioids, which can lead to fatal respiratory depression by reducing the system's sensitivity to CO2 (PubMed, PMC6307543). Dysregulation of this system is implicated in clinical conditions such as sleep apnea, obesity hypoventilation syndrome, and sudden infant death syndrome (NIH, NHLBI).

Other names

Carotid bodyAortic bodyRespiratory control centerMedullary rhythmicity areaCentral chemoreceptorsPre-Bötzinger complex

Stimulation of peripheral chemoreceptors (carotid bodies) and direct activation of medullary respiratory neurons to increase ventilatory drive.