Which receptors respond to increases in PaCO2 during an acute apneic event?

Central chemoreceptors play a crucial role in the regulation of respiration in response to changes in carbon dioxide levels in the blood, specifically the partial pressure of carbon dioxide (PaCO2). During an acute apneic event, where there is a cessation of breathing, carbon dioxide levels in the blood can rise quickly. Central chemoreceptors, located in the medulla oblongata of the brain, are sensitive to this increase in PaCO2.

When PaCO2 increases, it leads to a decrease in the pH of the cerebrospinal fluid, which is detected by the central chemoreceptors. In response, these receptors stimulate the respiratory centers in the brain to initiate breathing again, thereby helping to restore normal levels of carbon dioxide in the body. This mechanism is essential for maintaining homeostasis and ensuring that the body's pH remains within a normal range, which is vital for proper cellular function and overall health.

Peripheral chemoreceptors, while also involved in sensing changes in blood gases, primarily respond to the levels of oxygen (PaO2) rather than carbon dioxide. Baroreceptors monitor blood pressure and mechanoreceptors are involved in sensing mechanical changes in the body, thus are not directly related to the response to changes in PaCO