The Regulation of Ventilation

[Lorenzo]

Ventilation, particularly alveolar ventilation, is driven by the input of chemoreceptors to the central nervous system.

There are two groups of receptors and they are :

1. Central chemoreceptors

2. Peripheral chemoreceptors


Function includes:

The receptors directly monitor and are stimulated by cerebrospinal fluid and CO2. The hydration of CO2 and subsequent dissociation of H2CO3 in the CSF generates H. These receptors are  very sensitive and represent the main drive for ventilationunder normal resting conditions at sea level.

Therefore, the main drive for ventilation is CO2 (H).

[Lorenzo]

Physiologically speaking, we have to differentiate the difference between central and peripheral chemoreceptors because the latter differs in specificity as compared to the former.

Peripheral chemoreceptors, distinct from central , are less sensitive than the central chemoreceptors, but they still contribute to the normal drive for ventilation. These receptors, do not adapt, unlike the central chemoreceptors, which are adaptive.

By convention, under normal resting conditions and for practical purposes, the total drive for ventilation is CO2, mainly via the central chemoreceptors but with a small contribution via the peripheral.