title: A mathematical simulation of the hyperneas of metabolic CO2 production and inhalation.
abstract: Mathematical models of the CO2 responsive controller for ventillatory responses to CO2 inhaled and to CO2 introduced in the perpheral tissues are formulated in the context of a controlled system that is a compartmented tissue system with a lung undergoing breathing movements. Equations representing the system are either ordinary difference-differential equations or algebraic equations. If the controller contains three components simulating, respectively, a proportional controller with a set point, a mechanism sensitive to trans-membrane CO2 gradients, and a mechanism responsive to the autocovariance difference in arterial carbon dioxide tension (PaCO2) about 1.2 s apart; and if the neural tissues produce CO2 as a result of their own activity (positive feedback), the entire system responds to metabolic production of CO2 by increasing ventilation in proportion to metabolism while maintaining a constant PaCO2. The same system responds to inhaled CO2 mixtures with ventilation increasing in proportion to increases in PaCO2. The behavior of the model is used to postulate a spatiotemporal hypothesis for the humoral component of respiratory regulation of CO2 exchanges.
mesh_terms: D002245:Carbon Dioxide / Q000502:physiology*; D006439:Hemodynamics; D008660:Metabolism; D008954:Models, Biological; D012119:Respiration; D014018:Tissue Distribution
chemical_list: D002245:Carbon Dioxide