A Control Engineering Perspective of Calcium Homeostasis

摘要

Achieving calcium homeostasis in the human body, whereby extracellular fluid calcium is maintained within a narrow range (2.4±0.25mM) necessary for normal physiological function, is the task of a biological control system that is still not completely understood. Although general information is available on several of the component processes involved in calcium homeostasis, there is currently no mechanistic understanding of the emergent characteristics of the entire system. To this end, we present an engineering control framework for understanding calcium homeostasis, which is predicated on a configuration of the physiological system in terms of appropriately connected control system components (sensor, controller and actuator). Using information from the literature, we develop mathematical models for each component and integrate them into a holistic, comprehensive dynamic model of the complete system. The framework enables a more systematic study of observable physiological responses such as hypo- and hypercalcemia; it also allows us to interpret pathologies in terms of control system component defects.