A model can be defined as an abstraction of reality which accounts for
those properties of a phenomenon that are pertinent to the purpose of
the model. Models are used in anesthesia to understand the various ph
ysiologic, pharmacological and physical processes that occur during an
esthesia. Indeed, many different types of models that comply with our
definition can be distinguished. Early models consisted of electrical
models of the arterial blood dynamics and cardiovascular system. Physi
cal models of drug uptake and distribution have been developed to expl
ain the kinetics of volatile anesthetics in the body. The goal of this
paper is to introduce the reader to some of the types of models that
been used to facilitate education and research in anesthesia. These ex
amples will elucidate the steps involved in developing a model and the
various types of models that have proven useful.