Qualitative mathematical models of endocrine systems.

Some qualitative dynamical models of endocrine systems are considered and analyzed, with the reproductive endocrine system as an example. The models considered are systems of nonlinear ordinary differential equations describing the rates of change of the hormonal concentrations with time. This type of general approach, which requires only the incorporation of the basic qualitative features of the interactions present in the underlying system into the model, is a potentially powerful tool for elucidating possible mechanisms for observed qualitative patterns of hormonal dynamics.