Page 34 - Control Theory in Biomedical Engineering

Modeling and control in physiology 21

Fig. 13 Control of body temperature by the hypothalamus causing constriction or
dilation of skin capillaries and sweat production.

Let’s note here that the roster of vital parameters concerned by homeo-
stasis is long. It includes blood pressure, heart rate, blood calcium and blood
glucose.
In order to maintain homeostasis in the cardiovascular system, blood
pressure and heart rate must be converging to reference states. In fact,
different external stimuli, such as stress, affects the equilibrium of blood
pressure. Blood pressure can so increase above or toward normal. Fig. 14
describes this control process. Moreover, when blood pressure increases

Fig. 14 Blood pressure homeostasis.