Involvement of cardiac, respiratory and gastrointestinal functions in neural responses to stressful events.

In the stress concept, fight and flight situations as well as other CNS-controlled reaction patterns for alertness to danger have to be followed by or integrated with a restorative "build-up" process in order to maintain homeostasis. The "build-up" process can be studied physiologically for example after regular exercise or training. Under these conditions there is a decrease in resting sympathetic adrenergic activity and an increase in the parasympathetic vagal activity. A theoretical model for the "build-up" process in psychosomatic gastroenterology has previously been presented. The present paper deals with the "build-up" process in cardiovascular and respiratory tract diseases seen in athletes. Anorexia nervosa related to excess physical training is also discussed as well as the "build-up" process in severe obesity and psychosomatic gastroenterological disorders.