ON THE PHYSIOLOGY OF METAZOA

The problem of integration and control of the various processes of the metazoan organism is a major challenge to the physiologist. The tradi tional research strategy in dealing with the problem is neuron-oriente d and its roots extend back into the last century when knowledge of ho rmones was lacking. In the present article, the traditional strategy i s analyzed in the light of available data and its logical basis is que stioned. Different levels of communication are supposed to occur in th e animal or human body. Circulating hormones are responsible for the h ighest level of communication that occurs between organs or tissues. T he central concept in the article is that regulation of circulating ho rmones constitutes a higher level of control relative to regulation of intercellular hormones. This is regardless of whether the latter occu rs in the nervous system or elsewhere. The approach is utilized in def ining the mechanism that integrates and controls the part processes of the body. The mechanism is defined as endothelial; the vascular endot helial system is the controlling part and the nervous system is one of the subordinate parts. Thanks to the new approach, meaningful biologi cal explanations of major psychiatric disorders are now possible.