THE STOMACH AS A SYSTEM AND THE PATHOGENESIS OF EXPERIMENTAL ULCER

The stomach is prone to ulceration because of the hostile environment that exists within its lumen. The most important etiologic factor rema ins a topic of debate. We have considered the stomach as a system to l end insight into which pathophysiologic mechanisms might be most impor tant. Systems are described by their content, hierarchy, entropy and i nteractions. The states of health, disease and death (i.e. ulceration) are represented by progressively increasing levels of entropy. It is argued that many of the purported causes of ulcer disease, such as aci d back-diffusion or alcohol related necrosis, represent alterations in the system that affect small groups of cells that are low in the hier archy and cause the tissue to enter the diseased state. We hypothesize that because blood flow is high within the hierarchy it represents th e major homeostatic mechanism. If blood flow responds appropriately th e system may return to the healthy state. If it does not the death of the system results in ulceration. Experimental evidence to support the se contentions is presented.