Cells, Cell-Talk and Mammalian Homeothermy

Abstract

Multicellular organisms have features of “design” and “strategy” that seem to imply some supra-cellular control by which the constituent cell functions are ordered in the service of the organismic whole. Thus, considered as an entity, there is a “wisdom of the body” (Starling 1923; Cannon 1932). This “wisdom”, however, is surely illusory. The only instructions for all the precisely reproducible cellular specializations and intracellular associations of multicellular life are those of the genes of every constituent cell. The genetic expression by which cells become structurally and functionally specialized is “switched on” by some environmental influence, and the subsequent expression of cell specialization is largely in terms of responsiveness of each individual cell to sensed changes in its environment. Part of the responsiveness of most cells is the creation of a change in the chemical and/or physical environments of other cells which, in turn, respond to these induced environmental changes.