Simulation of Biological Systems: Contraction of Skeletal Muscle

The simulations to be discussed here assume that force is developed at independent tension generators, and they identify those tension generators with the cross bridges seen in electron micrographs. These simulations attempt to de duce how the cross bridges behave under various circum stances, an essential preparatory step for discovering the actual force-producing phenomena. The mechanical proper ties of each individual cross bridge need not mirror those of the whole muscle. The number of cross bridges partici pating in tension development can vary, and some may be impeding contraction while others aid it. Therefore, one cannot easily predict whether cross bridges with any par ticular kind of behavior will produce behavior characteristic of whole muscle. Such predictions are possible with models and simulation. This review describes two specific cross bridge models, representing two general classes of models. It shows how the predictions of simulations led to a specific experiment whose outcome favored only one of these classes.