We investigate the influence of the material in homogeneities that are generated by an isotropic growth on the source of mass acting within a growing living tissue. In order to do that, we need to study the interaction between these material in homogeneities and the chemical agents dissolved within the tissue. For this purpose, we use some ideas and methods from Condensed Matter Physics (e.g., the Path Integral technique employed in modeling Brownian processes) and apply them to the Continuum Mechanics description of volumetric Growth. We believe that this approach may provide new physical insight into the interactions between the macroscopic dynamics of living systems and the evolution of the subsystems which activate biological processes.