A stochastic model for biological tissue elasticity in simple elongation

A mathematical model is described which predicts the effective tangent moduli of biological tissues at each deformed state, which accounts for the contributions of two major load-bearing components - collagen and elastin. The problem is studied from a stochastic point of view based upon the theory of composite materials. It is shown that a simple stochastic model is possible and it can be expressed simply in terms of the volume fractions of collagen and elastin fibers and of the 'collagen arrival density'. The model is then used in the discussion of stress-strain relationships of the alveolar wall in simple elongation.