In the paper [1], the micromorphic theory of heterogeneous bodies (mixtures) applied to the case of a one-dimensional body, i.e. rods, and the derived laws of balance both for one component and for the heterogeneous body (mixture) as a whole are presented. Using the laws of mass balance, microinertia tensor, amount of motion and energy for the case of micropolar rod theory, the constitutive equations for first and second order stress tensors and stress coupling were derived. The constitutive equations were derived in the absence of chemical reactions as in paper [3], and since it is a rod as a one-dimensional body, the interactions between the constituents are neglected. Despite these neglects, the constitutive equations are of a more general character than the existing ones, because it is assumed that a heterogeneous body consists of an arbitrary number of components, not just two.