Confining effects of pre-filled porous matrices and anisotropic polymer networks formed during the polymerization of a small amount of prepolymer components in nematic liquid crystal matrices are studied. The pretransitional phenomena above the bulk nematic-isotropic phase transition temperature is modeled to determine the order parameter of the liquid crystal molecules at the surface of a submicrometer cylindrical cavity from magnetic resonance experiments, and to determine the order parameter of the polymer network formed in an anisotropic liquid crystal environment from birefringence measurements. From this model, we estimate the size of the internal surface of the polymer network.