Optical vortices are equally relevant for their fundamental features as beams with topological properties and applications in image processing, telecommunications, optical tweezers, and quantum information. The interaction of light beams with umbilical defects in liquid crystal cells is a natural source of optical vortices. Here we investigate, experimentally and theoretically, the mechanisms of the matter vortices that appear in liquid crystal cells and establish statistical laws that govern them. Based on an adequate stochastic equation, the law for the number of nucleated vortices as a function of anisotropy, bifurcation parameter, and noise level intensity is set. Experimental results show a fair agreement with the theoretical findings.