Presented experimental investigations aimed at studying the immune component of the mucous membrane of the jejunum as the most active segment of the small, in which the processes wall, membrane and intracellular digestion occur with the greatest severity. These processes implement homeostasis at the level of the whole organism. All changes after the general γ -irradiation in small doses led to a decrease in the barrier-protective functions. In this paper the authors note the failure of the prolonged post-radiation monitoring period to restore structural component, although some of them returned to normal. The morphological and functional changes were characterized by a barrier imbalance of indicators of optical density of sialomucin gel and alkaline phosphatase, tuckaleechee population on the background of a strong correlation relations including interaction in mitotic cells and intraepithelial lymphocytes. Thus, it was observed interoperability and the fat cells showed radioprotective effect. Lymphoid tissue through the formation of lymphocytic infiltrate in the epithelium and M-cells, as well as lymphocytic-plazmocitomom in the subepithelial layer with lymphoid nodules testified to the disadvantage of homeostasis.