Using original experimental method (partial, different extent emptying of stomach from contents in various parts of time after satiety condition--denying the food intake) the mechanosensoric, homeostatic function of the stomach was revealed while performing the chronic experiments on adult male dogs, while on puppies the ageing peculiarities of its formation was shown. On polyfistuled (stomach, proximal and distal parts of duodenum) adult dogs, it was demonstrated that duodenum participates in maintenance and formation of satiety only while complex irritation by chime of the interoreceptors of gastrointestinal tract in natural succession of digestion takes place together with the sensoric processes in stomach.