GASTRIC DISORDERS

Stomach predominantly acts as a food-reservoir, though the process of digestion also begins here. Various digestive juices are secreted in stomach including hydrochloric acid and intrinsic factor by parietal cells, pepsinogen by chief cells and mucus as well as some hormones, (e.g.

Gastric acid (normal gastric pH 1-1.5) facilitates hydrolysis of proteins, conversion of ferric iron into ferrous form, and activation of pepsinogen into active pepsin. Intrinsic factor of castle is essential for vitamin B₁₂ absorption. Pepsin initiates process of proteolysis, i.e. conversion of larger protein molecules into smaller peptides. Emulsification of fats and hydrolysis of triglycerides also begins in stomach, due to activation of lingual lipase and secretion of gastric lipase.

While gastric emptying starts soon after the entry of food, rate depends on the type of ingested food, with half-emptying time being ~15-20 minutes for liquids and ~90-120 minutes for solids.

Vomiting, hematemesis and abdominal pain are common manifestations of gastric disorders.

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