It shows mucosa of stomach. Reticular blood vessels stretched underneath the mucosa have been seen. Gastric mucosa with its secreting mucus is protected from gastric acid and digestive juice in order not to be digested by them. It is known that NSAIDs (Nonsteroidal Anti-Inflammatory Drugs), which provides pain-killing and antipyretic effects, cause the suppression of gastric mucous secretion by immediate dysfunctions of mucous cell besides the inhibition of blood flow in stomach. As hydrochloric acid is added in the concentration equal to gastric acid over gastric mucosa whose defense has been weakened by the administration of NSAIDs, the mucosa is being damaged and starts bleeding. In this way, when the balance between protection and aggressive factors gets upset, gastric ulcer can occur by gastric mucosa’s desquamating.

In stomach, protein as a food is digested by strong-acid gastric juice containing hydrochloric acid and digestive enzyme. Nevertheless, why isn’t the mucosal tissue of stomach, which also consists of protein, digested by the acid juice?Tons of mucous cells are present in gastric mucosa, covering the surface of stomach. And they secrete and form mucous layer of bicarbonate (to neutralize an acid) and mucin. In this way, gastric mucus is protecting the mucosal tissue of stomach from strongly acidic gastric juice. This footage shows a state of secreting mucus from mucosa of stomach.