What causes the increased damage to the gastric mucosa in duodenal ulcers?

In duodenal ulcers, the increased damage to the gastric mucosa is primarily attributed to the elevated secretion of hydrochloric acid (HCl) and the presence of pepsin. This excess acid, often a result of heightened gastric acid production, can lead to an imbalance in the protective mechanisms of the gastric lining.

Normally, the gastric mucosa is protected by a layer of mucus and bicarbonate, which neutralizes any excess acid. However, when there is an overproduction of HCl, the protective mechanisms may become overwhelmed, resulting in damage to the gastric mucosa. Pepsin, an enzyme that aids in protein digestion, also contributes to mucosal injury when the gastric environment is overly acidic, as it can further break down the protective barrier.

Thus, the combination of high concentrations of HCl and the activity of pepsin creates an environment in the stomach that can lead to ulcer formation and damage to the gastric mucosa. This highlights the importance of maintaining a balance between acid secretion and mucosal defense for gastrointestinal health.