Page 214 - Physiology and Pathophysiology MNU 2024-2025 نظرى

Clinical pharmacy 2024/2025 Level 2 Pharm D Physiology and Pathophysiology (MD303)
▪ Ulceration of the gastrointestinal mucosa is caused

by disruption of the normal balance of the
corrosive effect of gastric juice and the protective
effect of mucus on the gastric epithelial cells.
▪ It may be viewed as an extension of the cell
damage found in gastritis.
↓↓protective Mucosa

▪ The underlying causes are not known but, if factors associated with the maintenance of healthy
mucosa are defective, acid gastric juice gains access to the epithelium, causing the initial cell
damage that leads to ulceration.
▪ The main factors are:
1- Blood supply: Reduced blood flow and ischemia may be caused by:
• Excessive cigarette smoking
• Stress, either physical or mental. In a stressful situation there is an increase in the secretion of
noradrenaline and adrenaline and this cause constriction of the blood vessels supplying the
alimentary tract.

2- Secretion of mucus: The composition and the amount of mucus may be altered, e.g.:
a) Regular and prolonged use of aspirin and other anti-inflammatory drugs
b) Chronic gastritis.
↑↑↑Gastric acid secretion
▪ The hormone gastrin stimulates the production of acid in the
stomach; therefore, any factors that increase gastrin production
will in turn increase the production of stomach acid.
▪ Zollinger–Ellison syndrome: Tumors of the gastrin-secreting

endocrine cells of the pancreas or, less frequently, the duodenal
wall. Leads to excessive acid production by the G.I. tract.
Development of serious and aggressive peptic ulcers.
Complications can include perforation, hemorrhage and
obstruction.
❖ The causes of peptic ulcer disease include the following:
a) Infection with the bacteria Helicobacter pylori occurs in 80 to 95% of patients with peptic ulcer
disease.
b) Stress — Emotional, trauma, surgical.
c) Chronic use of aspirins and NSAIDs.
d) Injury or death of mucus-producing cells.

e) Excess acid production in the stomach (Zollinger–Ellison syndrome)
❖ Complications of peptic ulcers:
1. Hemorrhage.
▪ Acid gastric juice may cause the development of many tiny ulcers, or gastric erosions, leading to
multiple capillary bleeding points and possibly iron deficiency anemia.
▪ When a major artery is eroded a serious and possibly life-threatening hemorrhage may occur,
causing:

| P a g e 148