Page 212 - Physiology and Pathophysiology MNU 2024-2025 نظرى

Clinical pharmacy 2024/2025 Level 2 Pharm D Physiology and Pathophysiology (MD303)

GIT pathophysiology

❖ Esophagus Disorders

1- Dysphagia:
▪ Difficulty swallowing.
▪ May be caused by obstruction of the esophagus or impaired motility of the esophageal walls.
▪ Obstruction may be caused by tumors, congenital narrowing or diverticula (see below).
▪ Neurologic disorders such as brain injury, stroke or Parkinson’s disease may affect voluntary
swallowing or peristalsis of the esophagus.

2- Achalasia:
▪ A condition caused by failure of the lower esophageal sphincter (cardiac sphincter) to relax and
allow food to enter the stomach.
▪ It may be related to defects in neural input to the esophagus.
▪ Achalasia is a chronic condition that causes distention of the lower esophagus that may lead to
chronic inflammation and eventual ulceration of the esophagus.
▪ The condition presents with dysphagia, vomiting and chest pain that is often exacerbated by

eating.
▪ Aspiration of esophageal contents into the lungs is possible when lying down.

3- Gastroesophageal reflux disease (GERD)
▪ GERD is a condition caused by the backflow of stomach contents into the esophagus.
▪ It results from weakness of the lower esophageal sphincter that normally blocks reflux of stomach

contents into the esophagus.
▪ Because of their high acid content (low pH), reflux of stomach contents will cause irritation and
inflammation of the esophagus that can lead to ulceration of the esophagus.

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