Chapter 29_1 flashcards
(14 cards)
Upper GI Tract: Components
The upper GI tract consists of the esophagus, stomach, and small intestine (duodenum, jejunum, ileum).
Esophagus: Basic Function & Sphincters
A tube-like structure that uses peristalsis to move food from the mouth to the stomach. It has two sphincters: the Upper Esophageal Sphincter (UES) and the Lower Esophageal Sphincter (LES).
Stomach: Basic Function & Key Secretions
The stomach digests food using a combination of muscular contractions and secretions. Key secretions include mucus (goblet cells), HCl and intrinsic factor (parietal cells), pepsinogen (chief cells), and gastrin (G cells).
Stomach’s Protective Mechanism
Gastric mucosal cells secrete Prostaglandin E2 (PGE2), which stimulates mucus production and bicarbonate secretion to protect the stomach lining from its own acid. NSAIDs block this protection.
Small Intestine: Primary Function
The primary site for absorption and digestion of nutrients, vitamins, and minerals, aided by a large surface area from villi and microvilli (the brush border).
Enterohepatic Circulation: Definition
The process where bile acids are reabsorbed from the ileum and returned to the liver to be recycled.
Dysphagia vs. Odynophagia
Dysphagia: Difficulty swallowing. Odynophagia: Painful swallowing.
Assessment of Upper GI Pain
Key questions include: Is the pain burning/gnawing? Does it occur with or between meals? Is it relieved by food? Are there nocturnal symptoms? This helps differentiate conditions like GERD and PUD.
Assessment of GI Bleeding: Hematemesis vs. Melena
Hematemesis: Vomiting of blood. Bright red indicates active bleeding; “coffee ground” appearance indicates blood has mixed with stomach acid. Melena: Black, tarry stools caused by digested blood in the stool.
Fecal Occult Blood Test (FOBT)
A test used to detect the presence of hidden (occult) blood in a stool sample, often used to screen for a slow, chronic GI bleed.
Key Diagnostic Tool for Upper GI Disorders
Upper endoscopy is the most accurate method. It allows for direct visualization, biopsy, and sometimes treatment of upper GI problems.
Helicobacter pylori (H. pylori): Significance & Testing
A bacterium that resists stomach acid, burrows into the stomach lining, and is a major cause of chronic gastritis and peptic ulcer disease. Can be tested for via serology (antibodies), rapid urease test on biopsy, stool antigen test, or urea breath test.
General Treatment: Proton Pump Inhibitors (PPIs) & H2-Receptor Antagonists (H2RAs)
PPIs (e.g., omeprazole) and H2RAs (e.g., famotidine) are common medications used to decrease the production of stomach acid, allowing inflamed or ulcerated tissue to heal.
Upper Gastrointestinal Bleed (UGIB): Acute vs. Chronic
Acute UGIB: A rupture, tear, or perforation causing sudden, immediate blood loss and potentially hypovolemic shock. Chronic UGIB: A small tear or lesion causing slow, gradual blood loss, often leading to iron-deficiency anemia.
