2410 GI PowerPoint - FA23 (1)

Introduction

• Course: NURS 2410 - Pathophysiology

• Instructor: Dr. Amit Mitra, M.D., Ph.D.

• Institution: Franciscan Missionaries of Our Lady University

• Contact: amit.mitra@franu.edu

Chapter 17: Digestive System Disorders

Learning Objectives

• Students will be able to:

  • Describe the various causes of vomiting.

  • Differentiate diarrhea from constipation.

  • Explain the common causes of dysphagia.

  • Differentiate the types of hiatal hernias and explain their effects.

  • List the causes of acute gastritis and describe the common signs.

  • Compare the effects of acute gastritis, chronic gastritis, and gastroenteritis.

  • Describe the etiology, signs, and possible complications of peptic ulcers.

  • Explain how pyloric stenosis interferes with normal function and list the common manifestations.

  • Describe how gallstones develop and the signs of obstruction.

  • Differentiate the types of jaundice.

  • Describe the common manifestations of hepatitis.

  • Differentiate the types of cirrhosis.

  • Describe the pathophysiology and manifestations of cirrhosis.

  • Describe the pathophysiology, signs, and possible complications of acute pancreatitis.

  • Explain how gluten toxicity may affect individuals with celiac disease.

  • Describe the signs of malabsorption.

  • Compare Crohn disease with ulcerative colitis.

  • Describe the stages in the development of acute appendicitis and the signs associated with each stage.

  • Explain how diverticulosis and diverticulitis develop.

  • Describe the common causes of intestinal obstruction.

  • Explain the progressive effects of intestinal obstruction and the related signs.

  • Differentiate chemical peritonitis from bacterial peritonitis, including causes for each.

  • Describe the pathophysiology of peritonitis and possible complications.

Anatomy Overview of the Digestive System

• Mouth

  • Hard palate, tongue, teeth

  • Salivary glands (parotid, submandibular, sublingual)

  • Function: Chewing food, adding saliva (water and digestive enzymes) to begin digestion

• Esophagus

  • Structure: Muscular tube between the pharynx and stomach

  • Function: Swallowing food

• Stomach

  • Functions: Mixing food with gastric secretions to form chyme, digesting protein, and absorbing specific nutrients like intrinsic factor

• Small Intestine

  • Structures: Duodenum, jejunum, ileum

  • Functions: Digestion (bile emulsifies fats; pancreatic and intestinal secretions digest fats, proteins, and carbohydrates) and nutrient absorption

• Large Intestine

  • Structures: Colon (ascending, transverse, descending), cecum, appendix, sigmoid colon, rectum, anus

  • Functions: Absorbing water and electrolytes, storage until defecation

Common Manifestations of Digestive System Disorders

Anorexia

• Definition: Lack of appetite

• Associated conditions: Various disorders

Nausea

• Definition: Feeling of uneasiness that often precedes vomiting

• Stimuli:

  • Distention or irritation of the digestive tract

  • Inflammation

  • Sensory stimuli (smells, visuals)

  • Pain and chemical toxins or drugs

Vomiting

• Definition: Reflex mechanism expelling contents of the stomach (emesis)

• Consequences: Dehydration, electrolyte imbalances, acidosis, malnutrition

• Stimuli: Includes systemic infection, uremia, emotional responses, motion sickness, brain pressure, and pain

• Characteristics of Vomitus

  • Hematemesis: Presence of blood in vomit indicating GI bleeding (coffee grounds from HCl action on hemoglobin indicates lower GI bleed)

  • Fresh blood indicates upper GI bleeding (esophagus)

  • Bile indicates yellow-green vomitus

  • Dark brown content suggests intestinal obstruction

Dysphagia

• Definition: Difficulty swallowing

• Causes:

  • Neurological disorders (stroke, achalasia)

  • Muscular disorders (muscular dystrophy)

  • Mechanical obstruction (e.g., tumors, congenital atresia, stenosis due to GERD)

• Clinical Manifestations:

  • Pain during swallowing

  • Inability to swallow solid food, progressing to liquids

Diarrhea

• Definition: Excessive frequency of stool, often loose or watery

• Common with nausea and vomiting, especially during GI infections

• Dangers: Prolonged diarrhea leads to dehydration, electrolyte imbalance, acidosis, and malnutrition

• Types of Diarrhea

  • Large-volume (secretory/osmotic): Watery due to infections

  • Small-volume: Mucous with blood, seen in Crohn's and ulcerative colitis

  • Steatorrhea: Fatty diarrhea associated with malabsorption syndromes (e.g., celiac disease, cystic fibrosis)

Blood in Stool

• Definitions:

  • Frank blood: Visibly seen, indicates lesions (hemorrhoids).

  • Occult blood: Hidden, detectable via stool tests, indicates upper GI bleeding

  • Melena: Dark, tarry stool from sig nificant upper GI tract bleeding

Malnutrition

• Causes: Decreased digestion and absorption of nutrients, leading to

  • Limited malnutrition: one or two nutrient deficiencies

  • Generalized malnutrition: multiple nutrient deficiencies

• Associated conditions: Chronic anorexia, vomiting, diarrhea, and intestinal disorders

Types of Pain in the Digestive Tract

• Types include:

  • Somatic Pain: Sharp, well-localized pain (e.g., abdominal wall irritation)

  • Visceral Pain: Poorly localized, dull or cramping pain from internal organs

  • Referred Pain: Pain perceived in a different location than the site of the stimulus (e.g., appendicitis pain in the peri-umbilical region)

Characteristics of Pain

• Types of pain based on sensation:

  • Burning pain (e.g., heartburn from inflammation)

  • Dull, aching pain (e.g., stretching liver capsule)

  • Cramping pain: Characteristic of intestinal inflammation or distention

  • Colicky pain: Arising from muscle spasms during severe inflammation or obstruction

Basic Diagnostic Tests

• Imaging Techniques:

  • Radiography: Using contrast media to assess blockages

  • Ultrasound: Identifying unusual masses

  • CT and MRI: Detailed imaging

  • Fiberoptic endoscopy: Assessment of upper GI tract

  • Sigmoidoscopy/colonoscopy: Evaluation of lower GI tract, potential biopsy for study

• Laboratory Tests:

  • Stool specimens: Check for infection, parasites, bleeding

  • Blood tests: Liver function tests, pancreatic function, tumor markers (e.g., CEA for colon cancer)

Upper Gastrointestinal Tract Disorders

Hiatal Hernia

• Definition: Part of the stomach protrudes into