Intro to GI, Assessment, & Dx Tests NRS 101

Introduction to the Gastrointestinal System

  • Overview of the anatomical structure and physiological function.

  • Importance of the gastrointestinal system in digestion and nutrient absorption.

Anatomy of the Gastrointestinal Tract

  • Also known as the digestive tract or alimentary canal.

  • Muscular tube approx. 30 feet long from mouth to anus includes:

    • Mouth

    • Pharynx

    • Esophagus

    • Stomach

    • Small Intestine

    • Large Intestine

    • Anus

Functionality and Process

  • Peristalsis:

    • Rhythmic contractions of smooth muscle push food through the digestive tract.

    • Essential for transportation of food.

  • Accessory Organs:

    • Not part of the digestive tract but aid in digestion by releasing chemicals through ducts:

      • Teeth

      • Tongue

      • Salivary glands

      • Liver

      • Gallbladder

      • Pancreas

      • Appendix

The Mouth

  • Introduction to the digestive system starting point.

  • Tongue Functions:

    • Aids in chewing, swallowing, and taste.

    • Papillae contain taste buds.

    • Digestion starts with enzyme activity.

  • Teeth Types:

    • Incisors: For biting and cutting.

    • Canines: For tearing and shredding.

    • Molars: For crushing and grinding (mastication).

  • Salivary Glands:

    • Types include parotid, submandibular, and sublingual.

    • Saliva is 99% water, with enzymes for digestion.

    • Secretion rate: 1,000 to 1,500 mL/day.

The Esophagus

  • Muscular tube connecting mouth to stomach.

  • Functions in peristalsis to move food bolus to the stomach in 5-6 seconds.

The Stomach

  • Location: Left upper abdomen beneath the diaphragm.

  • Capacity: 1 to 1.5 liters, size roughly of a football.

  • Sphincters:

    • Cardiac sphincter (entrance) prevents reflux.

    • Pyloric sphincter (exit) controls chyme passage.

  • Chyme formation through mixing food with gastric juices.

The Small Intestine

  • Approx. 20 feet long, 1-inch diameter.

  • Sections: Duodenum, jejunum, ileum.

  • Key Roles:

    • 90% of digestion occurs here.

    • Absorption aided by villi that increase surface area.

The Large Intestine

  • Length: 5-6 feet, diameter of 2 inches.

  • Parts include: Cecum, appendix, ascending colon, transverse colon, descending colon, sigmoid colon, rectum, anus.

  • Functions:

    • Absorption of water.

    • Vitamin manufacturing.

    • Feces formation and expulsion.

  • Bacterial Role:

    • Converts chyme into feces.

    • Engages immune system tissues.

The Liver

  • Location: Inferior to the diaphragm in upper right abdomen.

  • Blood supply: 1,500 mL/min from portal vein and hepatic artery.

  • Produces bile for fat breakdown.

  • Functions: Numerous; detailed in foundational texts.

The Gallbladder

  • Pear-shaped organ; connects to liver.

  • Stores and ejects bile into the duodenum.

The Pancreas

  • Located posterior to the stomach.

  • Produces pancreatic juices (protease, amylase, lipase).

  • Neutralizes gastric acid and regulates glucose.

Assessment of the GI System

  • Health History:

    • Inquiries about abdominal pain, bowel pattern changes, weight fluctuations, previous GI disorders.

    • Medication inquiries (NSAIDs, antacids).

    • Nutrition assessment: Food/fluid intake habits and allergies.

  • Physical Assessment:

    • Observe general appearance for signs of nutritional deficiencies:

      • Hair, skin, eyes, gums, tongue, and nails.

    • Assess chewing and swallowing capabilities, monitor energy levels and overall well-being.

Medical Measurements and Insights

  • Proper procedures for height and weight assessments.

  • Ideal body weight calculation formulas provided for men and women.

  • Definitions: Malnutrition, overweight, obesity, and relevant BMI categorizations.

  • Importance of skin fold measurements for health predictors.

Oral Assessment Techniques

  • Inspection of lips, tongue, buccal mucosa, teeth, gums, throat.

  • Conditions to recognize: angular cheilitis, glossitis, leukoplakia, candidiasis, gingivitis, and bad breath.

Abdominal Assessment Protocol

  • Patient prep: Bladder emptied, lie supine.

  • Steps: Inspect, auscultate, and palpate abdomen for signs of GI distress and abnormality.

  • Bowel Sounds: Definition and classifications (normal, hyperactive, hypoactive).

Laboratory Tests by Organ System

  • Liver: Serum albumin, bilirubin, liver enzymes, protein, and ammonia levels to monitor functionality.

  • Pancreas: Serum amylase and lipase to assess damage.

  • General: Lipid profiles.

Diagnostic Tests Overview

  • Upper GI Tests: Upper GI series, gastric analysis, endoscopy, capsule endoscopy.

  • Lower GI Tests: Occult blood, sigmoidoscopy, barium enema, colonoscopy, stool culture, obstruction series.

  • Accessory Organ Diagnostics: Cholecystography, T-tube cholangiography, ultrasound, and biopsy procedures.

  • Importance of specialized testing to confirm dysfunction and direct treatment.

Conclusion

  • Summary of the GI system's anatomy, physiology, assessment, and diagnostics.

  • Invitation for questions during the follow-up session.