NURS 5315 Gastrointestinal Module 9 (GI System Anatomy and Physiology)

NURS 5315 Gastrointestinal Module 9 (GI System Anatomy and Physiology) Advanced Pathophysiology. Examine the anatomy and physiology of the GI system: 1. Differentiate between the organs which make up the upper gastrointestinal track and the lower gastrointestinal track. -The GI tract consists of the mouth, esophagus, stomach, small intestine, large intestine, rectum, and anus. -Upper GI tract - esophagus, stomach and duodenum (upper GI bleeds) -Lower GI tract - jejunum, ileum, colon and rectum (lower GI bleeds) 2. Explain the hepatoportal circulation anatomy and physiology. The hepatic portal vein collects blood from capillaries in visceral structures located in the abdomen and empties into the liver for distribution to the hepatic capillaries. Hepatic veins return blood to the inferior vena cava. 3. Discuss the effects of aging on the gastrointestinal tract.  Age related changes in the GI tract begins at age 50  Tooth enamel and dentin wear down→ more vulnerable to cavities  Teeth are lost as a result of: o Periodontal (gum) disease o Recession of gums o Osteoporotic bone changes o Brittle roots that fracture easily  Taste buds decline in number  Sense of smell diminishes  Sense of taste decreases  Salivary secretion decreases  Very old adults→ oral and sensory changes make eating less pleasurable and reduce appetite  Food not chewed or lubricated sufficiently→ difficulty swallowing  Esophagus develops decreased motility  Changes in upper esophageal sphincter (hx of stroke & dementia) affect swallowing and contribute to GERD  Gastric motility and volume decreases (secretion of bicarbonate & gastric mucus)  Decreased production of intrinsic factor→ inadequate small intestine absorption of vitamin B12 and pernicious anemia  Change in composition of the intestinal microflora→ increased susceptibility to disease  Intestinal absorption, motility, and blood flow decrease → impaired nutrient absorption  Proteins, fats, minerals(including Ca+ and Iron), and vitamins are absorbed slowly and in lesser amounts.  Absorption of carbohydrates is decreased  Intestinal transit time = delayed  Constipation (probably caused by lifestyle factors)  Rate of liver regeneration decreases  Liver function altered (usually a pathologic condition)  Liver blood flow and enzyme activity decreased (influence the efficiency of drug and alcohol metabolism)  Pancreas undergoes structural changes such as fibrosis, fatty acid deposits, atrophy  Pancreatic secretion decreases  Gallstone incidence increases