Nursing Assessment: Gastrointestinal System Chapter 39 Overview Copyright © 2011, 2007 by Mosby, Inc., an affiliate of Elsevier Inc.

2 Gastro intestinal system Gastro intestinal system Main function is to supply nutrients to body cells. This is accomplished by the processes : ingestion ( taking in food), digestion ( breaking down of food), and absorption ( transfer of food product into circulation). Elimination is the process of excreting the waste products of digestion. Copyright © 2011, 2007 by Mosby, Inc., an affiliate of Elsevier Inc.

3 Components of GI tract Mouth, esophagus, stomach, small intestines, large intestines, rectum and anus. Associated organs are: the liver, pancreas and the gall bladder. Factors outside GI tract that can influence its functioning: psychological and emotional factors such as stress and anxiety. Stress may be manifested by anorexia, nausea, epigastric and abd pain or diarrhea. Copyright © 2011, 2007 by Mosby, Inc., an affiliate of Elsevier Inc.

4 Fig Location of organs of the gastrointestinal system.

5 Structures and Functions of Gastrointestinal System Copyright © 2011, 2007 by Mosby, Inc., an affiliate of Elsevier Inc. Fig Anatomic locations of the large intestine.

6 GI system GI system GI systems should never be attributed solely to psychological factors. Physiological factors that affect the GI tract : the dietary intake, alcohol, caffeine, smoking, and poor sleep. Peptic ulcer disease and ulcerative colitis may be aggravated by stress. Copyright © 2011, 2007 by Mosby, Inc., an affiliate of Elsevier Inc.

7 Structures and functions of the GI system GI system extends from mouth to anus and is about 30 feet long The entire tract is composed of four common layers : mucosa, submucosa, muscle and serosa. GI tract is innervated by the autonomic nervous system : sympathetic and parasympathetic systems Sensory information is relayed by both sympathetic and parasympathetic system Copyright © 2011, 2007 by Mosby, Inc., an affiliate of Elsevier Inc.

8 GI system GI system Peristalsis is increased by parasympathetic system and decreased by sympathetic system GI tract also has its own nervous system enteric ( or intrinsic) : has the ability to control movement and secretion of the GI tract GI tract and its accessory organs receive about 25% to 30% of the cardiac output. Copyright © 2011, 2007 by Mosby, Inc., an affiliate of Elsevier Inc.

9 Circulatory system of the GI system Circulatory system of the GI system Portal vein : venous blood from the GI tract empties in to portal vein, which then perfuses the liver Splanchnic artery : upper portion of the GI tract receives blood from the splanchnic artery Small intestines receives its blood supply from branches of the hepatic and superior mesenteric arteries Large intestines receives its blood supply from the masenteric artery Copyright © 2011, 2007 by Mosby, Inc., an affiliate of Elsevier Inc.

10 Structures and Functions of Gastrointestinal System Copyright © 2011, 2007 by Mosby, Inc., an affiliate of Elsevier Inc. Fig Microscopic structure of liver lobule.

11 Structures and Functions of Gastrointestinal System Ingestion and Propulsion of Food Mouth Pharynx Esophagus Copyright © 2011, 2007 by Mosby, Inc., an affiliate of Elsevier Inc.

12 GI system Two types of movements of the GI tract : mixing ( segmentation ) and propulsion ( peristalsis ) The secretions of the GI system consists of enzymes and hormones for digestion, mucus for lubrication, and water and electrolytes. Copyright © 2011, 2007 by Mosby, Inc., an affiliate of Elsevier Inc.

13 Ingestion and propulsion of food Ingestion is the intake of food. Intake of food depends on the appetite Appetite center is located in the hypothalamus: stimulated by hypoglycemia, an empty stomach, decreased in body temperature, and input from higher brain centers. The sight, smell and taste of food usually stimulate appetite. Copyright © 2011, 2007 by Mosby, Inc., an affiliate of Elsevier Inc.

14 Ingestion cont.. Appetite may be inhibited by stomach distention, illness, hyperglycemia, nausea, vomiting and drugs( amphetamines). Deglutition or swallowing is the mechanical component of ingestion. ex mouth, pharynx, and esophagus Mouth: taste receptors( in the tongue), salivary glands ( parotid, submaxillary, and sublingual glands) Copyright © 2011, 2007 by Mosby, Inc., an affiliate of Elsevier Inc.

15 GI tract cont… Saliva : one liter of saliva is produced each day Saliva consists of water, protein, mucin, inorganic salts, and salivary amylase. Saliva: lubrication of food, and prevention of bacterial overgrowth Copyright © 2011, 2007 by Mosby, Inc., an affiliate of Elsevier Inc.

16 GI tract GI tract Esophagus : hollow muscular tube, moves food to stomach by peristalsis There are two sphincters : upper and lower esophageal sphincters ( upper in the proximal and lower in the distal end of the esophagus) LES remains contracted except during swallowing, belching and vomiting Copyright © 2011, 2007 by Mosby, Inc., an affiliate of Elsevier Inc.

17 Structures and Functions of Gastrointestinal System Copyright © 2011, 2007 by Mosby, Inc., an affiliate of Elsevier Inc. Fig Parts of the stomach.

18 Digestion and Absorption Mouth : digestion begins, mechanical and chemical digestion, amylase breaks starches to maltose Stomach: store and mix food with gastric secretions, only absorbs small amount of water, alcohol, electrolytes and drugs. LES and the pyloric sphincters guards the entrants and the exit from the stomach Secretions of stomach: pepsinogen which digests proteins, HCL activate pepsinogen to more active pepsin, lipase which digests fats and intrinsic factor promotes cobalamine ( vit B12) absorption in the small intestines. Copyright © 2011, 2007 by Mosby, Inc., an affiliate of Elsevier Inc.

19 S/P Gastractomy P atient at higher risk for vitamin B12 deficiency Copyright © 2011, 2007 by Mosby, Inc., an affiliate of Elsevier Inc.

20 Structures and Functions of Gastrointestinal System Copyright © 2011, 2007 by Mosby, Inc., an affiliate of Elsevier Inc. Fig Bilirubin metabolism and conjugation.

21 Digestion and Absorption Small intestines: two primary functions are digestion and absorption, extends from pylorus to the ileocecal valve, ileocecal valve prevents backing up from the large intestines Functional units of the small intestines are villi. They increase the surface area for absorption, secretes mucus and digestive enzymes. Secretions of the small intestines: enterokinase, amylase, peptidase, aminopeptidase, maltase, sucrase, lactase, and lipase Copyright © 2011, 2007 by Mosby, Inc., an affiliate of Elsevier Inc.

22 Digestion STOMACH: pepsinogen + HCL pepsin ( more active form ) + protein Amino acids There is minimal digestion of starches and fats in the stomach Small intestines: carbs into monosaccharides, fats to glycerol and fatty acids, and proteins to amino acids. Acidic nature of the chyme or the food that enters the duodenum is neutralized by pacreatic secretion of bicarbonate. Copyright © 2011, 2007 by Mosby, Inc., an affiliate of Elsevier Inc.

23 Digestion Cholesystokinin : produced by duodenum, contracts the gall bladder and relaxes the sphincter of odi which allows the bile to flow to the duodenum. Copyright © 2011, 2007 by Mosby, Inc., an affiliate of Elsevier Inc.

24 Elimination Large intestines: hollow, muscular tube about 5 to 6 feet long. Parts of large intestines: cecum and appendix, the colon, the rectum and anus Most important part of the large intestine is the absorption of water and electrolytes Nursing implications of colon resection and ileus: dehydration and electrolyte imbalance. Copyright © 2011, 2007 by Mosby, Inc., an affiliate of Elsevier Inc.

25 Structures and Functions of Gastrointestinal System Copyright © 2011, 2007 by Mosby, Inc., an affiliate of Elsevier Inc. Fig Anatomic locations of the large intestine.

26 Elimination Feces are composed of 75 % water, bacteria, minerals, and bile pigments. Bacteria in the colon also synthasize vitamine K and some of the B vitamins Defecation : reflex action, involuntary and voluntary, acceptable environment is usually necessary, if defecation is suppressed - constipation and impaction, defecation can be facilitated by valsalva maneuver. Copyright © 2011, 2007 by Mosby, Inc., an affiliate of Elsevier Inc.

27 Elimination cont.. Treatments for constipation : increase fluid intake, increase fiber, decrease laxative use, encourage defecation after eating breakfast as reflexes are most active after the first daily meal. And routine. Copyright © 2011, 2007 by Mosby, Inc., an affiliate of Elsevier Inc.

28 Elimination Constipation is common among older adults: slower peristalsis, inactivity, decreased dietary fiber, decreased fluid intake, depression and laxative abuse. Copyright © 2011, 2007 by Mosby, Inc., an affiliate of Elsevier Inc.

29 Liver, billiary tract and pancreas Liver : largest organ in the body and is located in the right epigastric region, blood supply by celiac artery and the portal vein, Function of the liver : manufacture, storage, transformation and excretion Excretion of bilirubin which is derived from the breakdown of hemoglobin Copyright © 2011, 2007 by Mosby, Inc., an affiliate of Elsevier Inc.

30 Structures and Functions of Gastrointestinal System Copyright © 2011, 2007 by Mosby, Inc., an affiliate of Elsevier Inc. Fig Gross structure of the liver, gallbladder, pancreas, and duct system.

31 Gerontologic considerations Effects of aging on the GI system Xerostomia : decreased saliva production, may associate with difficulty swallowing and dysphagia Taste buds decreased, sense of smell decreased and may lead to decreased appetite. Delayed emptying, and decreased HCL leads to infections Incompetent esophageal sphincter lead to GERD Copyright © 2011, 2007 by Mosby, Inc., an affiliate of Elsevier Inc.

32 Structures and Functions of Gastrointestinal System Copyright © 2011, 2007 by Mosby, Inc., an affiliate of Elsevier Inc. Table Phases of Gastric Secretion

33 Gerontologic Considerations: Effects of Aging on Gastrointestinal System Copyright © 2011, 2007 by Mosby, Inc., an affiliate of Elsevier Inc.

34 Diagnostic Studies of Gastrointestinal System Radiologic Studies Upper gastrointestinal series Lower gastrointestinal series Copyright © 2011, 2007 by Mosby, Inc., an affiliate of Elsevier Inc.

35 Diagnostic Studies of Gastrointestinal System Copyright © 2011, 2007 by Mosby, Inc., an affiliate of Elsevier Inc. Fig Barium enema x-ray showing the large intestine.

36 Diagnostic Studies of Gastrointestinal System Copyright © 2011, 2007 by Mosby, Inc., an affiliate of Elsevier Inc. Fig Ultrasound of gallbladder showing multiple gallstones.

37 Diagnostic Studies of Gastrointestinal System Radiologic Studies, continued Virtual colonoscopy Endoscopy ( EGD) These studies require patients to be on golytely to clear bowels Copyright © 2011, 2007 by Mosby, Inc., an affiliate of Elsevier Inc.

38 Diagnostic Studies of Gastrointestinal System Copyright © 2011, 2007 by Mosby, Inc., an affiliate of Elsevier Inc. Fig Ileocecal junction. A, Illustration showing the ileocecal junction and the ileocecal fold. B, Endoscopic image of the ileocecal fold.

39 Diagnostic Studies of Gastrointestinal System Copyright © 2011, 2007 by Mosby, Inc., an affiliate of Elsevier Inc. Fig Capsule endoscopy. A, The video capsule has its own camera and light source. After it is swallowed, it travels through the GI tract and allows visualization of the small intestine. It sends messages to a monitoring device that is worn on a waist belt (B). During the 8-hour examination, the patient is free to move about. After the test, the images are viewed on a video monitor.

40 Diagnostic Studies of Gastrointestinal System Liver Biopsy ; patient is place on the right side to prevent bleeding. Liver Function Studies Copyright © 2011, 2007 by Mosby, Inc., an affiliate of Elsevier Inc.