HA 12 - GIT

• Gastrointestinal System


  A hollow tube that begins at the mouth and ends at the anus, 7.5 cm long, consists of smooth muscles alternating with blood vessels and nerve tissue, with specialized circular and longitudinal fibers that contract and cause peristalsis to aid in propelling food through the GIT
• Stomach


  • Dilated sac-like structure, lies obliquely in the LUQ, has a Cardiac Sphincter that protects the entrance and a Pyloric Sphincter that guards the exit, stores food and mixes it with gastric juices like mucus, pepsin, and hydrochloric acid, secretes intrinsic factor that protects Vitamin B12 and facilitates its absorption, passes chyme into the small intestine for further digestion and absorption
• Small Intestine


  • Primary site for digestion, absorbs essential nutrients into the bloodstream, consists of the
  • Duodenum (10 in)(where bile and pancreatic secretions are added to the chyme)
  • Jejunum (8 in) (responsible for breakdown and absorption of most nutrients),
  • Ileum (12 ft long)

  
• Appendix


  • Found at the ileocecal junction, unknown function, narrowest part of intestines, frequent site for bacteria and indigestible matter to become trapped leading to inflammation (appendicitis),
  • may serve as a breeding ground for intestinal bacteria because it contains large amount of lymphatic tissue
• Large Intestine


  • 5 to 6 ft long, absorbs salt and water, excretes waste products of digestive process (feces) from the rectum, helps synthesize Vitamin B12 and K
  • consists of the Cecum, Ascending, Transverse, Descending, Sigmoid colon, Rectum, and Anus
• Accessory GI Organs

  • Salivary Glands
  • Liver
  • Gallbladder
  • Bile Ducts
  • Pancreas
  • Urinary Tract
• Salivary Glands


  • Produce saliva that moistens and lubricates food, secrete amylase which converts starches to maltose, include the Parotid, Submandibular, and Sublingual glands
• Liver


  • Metabolizes carbohydrates, fats, proteins, detoxifies blood substances, converts glucose to glycogen, converts ammonia to urea, produces plasma proteins, stores vitamins and minerals, secretes bile
• Gallbladder


  • Stores and concentrates bile produced by the liver
• Bile Ducts


  • Transport bile from the liver to the gallbladder and small intestine
• Pancreas


  • 6 to 8 inches long, consists of the head, body, and tail, contains beta cells that release insulin, alpha cells that secrete glucagon, delta cells that secrete somatostatin, and F cells that secrete pancreatic polypeptide
• Urinary Tract


  • Maintains homeostasis of fluid, electrolyte, and acid-base system, controls blood pressure through secretion of renin, secretes erythropoietin to stimulate red blood cell production, removes waste products from the body
• Shapes of Abdomen

  • Average adult (flat round, scaphoid)
  • Flat (muscular patients)
  • Round (normal in infants & toddlers, poor muscle tone, excess fat in adults)
  • Scaphoid/concave (thin patients)
  • Protuberant
• Deglutition (swallowing)


  Involves the Integumentary and Musculoskeletal systems to protect and support the GI tract, and assist with ingestion, mastication, and defecation
• Respiratory and Cardiovascular systems

  Provide the oxygen needed for the digestive organs to function, any decrease in oxygen affects organ function (e.g. bowel infarct from disrupted blood flow)
• Neurologic system


  Parasympathetic response ("rest & repair") stimulates secretion of digestive juices and increases peristalsis via acetylcholine, while sympathetic response (stress) decreases peristalsis and secretion via norepinephrine
• Endocrine system

  The pancreas has both endocrine (insulin, glucagon, gastrin) and exocrine (bicarbonate, enzymes) functions that assist in carbohydrate metabolism and digestion
• Developmental Variations

  • Infants: Bladder located above symphysis pubis, larger liver, weak abdominal muscles

  Children: Proportionately larger abdomen, protuberant appearance, common abdominal respiration

  Pregnant Women: Abdominal muscles relax, diastasis recti abdominis, diminished bowel sounds, constipation, hemorrhoids, appendix displaced

  Older Adults: Reduced dentition, saliva, stomach acid, gastric motility and peristalsis, constipation, fat accumulation, smaller liver with declining function
• Cultural Variations

  • African Americans: Sickle cell anemia, lactose intolerance

  Asian-Americans: GI cancer

  Ashkenazi Jews: Colon cancer

  Native Americans: Alcoholism, liver disease, pancreatitis, diabetes, gallbladder disease
• Abdominal Pain


  • Most common complaint
• Gastric motility

  • Peristalsis
• Problems with gastric motility

  Problems in swallowing, absorption & digestion
• Constipation


  • General reduction of muscle mass & tone
• Fat accumulation


  • Women (lower abdomen); Men (waist)
• Liver


  • Smaller & function declines
• Cultural variations

  • African Americans (sickle cell anemia, lactose intolerance)
  • Asian-Americans (GI cancer)
  • Ashkenazi Jews (colon cancer)
  • Native Americans (alcoholism, liver disease, pancreatitis, diabetes, gallbladder disease)
• Abdominal pain


  The most common complaint
• Visceral pain


  Results from distention of the intestines or stretching of the solid organs, often described as burning, cramping, diffuse & poorly localized
• Parietal pain


  Results from inflammation of the parietal peritoneum, pain is severe, localized & aggravated by movement
• Referred pain


  Is felt at a site away from the site of origin
• Acute abdominal pain


  May indicate life threatening abdominal condition that requires immediate medical attention
• Pain location

  • Umbilical region (abdominal aortic aneurysm, early appendicitis)
  • Chest (referred abdominal pain, chest pain can either be abdominal or cardiac)
  • Epigastric (left of midline) (gastric ulcer, angina/MI)
  • Radiates back, neck, jaw (GERD, mimics MI)
  • Shoulder (ruptured spleen, ectopic pregnancy, pancreatitis)
  • Scapulae (cholelithiasis, MI, angina, biliary colic, pancreatitis)
  • Thighs, genitals, lower back (renal problem, ureteral colic)
  • Lower & middle back (abdominal aortic aneurysm)

  
• Duodenal ulcer


  Pain can be relieved by eating, bleeding in the stool called melena
• Gastric ulcer


  Pain occurs 1-2 hours after eating, there is blood when the patient vomits called hematemesis
• Abdominal quadrant pain

  • RUQ (MI/ischemia, pneumonia, cholelithiasis, cholecystitis, hepatitis, cancer, duodenal ulcer)
  • RLQ (ovary/uterus, perforation, obstruction, constipation, Crohn's disease, diverticulitis, hernia, ulcerative colitis, appendicitis, kidney)
  • LUQ (MI/ischemia, pulmonary embolism, pneumonia, pancreatitis, ruptured spleen, gastric ulcer, esophagitis, GERD, hiatal hernia, varices)
  • LLQ (ovary/uterus, perforation, constipation, diverticulitis, hernia, ulcerative colitis, kidney)
• Weight change


  May indicate diseases of many body systems, major depressive disorders, eating disorders, unexplained weight loss in adults raises suspicions of malignancy
• Change in bowel pattern


  Establish baseline, stool color (black/tarry - upper GI bleeding, red/bloody - lower GI, clay colored - obstructive jaundice), constipation, diarrhea
• Dyspepsia/Pyrosis


  Usually described as "heartburn", burning sensation usually worst after a meal, acid from stomach flows into lower esophagus
• GERD


  Gastroesophageal reflux disease, heartburn as chief symptom
• Nausea


  Stress on the stomach wall or esophagus, distention, alteration in peristalsis, negative olfactory stimulation, inner ear problem, medications