Chapter Seventeen
Function of the Digestive System:
• Digestion and absorption
o Carbohydrates, protein and lipid
o Fat soluble vitamins
▪ A,D,E,K - absorbed with fats
o Water soluble vitamins
▪ B and C - diff
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Chapter Seventeen
Function of the Digestive System:
• Digestion and absorption
o Carbohydrates, protein and lipid
o Fat soluble vitamins
▪ A,D,E,K - absorbed with fats
o Water soluble vitamins
▪ B and C - diffuse into blood
o Electrolytes
o Drugs are primarily absorbed in the intestine
o Water
▪ Absorbed primarily by osmosis
▪ Severe vomiting or diarrhea will interrupt this recycling mechanism
▪ Affects fluid and electrolyte balance of body
Common Manifestations:
• Anorexia, nausea, vomiting, bulimia
• Diarrhea or constipation
• Blood in stool
o Frank blood
▪ Red blood - usually from lesions in rectum or anal canal
o Occult blood
▪ Small hidden amounts
▪ Detectable with stool test
o Melena
▪ Dark-colored, tarry stool
• Gas
• Fluid and electrolyte imbalances
o Dehydration and hypovolemia are common complications of GI disorders
o Electrolytes are lost in vomiting and diarrhea
• Acid-base imbalances
o Metabolic alkalosis
▪ Loss of HCL acid with vomiting
o Metabolic acidosis
▪ Severe vomiting causes a change to metabolic acidosis because of the loss of bicarbonate of duodenal secretions
▪ Diarrhea causes a loss of bicarbonate
• Pain
• Malnutrtion
Dysphagia:
• Difficulty swallowing
Causes of Dysphagia:
• Neurological deficit
o Stroke, brain damage, achalasia
• Muscular disorder
o Impairment from muscular dystrophy
• Mechanical obstruction
o Congenital atresia
▪ Developmental anomaly
o Stenosis
▪ Narrowing of the esophagus
▪ May be secondary to fibrosis, chronic inflammation, ulceration, radiation or scar tissue
o Esophageal diverticula
o Tumors
Hiatal Hernia:
• Part of the stomach protrudes into the thoracic cavity
Sliding Hernia:
• Portions of the stomach and gastroesophageal junction slide up above the diaphragm
Rolling or Paraesophageal Hernia:
• Part of the fundus of the stomach moves up through an enlarged or weak hiatus in the diaphragm and may become trapped
Signs and Symptoms of Hiatal Hernia:
• Heartburn or belching
• Increased discomfort when lying down after eating, bending over or coughing
Gastroesophageal Reflux Disease:
• Periodic reflux of gastric contents into distal esophagus causes erosion and inflammation
• Decrease lower esophageal sphincter (LES) or increase intra-abdominal pressure allows more of the gastric contents to reflux back into the esophagus
• Severity depends on competence of the lower esophageal sphincter
• Factor reduce LEs
o Caffeine, fatty and spicy foods, alcohol, smoking, certain drugs
• Heartburn frequently occurs 30 to 60 minutes after eating or at night
Acute Gastritis:
• Gastric mucosa is inflamed, may be ulcerated and bleeding
Etiology of Acute Gastritis:
• Infection by microorganisms
• Chemical substances: NSAIDS, alcohol, etc…
Effects of Acute Gastritis:
• Basic signs of gastrointestinal irritation
• Anorexia, nausea, vomiting, epigastric pain, cramps or general discomfort
• Hematemesis caused by bleeding
• With infection, diarrhea may develop
Chronic Gastritis:
• Atrophy of stomach mucosa
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