The Gastrointestinal System Flashcards
(152 cards)
What are the four main components of the digestive system?
- GI tract
- Pancreas, gall bladder, liver
- Enzymes, hormones, nerves, blood
- Mesentery – tissue that supports digestive organs
Outline the process of digestion
- saliva produced in response to food
- churning and mixing with saliva turns food into bolus.
- Saliva breaks down starch/sugar.
- bolus passes through esophagus to the stomach.
- Stomach nerves sense food and trigger peristalsis.
- Stomach mixes and churns bolus with acid and enzymes that break down proteins. This stimulates the pancreas, liver, and gallbladder to produce digestive juices. Bile secreted by the gallbladder.
- bolus moves into small intestine, where bile is secreted by the gall bladder.
- The duodenum dissolves fats to be digested by pancreatic juices and bile. Carbs get converted into glucose, fats to triglycerides and fatty acids, and proteins into amino acids.
- Enzymes are absorbed into the ilium
- water, fibre, and waste move into the colon and body signals defecation.
Total Parenteral Nutrition
nutrition delivered intravenously
- contains dextrose, amino acids, electrolytes
Indications: enteral nutrition is contraindicated or the patient is unable to tolerate; increased aspiration risk; GI obstruction
Complications: infection (change bag and tubing q24h; refrigerate until hanging bag), fluid overload (daily weights; check lytes), hyper/hypoglycemia (don’t stop abruptly; give 10% dextrose if bag runs out; titrate when turning up or down; check BG q4-6h); embolism.
Laxatives
Action: Produce immediate BM
Examples: Lactulose, bisacodyl, milk of magnesia, PEG, Senna
Stool Softeners
Action: pulls water into the GI tract
Example: Docusate
Antidiarrheals
Loperamide
Diphenoxylate
Bismuth
Antiemetics: Ondansteron
Indication: nausea, vomiting
Action: blocks effects of serotonin on the vagal nerve and CNS
Considerations: administer slowly; fast IV push can cause prolongation of QT interval and ventricular tachycardia.
Antiulcer Agents
H2 Receptor Blockers
PPIs
Antacids
GI protectants
Famotidine
Pharm Class: H2 Receptor Blocker
Action: blocks release of histamine and gastric acid secretion
indication: GERD; hypersecretory conditions; GI distress
Considerations: monitor kidney function and CBC; use short term.
Omeprazole
Pharm Class: PPI
Indications: GERD and ulcers
Action: Prevents H+ transport into gastric lumen; decreases gastric acid secretion production.
Considerations: administer 30-60 mins before meals; report black, tarry stools ( ulceration may cause bleeding).
Sucralfate
Indication: Ulcers; GERD
Action: promotes healing by providing a barrier and binding to proteins excreted by damaged ulceration tissue.
Considerations: avoid antibiotics for 2 hours; may decrease bioavailability of warfarin, digoxin, phenytoin, and levothyroxine; take on empty stomach; avoid antacids within 30 mins; caution with renal failure; monitor BG in diabetics.
Nasogastric Tube
tube inserted into the nare that terminates in the stomach
Indication: enteral nutrition, decompression, med amin, removal of stomach contents following overdose.
How is placement for NG tube verified?
chest x-ray
May also test residuals for pH (If residuals more than 500mL, hold the feed)
Blakemore tube
tube inserted into the esophagus to the stomach that balloons to stop bleeding along the esophagus
Considerations: keep scissors at bedside.
Function of the small intestine
absorbs nutrients
churns and mixes digested foods with mucous and enzymes, creating chyme; receives digestive juices from pancreas and liver.
Function of the large intestine
absorbs H20 and electrolytes; produces and absorbs vitamins; forms and propels feces towards the rectum
Ulcerative Colitis
inflammation of the large intestines, producing ulcerated surfaces that appear to be patchy
Crohn’s Disease
Inflammation and erosion of the ileum and anywhere else throughout the small intestine and large intestine.
Treatment for Crohn’s
LOW Fibre diet*
avoid hot/cold foods
steroids
no smoking
antidiarrheals
antibiotics
severe cases may involve removing portion of intestine with ostomy for relief.
Appendicitis
inflammation of the appendix
Signs and Symptoms of Appendicitis
pain begins with full, steady periumbilical pain
over 4-6 hrs, pain progresses and localizes to RLQ pain
nausea, vomiting
increased temperature
anorexia
increased WBC
Sudden relief may indicate burst appendix, which can lead to peritonitis
McBurney’s Sign (rebound tenderness of RLQ)
Pre-op positioning for appendectomy
no heat (induces rupture)
right-sided fowlers
Post-op Appendectomy Care
IV ABx
Pain management
NPO until return of bowel sounds
wound care
Endocrine Function of the pancreas
regulates blood glucose by releasing insulin and glucagon