Exam 4 Flashcards
What cells secrete hydrochloric acid and intrinsic factor, gastroferrin?
Parietal cells
Parietal cells also secrete intrinsic factor and gastroferrin.
What cells secrete pepsinogen?
Chief cells
Chief cells secrete pepsinogen which is then converted to pepsin in the presence of acid.
What cells secrete gastrin?
G cells
G cells secrete gastrin which stimulates hydrochloric acid secretion.
What cells secrete histamine?
Enterochromaffin-like cells
Enterochromaffin-like cells secrete histamine which stimulates hydrochloric acid secretion.
What cells secrete somatostatin?
D cells
D cells secrete somatostatin which inhibits hydrochloric acid secretion.
What is the function of the small intestine?
Includes duodenum, jejunum, and ileum where most absorption occurs
Villi are the functional units of the intestine where absorption occurs.
What is the function of the large intestine?
Includes cecum, appendix, colon, rectum, anus
The large intestine absorbs water and electrolytes and has goblet cells but no villi for absorption.
What is the function of the liver?
Largest solid organ; synthesizes bile, stores blood, metabolizes carbs, makes toxins less harmful, and stores minerals and vitamins
Hepatocytes are the functional unit of the liver.
What is the function of the gallbladder?
Stores and concentrates bile between meals
The gallbladder forces bile to flow into the duodenum through the sphincter of Oddi.
What is the function of bile?
Alkaline fluid necessary for fat digestion and absorption
Bile salts are required for the emulsification and absorption of fats.
What is bilirubin?
Pigment by-product of aged red blood cell destruction in the liver and spleen
Unconjugated bilirubin is lipid soluble and present in circulation bound to protein.
What is unconjugated bilirubin?
lipid soluble and can cross cell membrane, present in circulation bound to protein
Produces yellow tinge in jaundice.
What is conjugated bilirubin?
combined with a sugar to water soluble by the liver so it can be excreted in the bile.
What does a high percentage of unconjugated bilirubin indicate?
heme breakdown (hemolytic anemia) or inability of the liver to conjugate
What does a high percentage of conjugated bilirubin indicate?
there is a problem with the secretion into bile like hepatitis, or obstruction.
What is anorexia?
lack of desire to eat, non specific symptom
What is vomiting?
forceful emptying of the stomach and intestinal contents. Can cause metabolic consequences like hyponatremia, hypokalemia, hypochloremia, and metabolic alkalosis.
What is constipation?
infrequent or difficult defecation
-Normal transit: normal rate but difficulty from low residue, low fluid diet
-Slow transit: impaired colonic motor activity, infrequent BMs and straining
- Pelvic floor dysfunction: failure of the pelvic floor muscles or sphincter to relax
What is diarrhea?
increased frequency or increased volume, fluidity, or weight. Can lead to dehydration, electrolyte imbalance, metabolic acidosis, and weight loss
-Large volume: caused by excessive amounts of water or secretions
-osmotic: nonabsorbable substance in the intestine draws water into the lumen by osmosis
-secretory: caused by excessive mucosal secretion of chloride or bicarb-rich fluid -Small volume: caused by increased intestinal motility
-motility: excessive motility decreases transit time, mucosal surface contact, and opportunities for fluid absorption
What is the basic pathophysiology of abdominal pain?
stretching, inflammation, or ischemia
What are the types of abdominal pain?
Parietal: in the peritoneum (localized and intense)
Visceral: in the organs themselves
RUQ: liver, gall bladder, bile duct
RLQ: appendix, right ovary/fallopian tube
LUQ: stomach, spleen
LLQ: descending colon, left ovary/fallopian tube
What is melena?
black, tarry stools; upper GI bleed, Pepto-Bismol or iron intake
What is dysphagia?
Difficulty swallowing can result from a mechanical or functional disorder.
-Mechanical:
-intrinsic: obstructions that originate in the wall of the esophageal lumen (tumors, strictures, diverticular herniations)
-extrinsic: originate outside the esophageal lumen and narrow the esophagus by pressing inward (tumor) Functional:
-caused by neural or muscular disorders that interfere with voluntary swallowing (CVA, PD)
What is GERD?
Acid and pepsin refluxes from the stomach into the esophagus, causing esophagitis.
- Resting tone of LES tends to be lower than normal from either transient relaxation or weakness of the sphincter
-Vomiting, coughing, lifting, bending, or obesity can contribute to GERD
-Physiologic reflux: does not cause symptoms; acid is neutralized and clears in 1-
3 minutes and LES tone is restored
-NERD: symptoms but no visible mucosal injury
-Reflux esophagitis: injury and inflammation
-Manifestations: heartburn within 1 hour of eating, s/s worsen with lying down or increased intra-abdominal pressure
Pyloric obstruction
The blocking or narrowing of the opening between the stomach and the duodenum Manifestations: epigastric pain, succession splash, vomiting that is copious and occurs several hours after eating (cardinal sign),
