Exam 4- Gastrointestinal Flashcards
Hepatocytes
Metabolize nutrients, detoxify chemicals, secrete bile, synthesize albumin and clotting factors, and other functions.
Synthesize the primary bile acids from cholesterol.
Kupffer cells
Remove bacteria and foreign particles from blood in the hepatic sinusoids.
Pancreatic acinar cells
Secrete digestive enzymes.
Bile
Produced in liver. Slightly alkaline. Secreted by hepatocytes into the canaliculi, which empty into the bile ducts.
Choleretic agent stimulates liver to release bile.
Peristalsis
Waves of sequential relaxations and contractions of the gastrointestinal muscles.
Caused by stretching of the esophagus or intestine by bolus of food.
Gastric emptying
Delayed by fatty foods and hypertonic gastric contents. And cholecystokinin.
Stimulated by gastrin.
Intestinal brush border
Collection of microvilli.
Enzymes in the border hydrolyze oligopeptides.
Small intestine
Supplied primarily by the superior mesenteric artery.
The 3 segments are the duodenum, jejunum, and ileum.
Absorbs most of the water that enters the gi tract.
Sugars absorbed primarily in the initial portions.
Pancreatic proteases
Secretes in inactive form.
Pancreatic amylases
Secreted in active form. Digests carbohydrates.
Gastrointestinal changes with age
Gastrointestinal motility tends to decrease.
Liver blood flow and enzyme activity decrease.
LFTs remain normal in an older adult without overt liver disease.
Gastric acid
Increased by histamine, gastrin, vagal stimulation, and caffeine.
Decreased by cholecystokinin and sympathetic stimulation.
Esophagus
Upper 1/3 has striated muscle.
Lower 1/3 had smooth muscle.
Peritoneum
Visceral layer covers the abdominal organs.
Parietal layer extends along the abdominal wall.
Pepsin
Gastric enzyme that digests proteins.
Only functions in an acidic environment.
Celiac artery
Supply most of the blood to the stomach.
Superior mesenteric artery
Provides most of the circulation to the small intestine.
Villi
The functional units of the intestine.
Each one has a capillary at the center known as the lacteal, which is important in absorption of fat molecules.
Excretion in the intestines happen at the tops of the villi.
Round ligament
Remnant of the umbilical vein.
Enteric nervous system
Lies within the gastrointestinal tract and consists of neurons of the submucosal plexus, the myenteric plexus, and the subserosal plexus.
Pyloric valve
Valve between the stomach and duodenum.
Chief cells
Gastric cells that secrete pesinogin
Parietal cells
Gastric cells that secrete hydrochloric acid.
Cephalic phase
Phase of gastric acid secretion acid secretion involving anticipation and swallowing.
Sphincter of Oddi
Sphincter through which bile enters the intestine.
GERD
Reflux of acid and pepsin from the stomach to the esophagus that causes esophagitis.
Decreased resting tone of the lower esophageal sphincter. Symptoms include heartburn and chronic cough.
Acute mesenteric ischemia
The damaged intestinal mucosal I cannot produce enough mucus to protect itself from digestive enzymes. Bacteria invade the necrotic intestinal wall, eventually causing peritonitis.