Gastroenterology Flashcards
Gastrin
Secreted by G-cells (antrum), stimulates parietal cells in fundus
Cholecystokinin
Secreted by I-cells (duodenum), contracts gallbladder and plrolongs gastric emptying time
Secretin
Secreted by S cells (duodenum), inhibits acid secretion
Glucose-dependent Insulinotropic Peptide
Secreted by K cells (duodenum), stimulates insulin secretion
Gastrin, Histamine, Acetylcholine
Stimulate gastric acid secretion (synergistic effect)
Motilin
Stimulates motility during fasting
Mucus Neck Cells
Secretes mucus in the stomach
Parietal Cells
Secretes HCl and intrinsic factor in the stomach
Chief Cells
Secretes pepsinogen in the stomach
Enterochromaffin cells
Secretes serotonin in the stomach
Enterochromaffin-like cells
Secretes histamine in the stomach
Interstitial cells of Cajal
Pacemaker cells of the GI that generates slow waves
Liver Acinus Model (Zones 1-3)
Preferred functional unit of the liver
Ito Cells
Stores Vitamin A in the liver
Enterokinase
Intestinal enzyme that triggers conversion of pancreatic trypsinogen to trypsin
Enterohepatic circulation
Main mechanism for bile salt reabsorption
Triglyceride Absorption
Lumer -> intestinal cells as micelles –> lacteals as chylomicrons
Mouth (salivary amylase/ptyalin)
Initial digestion of carbohydrates
Stomach (lingual lipase)
Initial digestion of fats
Stomach (pepsin and HCl denaturation)
Initial digestion of proteins
Duodenum
For iron and vitamin C absorption
Jejunum
Main site for Carbohydrates, fats, proteins, water absorption
Ileum
Main site for vitamin B12, IF, bile salts and vitamins ADEK absorption
Rule of 2’s in Meckel’s diverticulum
2% of population, 2 years old, 2:1 male to female ratio, 2 tissue types involved, 2 inches long, 2 feet from Ileocecal valve
Diagnostic Criteria for Irritable Bowel Syndrome
Recurrent abdominal pain or discomfort for at least 3 days per month in the last 3 months associated with 2 or more of the following: improvement with defecations, onset associated with a change in frequency of stool, onset associated with a change in appearance of stool
Charcot’s Triad for Ascending Cholangitis
Fever, Abdominal Pain, Jaundice
Charcot’s Triad for Multiple Sclerosis
Scanning speech, intention tremor, nystagmus
Reynold’s Pentad
Charcot’s Cholangitis Triad + Shock and confusion
Triad of Hepatopulmonary Syndrome
Liver disease, Hypoxemia, Pulmonary arteriovenous shunting
Triad of Acute Cholecystitis
Sudden RUQ tenderness, fever, leukocytosis
Triad of Choledochal Cyst
Abdominal pain, jaundice, abdominal mass
Triad of Hemobilia
Biliary Pain, Obstructive Jaundice, Melena
Diagnosis of Acute Pancreatitis
Typical abdominal pain, 3x or grater elevation in serum amylase and/or lipase levels, Confirmatory findings on cross-sectional abdominal imaging
Pseudocyst
Increase in size of the mass, a localized bruit over the mass, sudden decrease in hemoglobin and hematocrit without external blood loss
Classic Symptoms of GERD
Water brash and substernal heart burn
Gastroesophageal reflux
Most common cause of esophageal chest pain
24-hour ambulatory pH monitoring
Most sensitive test for diagnosis of GERD
Globus hystericus
Perception of a lump or fullness in the throat that is felt irrespective of swallowing
Odynophagia
Characteristic symptom of infectious esophagitis
Schatzki ring in the lower esophagus
Common cause of steakhouse syndrome
Bird’s beak appearance
Radiographic sign in achalasia
Corkscrew or rosary bead esophagus
Seen radiographically in diffuse esophageal spasm or spastic achalasia
Esophageal manometry
Detects impaired LES relaxation and absent peristalsis in achalasia
Endoscopy or esophagogastroduodenoscopy
Best test for evaluation of proximal GIT
Crohn’s disease
Cobblestone appearance of esophagus
Endoscopic biopsy
Gold standard for confirmation of Barrett’s esophagus
Typical presentation of esophageal cancer
Progressive solid food dysphagia and weight loss
Squamous cell CA
Middle third of the esophagus, associated with smoking
Adenocarcinoma
Distal third of the esophagus, associated with GERD and Barrett’s esophagus (metaplasia from squamous to columnar epithelium)
Peptic ulcers
Most common cause of UGIB
Hemorrhoids
Most common cause of LGIB overall
Anal fissure
Most common cause of rectal bleeding during infancy
Meckel’s diverticulum
Most common cause of significant LGIB in children
BD and juvenile polyps
Most common colonic causes of significant GIB in children and adolescents
Hemorrhage from a colonic diverticulum
Most common cause of hematochezia in the elderly
Small intestinal sources of bleeding
Majority of obscure GIB
Boerhaave Syndrome
Full-thickness esophageal tear
Mallory-Weiss Tear
Partial-thickness esophageal tear
Classic history of Mallory-Weiss Tear
Vomiting, retching, coughing, hematemesis in an alcoholic/bulimic patient
NSAID, alcohol, stress
Most important causes of Hemorrhagic and erosive gastropathy
Heart rate and BP
Best way to initially assess a person with GIB
Upper endoscopy
Procedure of choice in UGIB
Colonoscopy after an oral lavage solution
Procedure of choice in LGIB
Angiography
Initial test for massive obscure GIB
Key enzyme in rate-limiting step of prostaglandin synthesis
Cyclooxygenase
Most common causes of gastric/duodenal ulcers
H. pylori and NSAU+Iss
Most common location of GU’s
1st portion of duodenum
Most discrimating symptom of Dus
Pain that awakens the patient from sleep
Most frequent finding in patients with GU/DU
Epigastric tenderness
PUD-related complications
GI bleeding > perforation > gastric outlet obstruction (in order of decreasing frequency)
Most potent acid inhibitory agents
Proton pump inhibitors
Most common toxicity with sucralfate
Constipation
Most common toxicity with prostaglandin analogs
Diarrhea
Most feared complication with amoxicillin, clindamycin
Pseudomembranous colitis
GU: failure to heal after 12 weeks of therapy, DU: failure to heal after 8 weeks of therapy
Refractory Peptic Ulcers
Most common cause of treatment failure in compliant patients
Antibiotic-resistant H. pylor strains
Test of choice for documenting eradication of H. pylori
Urea breath test
Most commonly performed operations for DU’s
Vagotomy and drainage, highly selective vagotomy, vagotomy with antrectomy
High ulcer recurrence rate but lowest complication rate
Highly selective vagotomy
Lowest ulcer recurrence rate but highest complication rate
Vagotomy with antrectomy