bananas's version from 2015-07-08 20:36


Question Answer
Secreted by G cells (Antrum, Duodenum)Gastrin
Secreted by Parietal cellsIntrinsic Factor (IF) and Gastric acid
Secreted by Chief cellsPepsin
Secreted by Mucosal cellsHCO3-
Secreted by D cells (Pancreas, GI mucosa)Somatostatin
Secreted by I cells (duodenum and jejunum)Cholecystokinin (CCK)
Secreted by S cells (duodenum)Secretin
Secreted by K cells (duodenum)GIP
Secreted in the Small intestineMotilin
Parasympathetic gangliaVIP
Gastrin↑ H+ secretion
↑Gastric motility
IFBinds B12 to help it be reabsorbed in the ileum
PepsinProtein digestion
HCO3-Neutralizes acid in the stomach, duodenum (brunner glands), pancreas
SomatostatinUniversal inhibitor!
Cholecystokinin↑Pancreatic secretion
↑GB contraction!!
Relaxes sphincter of oddi
Slows gastric emptying
Secretin↑Pancreatic HCO3-
↑Bile secretion
Inhibits gastric acid
GIPExocrine: ↓Gastric H+
Endocrine: ↑Insulin
VIP↑Water and electrolyte secretion
↑Relaxation of intestinal SM
NORElaxes SM and LES
Stimulated by stomach distentionGastrin
Increased by acidSomatostatin
Increase by FACCK, Secretin, GIP
Stimulated by HIstamine, ACh and gastrinParietal cells releasing gastric acid!
Stimulated by vagusPepsin and Gastric acid


Question Answer
Gastroschisisextrusion of abdominal contents, not covered
Omphaloceleextrusion of abdominal contents, covered by peritoneum
Failure of rostral fold closuresternal defects
Failure of lateral fold closureOmphalocele
Failure of caudal fold closurebladder exstrophy
Duodenal atresia (failure to recanalize)Trisomy 21
Jejunal, ileal, colonic atresiad/t vascular accident (apple peel atresia)
Esophageal atresia with distal tracheoesophageal fistulamost common cause of EA (85%)
Drooling, choking, vomiting with first feeding
TEF allows air into the stomach → visible on CXR
failure to pass NG tube into stomach
H-type esophageal atresiaPure TEF
Pure EA does not show...gas in abdomen on CXR
Describe the anatomy of the MC type of esophageal fistulablind upper esophagus with the lower esophagus attached to the trachea
"olive mass"congenital pyloric stenosis
Non bilious projectile vomiting 2-6 wks oldcongenital pyloric stenosis
Failure of dorsal and ventral pancreas to fusepancreas divisum (asymptomatic)
Bilious vomitingAnnular pancreas
Intestinal obstruction
Meconium ileus
Ring of pancreatic tissue around the 2nd part of the duodenumAnnular pancreas
Malrotation of the midgut around the SMAMidgut volvulus, Intestinal obstruction
Pancreas is derived from [?]Foregut aka endoderm
What is weird about the blood supply to the Spleen?Derived from stomach mesentary aka mesoderm but is supplied by celiac artery from the foregut
Which GI malformations are associated with Down's syndrome?Duodenal atresia
Hirschsprung Disease
Annular pancreas
Celiac disease
Which abnormalities are associated with Annular pancreas?Polyhydramnios
Duodenal atresia
Imperforate anus
Meckel's diverticulum
Midgut rotation around SMA
Failure of the vitilline duct (omphalomesenteric duct) to obliterateMeckel diverticulum
Abnormal migration of ventral pancreatic bud to fuse with dorsal bud from 2 sidesAnnular pancreas
Retroperitoneal structures (mnemonic)SAD PUCKER
Suprarenal gland (adrenal)
Aorta and IVC
Duodenum (2nd and 3rd parts only)
Pancreas (except tail)
Colon (descending and ascending only)
Esophagus (lower 2/3rds)
Rectum (lower 2/3rds)


Question Answer
Common causes of Acute gastritis?ABC's
A: Alcohol, NSAIDs
B/C: Burn causes Curling
B/C: Brain injury causes Cushing
Inflammation of mucosal barrierAcute gastritis
Autoimmune destruction of parietal cellsChronic gastritis type A
Type IV HypersensitivityChronic gastritis type A
AchlorhydriaChronic gastritis type A
Pernicious anemiaChronic gastritis type A (due to lack of intrinsic factor to help B12 absorption)
Inflammation of Fundus/BodyChronic gastritis type A
MC type of Chronic gastritisChronic gastritis type B
Caused by H. pyloriChronic gastritis type B
[B for Bacteria]
Increased risk of MALT lymphomaChronic gastritis type B


Question Answer
Increase pain with mealsGastric ulcer
Decrease pain with mealsDuodenal ulcer
H pylori sometimesGastric ulcer
H pylori 100%Duodenal ulcer
Caused by NSAIDsGastric ulcer
Zollinger Ellison gastrinomaDuodenal ulcer
Increases risk of carcinomaGastric ulcer
BenignDuodenal ulcer
Hypertrophied Brunner glandsDuodenal ulcer
Free air under the diaphragmGastric ulcer perforation
Treatment of ulcersSomatostatin (Octreotide)


Question Answer
Risks associated with Celiac sprue?Malignancy: T-cell lymphoma, GI and breast cancer
HLA associated with Celiac sprue?HLA-DQ2 and HLA-DQ8
Antibodies found in celiac sprueAnti-tissue transglutaminase
Blunting of villi
Crypt hyperplasia
Celiac Sprue: SI Biopsy is necessary to diagnose
Which part of the GI tract is affected in Celiac sprue?Distal duodenum, Proximal Jejunum
Mechanism of Celiac sprue?Autoimmune intolerance of gliadin
MC Disaccharidase deficiencyLactase deficiency
Dx lactase deficiencyAdministration of Lactose produces symptoms
Serum glucose rises <20mg/dL
What kind of diarrhea do you get with lactase deficiency?Osmotic
Common causes of pancreatic insufficiencyCystic Fibrosis
Obstructing cancer
Chronic pancreatitis
Mechanism of steatorrhea with pancreatic insufficiencyNo lipase, can't digest fats
D-xylose test results with pancreatic insufficiencyNormal urinary excretion (Problem is not surface)
Celiac sprue that doesn't improve with decreased glutenTropical sprue
Recent tropicsTropical sprue
PAS+Foamy macrophages in intestinal lamina propria Whipple disease
Symptoms of Whipple diseaseSteatorrhea
Joint pain
Cardiac symptoms
Mechanism of Whipple'sInfection with T. Whipplei obstructs the lacteals in the lamina propria
Steatorrhea with Normal D-xyloseSteatorrhea due to Maldigestion
Bacterial overgrowth
Pancreatic insufficiency
Obstructed bile
Steatorrhea with Abnormal D-xyloseSteatorrhea due to Malabsorption
Short bowel
Fat enterocytes and acanthocytes (star shaped)Abetalipoproteinemia
Mechanism of Abetalipoproteinemia?AR lack of Apo-B results in Defective chylomicron
- Lipids accumulate

Small Bowel

Question Answer
Diagnosis of IBSRecurrent, crampy abdominal pain with 2+
- Pain improves with pooping
- Changes in frequency
- Diarrhea or Constipation
Related symptoms of IBSGERD, Dysphagia, Early satiety
Treatment of IBS1. Diet modification
2. Fiber
3. Antispasm: Dicyclomine, Hyoscamine
4. TCA's or SSRI
MC congenital deformity of the GI tract?Meckel diverticulum
Cause of Meckel diverticulumPersistent Omphalomesenteric duct aka vitelline duct
What is Meckel diverticulum?True diverticulum
Five 2's of Meckel diverticulum2 inches long
2 feet from iliocecal valve
2% of population
Presents in first 2 years
2 types of epithelia: Pancreatic or gastric
Melena, RLQ pain, Ilial obstructionMeckel diverticulum
MC Bowel emergency in kidsIntussusception
What is intussusception?Telescoped proximal bowel into a distal segment
Where does intussusception usually happen?Ileocecal junction
Symptoms of INtussusception?Bloody Currant Jelly Stool
What is seen on imaging studies with Intussusception?Bull's eye appearance of small bowel on ultrasound
Cause of Intussusception?Idiopathic
Adenovirus infection
IleusIntestinal hypomotility without obstruction
Ischemic colitisIschemia of the intestine
Where does ischemic colitis usually happen?Watershed areas: Splenic flexure (IMA-SMA) or Distal colon
Crazy pain with eating in an old personIschemic colitis
Meconium ileusBaby doesn't pass first stool
Causes of meconium ileusObstruction, usually due to Cystic Fibrosis or Hirschsprung
What population is susceptible to necrotizing enterocolitisPremature, formula fed babies
Complication of necrotizing enterocolitis?Pneumatosis intestinalis: Gas in small intestine
What are the most common causes of small bowel obstruction?[ABC's]
Adhesions (MC)
Bulge (hernia) (2MC)
Cancer, usually metastatic colorectal


Question Answer
Improved with defecationIBS
Alternating Diarrhea/constipationIBS
Ectopic acid-secreting Gastric/Pancreatic epitheliumMeckel Diverticulum
Currant jelly stoolIntussusception
Bull's eye UltrasoundIntussusception
Post-opIntestinal ileus
CF and hirschsprungMeconium ileus
NICU fed to earlyEnterocolitis
Pneumatosis intestinalisNecrotizing enterocolitis
Out of proportion GI painIschemic colitis


Question Answer
Carcinoid tumorNeuroendocrine tumor found in appendix, ileum, rectum and lung secreting Serotonin Histamine, and PG's
Carcinoid syndromeBronchospasm
Right-sided heart murmur (deposit in heart valve)
Treatment of Carcinoid symptoms (serotonin syndrome)Octreotide (Somatostatin analogue)
What is the appearance of carcinoid tumor?Oval-round nuclei with identically shaped/sized tumor cells
What cells are Intestinal carcinoid tumors derived from?Enterochromaffin (endocrine) cells
Where are Carcinoid tumors in the intestine most commonly found?Ileum.
Also appendix and rectum


Question Answer
Hirschsprung diseaseDefective relaxation and peristalsis due to lack of GI innervation (ganglion cells/enteric plexus)
What is the primary cause of Hirschsprung disease?Failure of the Neural crest migration
Results in a lack of Auerbach/Meissner plexus
Symptoms of HirschsprungBilious emesis
Fail to pass meconium in first 24 hours
What chromosomal abnormality is associated with Hirschsprung?Down syndrome
VolvulusTwisting of the bowel around the mesentary, which can lead to obstruction and infarction
What parts of the GI tract are susceptible to volvulus?Cecum or Sigmoid
Who gets volvulus?Old people
What bacterial flora are normally found in the colon?Bacteroides Fragilis (MC)
E. coli
Proteus mirabilus, vulgaris, Klebsiella
EnterobacteraciaG-, Facultative Anaerobic, Ferment sugar to Lactic acid
Common cause of Appendicitis in adultsFecalith: obstructing fecal stone
Common cause of Appendicitis in children?Viral infection: Hyperplasia of lymphoid tissue (MALT tissue)
Presentaiton of AppendicitisN/V, periumbilical pain → later localizes to McBurney's points (RLQ rebound tenderness)
Where is McBUrney's point?2/3 from umbilicus to Ant-sup Iliac spine
Treatment of AppendicitisConfirm with CT or US
Appendicitis differentialEctopic pregnancy


Question Answer
MC polypHyperplastic polyp (rectum, rectosigmoid)
Hyperplastic polypColonic Gland hyperplasia
Adenomatous polypsPrecancerous!!
MC pre-cancerous polypVillous adenoma [VILLAIN]
GlandularTubular adenoma
VilliVillous adenoma
Polyps in a kid?Juvenile polyp
Polyp associated with APC and KRAS?Adenomatous
CpG hypermethalation polypSessile (Serrated) Polyp
BRAF mutationSessile (serrated) Polyp


Question Answer
What gene mutation is associated with FAP?AD mutation on Chromosome 5q leading to mutation of APC tumor suppressor
What is the pathogenesis of FAP?Adenoma-Carcinoma sequence:
Loss of APC → KRAS mutation →p53 mutation →DCC = Carcinoma
Thousands of rectal polyps arising after pubertyFAP (familial adenomatous polyposis)
FAP + bone/soft tissue tumors + supernumary teethGardner syndrome
FAP + CNS tumorTurcot syndrome
What tumor is associated with Turcot?Medulloblastoma
GI Hamartomas + Hyperpigmented lips, hands, genitalsPeutz-Jeghers
Is there risk associated with Peutz Jeghers?Yes! 50% will develop cancer: GI cancer
What gene mutation is associated with HNPCC?Autosomal dominant mutation of DNA musmatch repair genes
What is the pathogenesis of HNPCC?Microsatellite instability: DNA mismatch repair mutations accumulate and cause repeating segments of DNA
3-2-1 diagnosisLynch (HNPCC):
3 relatives with Lynch
2 generations
1 diagnosed before 50 y.o.
Which part of the colon is always involved in HNPCC?Proximal


Question Answer
How common is colorectal cancer?3MC incidence and death
Risk factors for colorectal cancer>50 y.o.
IBD, especially UC
Meat and low fiber
Which bacteria is associated with colorectal cancer?Strep bovis
How does right-sided colorectal cancer present?Iron deficiency anemia!
How does left sided colorectal cancer present?Thin poo, Hematochezia
Barium enema sign of colorectal cancerApple core lesion
Screening of colorectal cancerColonoscopy x10 years
Stool occult blood x1year
Barium enema
Colorectal tumor marker?CEA. Not specific but good for monitoring.


Question Answer
Pseudodiverticulum?outpouching of only the mucosa and submucosa
Where do false divertiula usually occur?Where vasa recta perforate muscularis externa
Intraluminal pressure causes focal weakness in the wall
DiverticulosisLots of false diverticula in the colon, especially sigmoid
Seen in majority of people over 60.y.o.
Symptoms of DiverticulosisAsymptomatic
Vague discomfort
DiverticulitisInflammation of diverticula! LLQ, fever leukocytosis
Pneumaturia(Air or poo) in the pee
Seen with Diverticulitis


Question Answer
Embryologic origin above Pectinate lineEndoderm
Internal hemorrhoidsAbove pectinate lines. No pain!
Blood supply above Pectinate lineSuperior rectal artery
Venous drainage above Pectinate lineSuperior rectal vein
Cancer above Pectinate lineAdenocarcinoma
Embryologic origin below Pectinate lineEctoderm
External hemorrhoidsBelow Pectinate line
Very painful! Innervated by cutaneous nerves
Cancer below Pectinate lineSquamous cell cancer (HPV 16, 18 31)
Arterial supply below Pectinate lineInferior rectal artery (pudendal)
Venous drainage below Pectinate lineInferior Rectal vein (Internal pudendal →IVC)
ProctitisInflammation of Perianal region and rectum
Cause of proctitisPoo hanging around too long
Associated with proctitis?Ulcerative colitis
Treatment of proctitis?Topical steroid