GI Flashcards
Newborn with instestines herniating through ant abd wall
no peritoneum over intestines
gastroschisis
What causes duodenal atresia?
failure to recanalize
assc with trisomy 21
Newborn
palpable olive mass in epigastric region
projectile vomit
Pyloric stenosis
hypertrophy of pylorus
nonbilious vomit
Development of pancreas
ventral bud-head/main duct
dorsal-tail/body/accessory duct
annular pancreas if ventral goes around duodenum
pancreas divisum if fail to fuse
Falciform ligament
from fetal umbilical vein
from ventral mesentery
ligamentum teres hepatis
Hepatoduodenal ligament
portal triad within (hepatic a./portal vein/common bile duct)
Pringle maneuver to control bleeding
Nerve plexi of GI tract
Meissner’s-submucosa
Auerbach’s-muscularis externa
Wave frequencies of GI tract
stomach-3/min
duodenum-12/min
ileum-8/min
Location of Peyer’s patch
ileum
N/V
postprandial stabbing epigastric pain
malnutrition
SMA syndrome
SMA entraps 3rd portion of duodenum
intestinal obstruction
Collateral circulations of GI tract (4)
Sup epigastric (internal thoracic) w/ inf epigastric (external iliac) Sup pancreaticoduodenal (celiac) w/ inf (SMA) middle colic (SMA) w/ L colic (IMA) Sup rectal (IMA w/ inf rectal (internal iliac)
Appendix development
re-entry after herniation in URQ
drops into LRQ
can remain in URQ and cause pain
Portal system anastomoses (3)
L gastric w/ esophageal
paraumbilical w/ sup/inf epigastric
sup rectal w/ mid/inf rectal
Drainage above and below pectinate/dentate line
above-deep nodes (para-aortic)
below-sup inguinal nodes
Liver zones
1-periportal/impacted by viral hepatitis
2-intermediate
3-pericentral v./impacted by ischemia & toxic injury (has CYP450) and alcoholic hepatitis
Jaundice
dark urine
light stools
Biliary stenosis
Bilious vomiting
double bubble on radiograph
Duodenal atresia
failure to recanalize
Femoral region structures
Lat to medial
Nerve/Artery/Vein/Lymph (NAVeL)
nerve is not in femoral sheath, others are
Bug with dental plaques
Strep mutans
makes acid to demineralize bone
Carb absorption in GI
Glc/Gal via SGLT
Frc via Glut-5
then Glut-2 from cell into blood for all
Role of ApoE
liver recognition/uptake of chylomicrons
Role of ApoCII
activates LPL
allows uptake of TG’s in cells
Respiratory distress
trouble eating in newborn
hourglass stomach
diaphragmatic hernia
Young male with bulge near femoral triangle
lateral to inf epigastric artery
Indirect hernia
young boys
failure of processus vaginalis closure
covered by spermatic fascia
Bulge in lower abd wall
55 y/o man
medial to inf epigastric artery
Direct hernia
Hesselbach’s triangle
through external inguinal ring only
Increases gastric motility/H+ secretion/gastric mucosa growth
Gastrin (G cells of antrum)
stimulated by distention/vagal
especially Phe and Trp aa’s
Increases pancreatic secretions/gallbladder contraction
Decreased gastric emptying
Cholecystokinin (CCK) (I cells of duodenum/jejunum)
increased by FA’s and AA’s
acts on neural muscarinics
Increases bicarb/bile secretion
Decreases gastric acid secretion
Secretin (S cells of duodenum)
increased by acid/FA’s in duodenum
Decreases gastric acid/pepsinogen/pancreatic secretion/insulin & glucagon release
Somatostatin (D cells of pancreas/GI mucosa)
increased by acid
inhibitory/antigrowth hormone effects
Increases insulin release
Decreases H+ secretion
GIP (K cells duodenum/jejunum)
increased by FA’s/AA’s/Glc
Increases water/electrolyte secretion
relaxes smooth m. of GI
VIP (parasympathetic ganglia in sphincters)
increased by distention/vagus
Impact of VIPoma
watery diarrhea
hypokalemia
achloryhdria
Produces migrating motor complexes
Motilin
increased in fasting state
Pepsinogen characteristics
secreted by Chief cells
activated by H+
Causes of increased gastric H+ secretion (3)
histamine
ACh
gastrin
Causes of decreased gastric H+ secretion (4)
somatostatin
GIP
prostaglandin
secretin
Pathway for gastrin stimulation of H+ secretion
G cells secrete gastrin
gastrin causes histamine release from ECL cells
histamine stimulates parietal cell H+ secretion
Impact of NSAIDs on stomach
Decreased COX1 causes less PGE2
less bicarb secretion, more H+/ulcers
Trypsinogen activation
converted to trypsin by enteropeptidase (in duodenum)
trypsin then breaks down more trypsinogen and other peptides
autodigestion prevention: bicarb/trypsin inhibitors in pancreas
B12 absorption
needs intrinsic factor (from stomach)
absorbed in ileum (along with bile acids)
Rate limiting step of bile acid synthesis
cholesterol 7alpha-hydroxylase enzyme
Cause of achalasia
loss of Auerbach's (myenteric) plexus can be secondary to Chagas/Crest syndrome lower esophageal sphincter cannot relax bird's beak on barium swallow assc with esophageal SSC
Assc with esophagitis
CMV (linear ulcers)
Candida (white pseudomembrane)
HSV-1 (punched out ulcers)
Mucosal lacerations at LES
severe vomiting/alcoholic
Mallory-Weiss tears
leads to hematemesis
Transmural esophageal rupture
violent retching
Boer-Haave syndrome
Dysphagia
anemia
glossitis
Plummer Vinson syndrome
women with anemia
esophageal webs
Chronic GERD
nonciliated columnar epithelium at lower esophagus
Barrett’s esophagus
metaplasia-squamous to columnar
increased risk of adenocarcinoma
Esophageal cancer prevelance
SSC worldwide most common
adenocarcinoma most common in U.S.
Failure to thrive in infancy
nystagmus/ataxia
pellegra (dermatitis/diarrhea/dementia) sx
Hartnup’s disease
lack of neutral AA transporters in kidney/GI
no 5HT/melatonin/niacin made
Acid fast
foamy macrophages in intestines
60 y/o male
arthralgia/abd pain
Whipple’s disease
dx with PAS stain (+)
Tropheryma whipplei (gram +)
Osmotic diarrhea
milk intolerance
Disaccharidase deficiency (lactase)
Fat accumulation in enterocytes
malabsorption in childhood
neuro sx
Abetalipoproteinemia
decreased ApoB decreases chylomicrons/VLDL in blood
due to MTP protein
Steatorrhea
assc with HLA-DQ2 and DQ8
blunting of villi
assc with dermatitis herpetiformis
Celiac sprue
gliadin intolerance (autoimmune)
transglutaminase Abs for screening
Causes of acute gastritis
NSAIDs
burns (Curling’s ulcer/decreased mucosa)
brain injury (Cushing’s/increased ACh & H+)
Fundus/body chronic gastritis
Autoimmune against partietal cells
achlorhydria/pernicious anemia
gastric carcinoma
Antrum chronic gastritis
H. pylori infection
increased MALT lymphoma
Gastric hypertrophy
increased mucous cells/excess mucus
protein loss
Menetrier’s disease
increased gastric carcinoma
parietal cell atrophy as well (achlorhydria)
Signet ring cells
thick stomach wall
linitis plastica
Diffuse stomach cancer
from metastasis of lung/breast
Virchow’s node
L supraclavicular node from stomach metastasis
Krukenberg’s tumor
bilateral mets to ovaries
has signet ring cells
Subq perumbilical metastasis
Sister Mary Joseph’s nodule
Increased gastrin secretion
increased H+ in jejunum/damage to intestines
assc with MEN type 1
Zollinger-Ellison syndrome
pancreas tumor secreting gastrin
Oxate stones in kidney skip lesions string sign on barium swallow failure to thrive in children erythema nodosum
Crohn's disease Cobblestone mucosa linear ulcers (bear claw ulcers) noncaseating granulomas assc with ankylosing spondylitis/migratory polyarthritis
Urate stones in kidney
rectal involvement
Pseudopolyps
lead pipe colon
Ulcerative colitis autoimmune no granulomas risk of perforations assc with sclerosing cholangitis/colorectal cancer pyoderma gangrenosum
Colonic pseudo-obstruction
gaseous distention
Ogilvie syndrome
Hematochezia
low fiber diet
Diverticulosis
focal weakness in colonic wall
false diverticula
Porch on x-ray at post pharynx
dysphagia
halitosis
man 65 y/o
Zenker’s diverticulum (false diverticulum)
Killian’s triangle b/t thryopharyngeal/cricopharyngeal portions of inf pharnygeal constrictor
RLQ pain
ectopic gastric mucosa at ileum
painless GI bleeding
Meckel's diverticulum 2 inches 2 ft from ileocecal valve 2% of population persistence of the vitelline duct
1 y/o
currant jelly stool
sausage shaped mass
intussusception
telescoping of bowel
compromise of blood supply
assc with adenovirus
Unproductive retching
78 y/o male
abd pain
volvulus
causes blockage/infarct
from laxity of ligaments
Chronic constipation
dilated proximal colon
infant
Hirschsprung’s disease
neural crest cells did not migrate
Auerbach/Meissner’s plexi not present
Assc with duodenal atresia
Down’s syndrome
Cause of meconium ileus
cystic fibrosis
Precancerous polyp characteristic in GI
adenomatous
lg size
villous histology
dysplasia
Multiple polyps in 14 y/o female
majority in rectum
Juvenile polyposis syndrome
increased risk of adenocarcinoma
AD
multiple hamartomas throughout GI
increased colorectal cancer risk
Peutz-Jeghers syndrome
also hyperpigmented mouth/lips/hands/genitalia
6 y/o
ulcerations on uvula/soft palate
Herpangina
from Coxsackie A
Familial adenomatous polyposis
AD
mutation of APC on chromosome 5
pancolonic
Osseous & soft tissue tumors
multiple polyps throughout colon
retinal pigment hypertrophy
Gardner’s syndrome
malignant CNS tumor
multiple polyps throughout colon
Turcot’s syndrome
Hereditary nonpolyposis colorectal cancer
HNPCC/Lynch syndrome
DNA mismatch repair gene mutation
proximal colon
AD
Apple core lesion on barium enema
61 y/o male
anemia
Colorectal cancer
Colorectal cancer pathogenesis
DNA mismatch repair gene mutation leads to HNPCC syndrome from accumulation of mutations (15%)
APC/beta-catenin pathway (85%)
loss of APC gene, K-RAS mutation, then loss of p53
R sided heart murmurs wheezing diarrhea flushing increased 5HT
Carcinoid syndrome (neuroendocrine tumor) sx only occur if carcinoid tumor (or mets) is outside GI tract
ALT>AST
viral hepatitis
AST>ALT
alcoholic hepatitis
see Mallory bodies
see Hobnail appearance in cirrhosis
Increased alkaline phosphatase (ALP)
obstructive liver disease
bone disease
or bile duct disease
Increased gamma-glutamyl transpeptidase (GGT)
liver/biliary disease
Disease with increased amylase
Mumps
also pancreatitis
Decreased ceruloplasmin
Wilson’s disease
Child Hypoglycemia vomiting hepatomegaly viral infection
Reye’s syndrome
tx of aspirin precipitates
fatty liver/mitochondrial abnormalities
hepatoencephalopathy
Causes of hepatocellular carcinoma (6)
Hepatitis B/C Wilson's disease hemochromatosis alpha1-antitrypsin deficiency aflatoxin from Aspergillus
Hepatic tumor
Use of steroids/oral contraceptives
Hepatic adenoma
benign
Angiosarcoma of the liver assc
arenis
polyvinyl chloride
Centrilobar necrosis
Nutmeg liver
R sided heart failure
or Budd Chiari syndrome
venous backup into liver
Ascites abd pain hepatomegaly no JVD multiple thrombi
Budd-Chiari syndrome
IVC or hepatic vein occlusions
thrombotic events
PAS (+) globules in liver
cirrhosis
panacinar emphysema
Alpha1-antitrypsin deficiency
misfolded gene product
intrahepatic accumulations of A1AT
Neonatal jaundice with no pathology
immature UDP-glucuronyl transferase
unconjugated hyperbilirubinemia
kernicterus
Elevated unconjugated bilirubin
no hemolysis
increased bilirubin with fasting
Gilbert’s syndrome
decrease in UDP-glucuronyl transferase
or decreased bilirubin uptake
Jaundice
kernicterus (brain damage)
increased unconjugated bilirubin
death within a few years
Crigler-Najjar syndrome
absent UDP-glucuronyl transferase
tx with plasmpheresis (type 1)
tx with phenobarbital (type 2)
increased conjugated bilirubin
black glossy liver
Dubin-Johnson syndrome
defective liver excretion
Increased conjugated bilirubin
no black liver
Rotor’s syndrome
more mild than Dubin Johson
Cirrhosis corneal deposits hepatocellular carcinoma hemolytic anemia asterixis
WIlson's disease decreased copper excretion Basal ganglia degeneration (Parinsonianism) defect in ATP7B gene chromosome 13 tx with penacillamine corneal deposits=Kayser-Fleischer rings
cirrhosis
DM
bronze skin
CHF
hemochromatosis bronze diabetes AR or from chronic transfusions C282Y or H63D mutation of HFE gene assc with HLA-A3 tx with deferoxamine/deferasirox
Onion skinning fibrosis of bile duct
beading appearance
increased IgM
Primary sclerosing cholangitis
assc with ulcerative colitis
Lymphocytic inflitrate of bile duct
granulomas
increased AMA Abs
Primary biliary cirrhosis
autoimmune rxn
assc with CREST/RA/celiacs
tx with ursodeoxycholic acid
Extrahepatic obstruction pruritis jaundice (conjugated) dark urine hepatosplenomegaly
Secondary biliary cirrhosis
increase P on intrahepatic ducts cause injury
Pork/mimics appenditis bug
yersinia eterocolitis
Rice/meats bug diarrhea
Bacillus cereus
Raw chicken/eggs bug diarrhea
Salmonella
Poultry bloody bug diarrhea
Campylobacter jejuni
Cruise ship bug diarrhea
Norwalk virus
Infants/young children bug diarrhea
Rotavirus
beavers/mtns bug diarrhea
Giardia lamblia
AIDS/immunocompromised bug diarrhea
cryptosporidiosis
Antibiotic tx bug diarrhea
C. diff
Female 45 y/o obese RUQ pain jaundice fever
Gallstones black stone-hemolysis brown stone-infection radiolucent-cholesterol can cause fistula b/t intestine/gallbladder
Epigastric abd pain radiating to back
N/V and anorexia
hypocalcemia
diffuse fat necrosis
Acute pancreatitis
elevated amylase and lipase
can cause DIC/ARDS
low Ca2+ due to precipitating out
Jaundice
abd pain radiating to back
wt loss
migratory thrombophlebitis (Trouseeau’s syndrome)
Pancreatic adenocarcinoma
jaundice from pancreatic head obstructing bile duct
assc with CA-19-9 and CEA (less specific)
H2 blocker MOA
H2 receptor blocking on parietal cells
decreases H+ secretion
MOA of Proton pump inhibitors
irreversibly bind H+/K+ ATPase of parietal cells
increased risk of pneumonia/C diff and low Mg2+
MOA of bismuth/sucralfate
bind to ulcer base/physical protection
allows bicarb secretion to reestablish pH
MOA of misoprostol
PGE1 analog
inhibits cAMP
increases bicarb and mucous secretion
decreases acid secretion
Other uses of misoprostol (not GI)
maintain PDA induce labor (contracts smooth muscle)
Use and MOA of octreotide
somatostatin analog
used for variceal bleeds/acromegaly/VIPoma/carcinoid tumors
Antacid adverse effects
all cause hypokalemia
Al(OH)3-constipation/m. weakness/low phosphate
Mg(OH)2-diarrhea/cardiac arrest/hyporeflexia
Ca(CO3)2-hypercalcemia/rebound acid increase
Lactulose uses
osmotic laxative (for constipation)
draws water out by osmotic load
can also be used for hepatic encephalopathy
MOA of infliximab
TNF-alpha monoclonal Ab
for Crohn’s/UC/RA
MOA of ondansetron
5HT-3 antagonist (centrally acting)
antiemetic
MOA of metoclopramide
D2 receptor antagonist
increases resting tone/contractility/motility
used for gastroparesis
can cause parkinsonianism
