GI Flashcards
What genetic defect is duodenal atresia associated with?
Down Syndrome
What exposure is associated to hypertrophic pyloric stenosis?
Macrolides
What is derived from ventral pancreatic bud?
Uncinate process
Main pancreatic duct
What is derived from dorsal pancreatic bud?
Body
Tail
Isthmus
Accessory pancreatic duct
What is it called when the vetnral and dorsal buds of the pancreas fail to fuse?
Pancreas divisum
Falciform Ligagment
- Liver –> anterior abdominal wall
- Ligamentum teres hepatis (derivative of fetal umbilical vein)
Hepatoduodenal Ligament
- Liver –> duodenum
- Portal triad: proper hepatic a, portal v, common bile duct
Pringle Maneuver
Compress hepatoduodenal ligament during surgery to control bleeding
Gastrohepatic Ligament
- Liver –> lesser curvature of the stomach
- Gastric a
- May be cut during surgery to access lesser sac
Gastrocolic Ligament
- Greater curvature and transverse colon
- Gastroepiploic arteries
- Part of GO
Gastrosplenic Ligament
Greater curvature and spleen
- Short gastrics, L gastroepiploic
- Part of GO
Splenorenal Ligament
Spleen –> posterior abdominal wall
- Splenic artery and vein, tail of pancreas
Where are Brunner glands found and what do they secrete?
HCO3-
Where are Peyer Patches found?
Ileum
Where does celiac trunk come off aorta?
T12/L1
Where does SMA come off aorta?
L1
Where does IMA come off aorta?
L3
Where does aorta bifurcate into left and right common iliac?
L4
SMA Syndrome?
- Intermittent intestinal obstruciton sx (postprandial pain) when 3rd portion of duodenum (transverse) is compressed between SMA and aorta
- Diminished fat (low body weight, malnutrition)
Above pectinate line - A, V, L, N
A: IMA (superior rectal artery) V: IMV (superior rectal vein) L: internal iliac lymph nodes N: visceral - Internal hemorrhoids not painful
Below pectinate line - A, V, L, N
A: inferior rectal artery (from internal pudendal)
V: inferior rectal v –> internal pudendal v –> internal iliac –> common iliac –> IVC
L: superficial inguinal nodes
N: inferior rectal branch of pudendal (somatic)
- External hemorrhoids (painful if thrombosed), anal fissures, SCC
Femoral Sheath Contents
- Femoral vein, artery, and canal (deep inguinal LN) but NOT femoral nerve
- Lateral to medial: nerve, artery, vein, lymphatics
What structures do indirect inguinal hernias go through?
- Male infants
Internal (deep) inguinal ring, external (superficial) inguinal ring, into scorum
- Covered by all three layers of spermatic fascia
Indirect inguinal hernia relationship to inferior epigastric vessels?
- LATERAL to inferior epigastric vessels
What is the cause of indirect inguinal hernia?
Failure of processus vaginalis to close (can form hydrocele)
What structures do direct inguinal hernias go through?
- Old men
Inguinal (Hesselbach) triangle directly through abdominal wall
- Goes through external (superficial) inguinal ring only
- Covered by external spermatic fascia
Direct inguinal hernia relationship to inferior epigastric vessels?
MEDIAL to inferior epigastric vessels
What structures do femoral hernias go through?
- Females
- Femoral canal –> protrudes below inguinal ligament
Femoral hernia relationship to pubic tubercle?
BELOW and LATERl to pubic tubercle
Borders of inguinal (Hesselbach) triangle?
Inferior epigastric vessels, lateral border of rectus abdominis, inguinal ligament
What can cause increased levels of gastrin?
Chronic PPI use, chronic atrophic gastritis (H. pylori), ZE Syndrome (gastrinoma)
What is octreotide used for?
Acromegaly, carcinoid syndrome, variceal bleeding
- Somatostatin analog
How does erythromycin stimulate intestinal peristalsis?
Motilin R agonists –> produces migrating motor complexes
Loss of NO secretion implicated in what disorder?
Achalasia –> increases LES tone
AI destruction of parietal cells –>
Chronic gastritis
Pernicious anemia
Which cells secrete pepsin?
Chief cells
What E converts trypsinogen to trypsin?
Enterokinase/enteropeptidase (brush border E on duodenal and jejunal mucosa)
Function of D-xylose absorption test?
- Distinguishes GI mucosal damage from other causes of malabsorption
Where is iron absorbed?
- Duodenum as Fe2+
Where is folate absorbed?
Small bowel
Where is B12 absorbed?
Terminal ileum along with bile salts
Requires IF
E responsible for conjugating bilirubin?
UDP-glucuronosyl-transferase
What infection can cause achalasia?
Chagas (T. cruzi)
Boerhaave Syndrome
- Transmural distal esophageal rupture with pneumomediastinum
- Due to violent retching
Candida esophagitis
White pseudomembrane
HSV-1 esophagitis
Punched-out ulcers
CMV esophagitis
Linear ulcers
Plummer-Vinson Syndrome
- Dysphagia + Fe deficient anemia + esophageal webs
- Increased risk of SCC
What does Barrett esophagus increase the risk of?
Adenocarcinoma
Menetrier Disease
- Gastric hyperplasia of mucosa –> hypertrophied rugae (looks like brain gyri)
- Excess mucus production w/ protein loss and PC atrophy with decreased acid production
- Precancerous
What are skin manifestations of gastric cancer?
Acanthosis nigricans (axillary region) Leser-Trelat sign (seborrheic keratosis)
Causes of intestinal type gastric cancer?
H pylori Dietary nitrosamines (smoked foods) - Japan Tobacco smoking Achlorhydria Chronic gastritis
Characteristics of diffuse gastric cancer?
- Signet ring cells (mucin-filled cells with peripheral nuclei)
- Grossly thickened and leathery (linitis plastica)
Ulcer hemorrhage in duodenum?
Posterior
Rupture gastric ulcer on lesser curvature of stomach is bleeding from..?
Left gastric a
Ruptured gastric ulcer on posterior wall of duodenum is bleeding from…?
Gastroduodenal artery
Ulcer perforation in duodenum?
Anterior
What is Sudan stain for?
Fecal fat
HLA associated with celiac?
HLA-DQ2 and DQ8
Celiac antibodies?
IgA anti-tissue transglutaminase
Anti-endomysial
Anti-deamidated gliadin peptide
Whipple DZ
- Cardiac sx, arthralgias, neuro sx
- Older men
- Tropheryma whipplei (IC G-)
- PAS+
- Foamy macs in intestinal LP
Increased risk of Hirschprung with what genetic defect?
Down syndrome
Rectal suction bx for Hirschprung in what layer?
Submucosa –> lack of ganglion cells
Currant jelly stools?
intussusception
Intussusception in adults?
Mass/tumor
Intussusception in adults?
Idiopathic, infection (Peyer patch hypertrophy)
Intussusception associated iwth what pathologic lead point?
Meckel diverticulum
Most common cause of small bowerl obstruction?
Adhesions ater surgery
Meconium Ileus
CF - prevents stool passage at birth
Necrotizing Enterocolitis
- Premature, formula fed infants
- Feeding intolerance, distended abdomen, bloody stools
Necrosis of intestinal mucosa w/ possible perforation –> pneumatosis intestinalis, free air in abdomen, portal venous gas
Gardner Syndrome
FAP
Osseous and soft tissue tumors
Congenital hypertrophy of retinal pigment epithelium
Impacted/supernumerary teeth
Turcot Syndrome
FAP + malignant CNS tumor
Hyperpigmented mouth/lips/hands/genitalia?
Peutz-Jeghers Syndrome (AD)
- Increased risk of breast and GI cancers
- Hamartomas
Genetic transmission of all polyposis syndromes
AD
Bacterial infection associated with CRC?
Streptococcus bovis (also causes endocarditis)
Tumor marker for CRC?
CEA
Pathogenesis of Reye Syndrome
Histo: mt abnormalities, fatty liver (microvesicular fatty change)
Patho: aspirin metabolites decrease beta-oxidation by reversible inhibition of mt E
When should you give children aspirin?
Kawasaki DZ
Histo of hepatic steatosis
Macrovesicular fatty change
- Reversible with alcohol cessation
Histo of alcoholic hepatitis
Swollen & necrotic hepatocytes w/ neutrophils MALLORY BODIES (intracytoplasmic eosinophilic inclusions of damaged keratin)
Which zone is alcohol cirrhosis seen in?
Zone III (around central vein)
MOA of lactulose in hepatic encephalopathy?
Increased NH4+ generation
MOA of rifamixin or neomycin in hepatic encephalopathy?
Decreased NH4+ producing gut bacteria
Fungi associated with HCC?
Aflatoxin from Aspergillus (stored grains)
- Induces p53 mutations
Tumor marker for HCC?
Alpha-fetoprotein
Most common benign liver tumor?
Cavernous hemangioma
Liver tumor associated with OCP and anabolic steroid use?
Hepatic adenoma
Liver tumor associated with arsenic, vinyl chloride?
Angiosarcoma
Nutmeg liver?
Budd chiari syndrome
Pathogenesis of alpha-1-antitrypsin deficiency in liver vs. lugn
Liver: increased alpha1AT –> misfolded gene product protein aggregates in hepatocellular ER
Lung: decreased alpha1AT –> uninhibited elastase –> panacinar emphysema
Alpha-1-antitrypsin deficiency genetics
Co-dominant trait
Where does bilirubin deposit in neonates?
Basal ganglia
Gilbert Syndrome and Crigler Najjar E
UDP-glucuronosyltransferase (increase in unconjugated bilirubin)
Type II Crigler Najjar Rx
Phenobarbital (increases liver E synthesis)
Dubin-Johnson Syndrome
- Conjugated hyperbilirubinemia
- Defective liver excretion –> grossly black liver
Rotor Syndrome
Without black liver
- impaired hepatic uptake and excretion
Wilson DZ Gene
ATP7B gene on chromosome 13 –> heptocyte copper-transporting ATPase –> lack of Cu transport into bile –> lack of Cu incorporation into ceruloplasm
AR
Rx of Wilson DZ
Chelation with penicillamine or trientine
Oral zinc
Unique thing with Wilson DZ
Kayser-Fleishcer ring (deposits in Descemet membrane in cornea)
Wilson DZ lab
Decreased serum cerruloplasmin, increased urine copper
Hemolytic anemia
Renal DZ
Liver DZ
Hemochromatosis gene
HFE gene (C282Y > H63D) on Chr 6 --> abnormal Fe sensing and increased intestinal absorption --> damage due to generation of free radicals AR
Hemochromatosis labs
Increased ferritin and iron
Decreased TIBC
Increased transferring saturation
Special stain for hemochromatosis
Prussian blue stain
Arthropathy in hemochromatosis caused by?
Calcium pyrophosphate
Hemochromatosis rx
Repeated phlebotomy
Chelation with deferasirox, deferoamine, oral deferiprone
Primary Sclerosing Cholangitis Path
- men with IBD
- Onion skin bile duct fibrosis
- Beading of intra and extrahepatic bile ducts
PSC associated with:
- UC
- pANCA +
- increased IgM
- Increased risk of cholangiocarcinoma and gallbladder cancer
Primary biliary cirrhosis path
- middle aged women
AI –> lymphocytic infiltrate and granulomas –> destruction of intralobular bile ducts
PBC associated with:
- Anti-mt Ab +
- Increased IgM
Infection associated with cholecystitis
CMV
Cause of porcelain gallbladder
Chronic cholecystitis
Porcelain GB associated with increased risk of…?
Adenocarcinoma of gallbladder
Tumor marker for pancreatic adenocarcinoma?
CA19-9
