Gastrointestinal - Uworld Flashcards
8574: What are the branches of the splenic artery?
pancreatic
short gastric
left gastroepiploic
8574: What main artery does the splenic artery branch off?
Celiac artery
8574: What branch of the splenic artery is vulnerable to ischaemia following splenic artery blockage?
short gastric - (supplies superior fundus - greater curvature of stomach) - it has poor anastomoses
8574: What does the left gastroepiploic artery anastamose with?
Right gastroepipoloic artery - (supplies inferior border of greater curvature of stomach)
1068: What monosaccharide has the fastest rate of metabolism in the glycolytic pathway? Glucose, Fructose, Galactose?
Fructose - it by-passes Phosphofructokinase-1 (PFK-1), a regulatory step of glycolysis
15383: What is the cause of ‘pill oesophagitis?
Prolonged contact of ‘high risk’ medication with mucosal lining of proximal oesophagus -
often in restriction areas: aortic arch, carina, gastroesophageal junction, enlargement left atrium
Tx: remain upright after swallowing, drink water
15383: What drugs cause pill oesophagitis?
Tetracyclines - doxycycline
Bisphosphonates - alendronate
potassium chloride
NSAIDS
s/s: odynophagia, retrosternal chest pain
80: In hepatobillary scanning for acute cholecystitis, is the gallbladder visualised / not visualised?
Not visualised.
Obstruction prevents radiotracer uptake in the gall bladder.
(Tracer preferentially uptaken by hepatocytes) - seen in liver with excretion into common bile duct and proximal small bowel.
Uptake in GB shows tracer concentration (imageC)
80: What is the main cause of acute cholecystitis?
gallstone blocking cystic duct
will see: GB inflammation - wall thickening, pericholecystic fluid
11817: What is a sentinel lymph node?
The first 1-4 nodes that drain a specific colon segment -
first site for colon cancer metastasis
11817: What sites do the superior, middle and inferior rectal lymph nodes drain into?
superior - Inferior mesenteric LN
middle - internal iliac LN
inferior - superior inguinal LN
11817: What structures does the celiac LN drain?
hepatic, splenic, gastric LN
11817: What structures does the superficial inguinal LN drain?
genitalia (parts), buttocks, anus (below dentate line), abdominal wall (below umbilicus)
superficial inguinal LN - situated below inguinal ligament
11817: What structures does the superior mesenteric LN drain?
ileum, jejunum, vermiform process, ascending and transverse colon
328: What are 2 examples of false diverticula?
Colonic
Zenkers (upper oesophagus)
(not all 3 layers involved)
21083: In BIND (bilirubin induced neurologic deposition) - where is bilirubin deposited?
basal ganglia
brainstem nuclei
21083: What are signs/symptoms of acute and chronic BIND?
Acute: subtle, poor feeding, inconsolable, opisthotonus (tone changes), apnoea
Chronic (Kernicterus): upward gaze palsy, dystonia, chorea, sensorineural hearing loss, developmental delay,
1838: What is the main deficiency seen from a prolonged vegan diet?
B12 deficiency
water soluble vitamin
obtained purely from diet - meat, dairy, fish
can’t be obtained from plants alone
Total gastrectomy (los of intrinsic factor) - also a cause of B12 deficiency
1838: What is combined degeneration of spinal cord?
seen in B12 deficiency
affects lateral and posterior columns, mostly due to demyelination
101: Dublin Johnson syndrome (AR) is caused by defective hepatic excretion of:
bilirubin glucuronides
(‘glucuronic acid’ conjugates bilirubin)
will also see:
Impaired epinephrine excretion, seen as (pink inclusions) in lysosomes - causing (black liver)
283: What are 3 main causes of HIV -associated oesophagitis?
& their typical ulcer presentation?
Candida - white pseudomembranes
CMV - linear
HSV - punched out
403: primary biliary cholangitis is a ________________ disorder that commonly affects ________________?
autoimmune
middle aged women
403: the main symptoms & lab findings of primary biliary cholangitis are?
symptoms:
fatigue
pruritus
jaundice
cholestasis
labs:
raised ALP
raised gamma glutamyl transferase
raised direct hyperbilirubinaemia
automitochondrial antibodies
403: What are the histology findings for primary biliary cholangitis?
lymphocytic infiltration + granulomatous destruction of interlobular bile ducts
1064: What vitamin deficiency causes pellagra?
niacin B3
(rough skin)
B3 deficiency characterised by 3Ds:
dementia - neuro degen, like pernicious anaemia
dermatitis - sun exposed areas
diarrhoea - atrophy columnar epithelium
1064: What amino acids can be precursors to synthesis of the coenzyme NAD+
tryptophan
niacin
14892: Eosinophilic oesophagitis is a ________ mediated disorder triggered by ____________ exposure.
T2 cell
food antigen
14892: Eosinophilic oesophagitis is most common in ________ with a history of _________ conditions. They often have solid food ___________.
males
atopic (eczema, asthma)
dysphagia
The typical presentation in eosinophilic oesophagitis is?
oesophageal rings
linear furrows
scattered small white papules - micro abscesses
eosinophilic mucosal infiltration
MALROTATION vs volvulous
midgut volvulous
19789: what are 4 common deficiencies in a vegan diet?
b12 - meat
calcium - dairy
vitamin D - dairy
iron (nonheme plant iron harder to absorb)
12068: what type of anaemia is macrocytic and linked with autoimmune disease?
Pernicious anaemia
macrocytic megaloblastic anaemia
b12 deficiency
assoc.: with autoimmune conditions - diabetes, hashimotos
(CD4 response against parietal cells)
12068: What lab findings do you find in pernicious anaemia?
serum gastrin _______
gastric pH ________
parietal cell mass _________
serum gastrin - increased (alkalinity stimulates gastrin)
gastric pH - increased (achlorhydria increases pH)
parietal cell mass - decreased oxyntic mucosa (decreased acid and IF production)
1971: pancreatic secretions are __________. A _________ increases, _________ decreases as they are exchanged at the apical surface of pancreatic ductal cells.
isotonic
HCO3
CL-
14873: pregnant women usually develop GERD at any stage during their pregnancy due to LES relaxation caused by?
oestrogen & progesterone
relax sm ms of LES - decreasing tone
Also: gravid uterus pressing on stomach can alter angle of LES
there is not an ‘increase’ in gastric acid in pregnancy
What is the cause of Gastroschisis and is it covered or uncovered?
Defect in anterior abdominal wall formation (full thickness)
Defect is periumbilical
Bowel contents end up in amniotic cavity, not covered by a membrane
Umbilicus usually normal and unaffected
What is the cause of Omphalocele and is it covered or uncovered?
Failed gut rotation and physiologic return of bowel to the abdomen
Bowel contents herniated within umbilical cord sac
Bowel is covered by a peritoneal membrane
does gastroschisis or omphalocele have higher maternal serum AFP levels?
Gastroschsis has higher AFP levels
direct AFP leakage into amniotic fluid
absorbed by maternal circulation
292: what is the most common cause of PUD - peptic ulcer disease?
Helicobacter pylori
gastric ulcer 70%
duodenal ulcer 90%
21033: out of the following normal changes in an aging liver - what decrease, what stay the same:
liver mass
cytochrome P450
ALT
hepatic regeneration
ALT - stays same
liver mass - decreased hepatic blood flow
cytochrome P450 - decreased drug metabolism
hepatic regeneration - decreased ability to recover from injury
(overall increases risk of drug-toxicity)
11548: What are 3 key symptoms and 2 pathological findings of CMV oesophagitis
symptoms:
odynophagia - pain on swallow
dysphagia - difficulty to swallow
burning/chest pain
pathology:
intracellular inclusions - owl eye (enlarged cells with basophilic or eosinophilic inclusions)
linear/shallow ulcers distal oesophagus
11548: What are 3 causes of CMV oesophagitis?
immunosuppressed patients:
- HIV
- immunosuppressant drugs
- transplant (transmitted or immunosuppressed)
321: In Meckels diverticulum -
1) what tissues can present within it?
2) if ulcer occur, are the painful/less?
3) what is the cause of Meckels diverticulum?
1) heterotopic (ectopic) - gastric, pancreatic, colonic mucosa
2) brisk and painless
3) failed obliteration of vitelline duct connecting ileum to umbilicus
11850: ____________ artery is at risk of haemorrhage/injury during cesarian if a horizontal incision is made, due to the lack of supporting _______________
inferior epigastric artery
posterior sheath
inferior epigastric arteries enter the rectus abdominus at the levels of the arcuate line
14880: what is the cause of sliding hiatal hernia?
laxity of phrenoesophageal membrane
14880: what is the cause of paraoesophageal hernia?
hole defect in phrenoesophageal membrane
What is the cause of bochdalek hernia?
failure of posterolateral diaphragm foramena to close
causes - pulmonary hypoplasia, pulmonary distress
1766: what effect is lansoprazole (as drug A) having an effect on?
proton pump inhibitor
inhibits H+/K+ATPase pump
inhibiting common pathway of histamine, gastrin, vagal stimulation of HCl
What is the acid base disorder that occurs from the underlying causal factor of Mallory Weiss syndrome?
vomiting
metabolic alkalosis
(high intra-abdominal/gastric pressure)
358: what are 3 common system anomalies found in cystic fibrosis?
1) sinopulmonary infections - pseudomonas aeruginosa, burkholderia capacia
2) pancreatic insufficiency
3) absent vas deferens
358: what is seen histologically in pancreatic insufficiency caused by cystic fibrosis?
distension and obstruction of pancreatic ducts
due to thickened secretions due to CFTR dysfunction
FA what are the adverse effects of Cimetidine (H2 blocker)?
P450 inhibitor
antiandrogenic
cross BBB
reduced renal creatinine excretion
FA name three H2 blockers
cimetidine
famotidine
nazatidine
‘dine’
(reversibly block H2 receptors - decreasing H+ secretion by parietal cells)
FA Do proton pump inhibitors reversibly or irreversibly inhibit H+/K+-ATPase in parietal cells?
irreversibly
‘prazole’
(omeprazole, lasoprazole, esomeprazole, pantoprazole, dexlansoprazole)
FA What are 3 adverse effects of PPI’s? i.e. omeprazole
pneumonia
acute interstitial nephritis
increased risk C Diff infection
fracture
B12 malabsorption
decreased Mg
FA Bismuth and Sucralfate bind to ______ to provide physical ______ allowing HCO3 secretion to re-establish ______.
ulcer base
protection
pH
FA sucralfate need an _______ environment
acidic
don’t give with PPIs/H2 (reduce acidity)
FA Bismuth is used to treat?
travellers diarrhoea
ulcer healing
(or quadruple therapy for H pylori)
FA Misoprostol is a _______ analog. It protects the ________ and reduces ________ production. It prevents __________-induced peptic ulcers
PGE1
mucosal barrier
acid
NSAID
FA Three actions of misoprostol are?
It is contraindicated in?
prevents ulcers
maintains PDA
ripens cervix
CI in childbearing potential women - (abortifacient)
FA octreotide is a _____________ analog. It inhibits splanchnic ____________ hormones.
somatostatin
vasodilatory
FA octreotide treats acute ____________, ____-oma and _________ tumours
acute variceal bleeds (decreases portal pressure)
VIPoma
carcinoid tumours
FA all antacids can cause?
hypokalaemia
FA aluminum hydroxide (antacid) causes?
CHOPS
constipation
hypophosphatemia
osteodystrophy
proximal muscle weakness
seizures
FA calcium carbonate (antacid) can cause?
hypercalcaemia
milk-alkali syndrome
rebound acid
FA calcium carbonate (antacid) can chelate and decrease the effect of drug ________?
tetracycline
FA magnesium hydroxide (antacid) can cause?
diarrhoea
hyporeflexia
hypotension
cardiac arrest
FA lactulose (osmotic laxative) can be used to treat?
hepatic encephalopathy
gut mictobiota degrade lactulose into lactic acid/acetic acid - promotes nitrogen excretion (trapping In colon)
FA odansetron is an ________ that works centrally as an antagonist of _______ receptor
antiemetic
5-HT3
FA metochlopramide is an ________ that works centrally as an antagonist of _______ receptor. Metochlopramide is a ____________ agent
antiemetic
D2
prokinetic
FA side effects of Metochlopramide can be?
extrapyrimidal symptoms
(tardive dyskinesia / parkinsonism) due to D2 receptor target
FA odansetron can interact with what drug?
digoxin
some diabetic medications
FA odansetron can cause what side effects?
QT interval prolongation
serotoinin syndrome
15049: what tests are used to identify clostridium difficile?
NAAT - polymerase chain reaction (PCR)
enzyme immunoassay - ID toxins or antigens
15049: what causes pseudomembranous colitis, and toxic megacolon with fulminant infection?
clostridium difficile
15049: What are the virulence factors of clostridium difficile?
toxins A and B
- damage enterocytes
- lead to watery diarrhoea
70: What are the main causes of cholesterol and black or brown pigment stones?
cholesterol stones - too much cholesterol (7a-hydroxylase ma contribute - but stones here usually only unconjugated bilirubin)
black stones - haemolysis
brown stones - infection - bacterial/injured tissure release b-glucuronidase
70: what is the consistency of cholesterol vs pigment stones?
What are the 5F’s of cholesterol stones?
cholesterol - yellow/grey + hard
pigment - black/brown + soft
5Fs: fat, female, fertile, forty, (fair)
8547: What does the left gastric vein anastomose with in the presence of oesophageal varices?
oesophageal vein
8547: name the 3 sets of porto-caval anastomoses …
oesophageal varices: left gastric - oesophageal
caput meducae: paraumbilical - superior/inferior epigastric
anorectal varices: middle/inferior rectal - superior rectal
1597: What cytokine has anti-inflammatory properties?
It is secreted by? _____ and _______
IL-10
Th2, Treg
8578: what conditions can induce hepatic encephalopathy (NH3 production and removal)?
increased NH3 production:
GI bleed - tissue injury -> protein breakdown -> ammonia metabolites increased
constipation
infection
decreased NH3 removal:
diuretics
renal failure
post-TIPS
8578: in hepatic encephalopathy, what will be elevated in astrocytes?
glutamine
normal astrocyte process:
Astrocytes take up glutamte present in synapses - undergoes condensation reaction with ammonia (NH3) via glutamine synthase to form glutamine (non-neuro active compound).
Then released by astrocytes and taken up by neurons where its converted back to glutamate (active neurotransmitter).
Excess ammonia - crosses BB - taken up by astrocytes -> increasing glutamine. Causes astrocyte swelling & decreased release.
1701: in pre-sinusoidal portal hypertension, will there be enlargement of the:
spleen
liver
ascites
spleen - yes
liver - no
ascites - no
portocaval anastamoses shunt blood in portal hypertesion
1701: acetaminophen toxicity does what to liver cells?
causes centrilobar hepatic necrosis
24-48hrs liver failure
1701: what does Budd Chiari do to liver cells?
causes centrilobar congestion and fibrosis
18541: Loperamide is an antagonist of _______ receptors and has poor penetration of ________.
mu-opioid receptors (u)
BBB
Treats diarrhoea
decreases gut motility
low addictive potential
(vs diphenoxylate - does cross BBB)
combined with LD atropine to reduce abuse
1875: why is the liver least vulnerable to infarction compared to other organs?
dual blood supply
portal vein and hepatic artery
usually copes well
unless supper hepatic artery in persons with liver transplant - collateral blood supply severed
15244: following an infection and subsequent watery diarrhoea - what should a child consume orally to replenish fluids?
hypotonic equimolar mixture of
sodium-glucose
osmotic gradient for water reabsorption established by - active co-transport sodium + glucose/chloride/amino acids
20428: What is the link between celiac disease and microcytic anaemia?
iron deficiency
celiac disease affects duodenum
iron is absorbed in duodenum
6510: what infection is pseudomembranous colitis seen in?
clostridium difficile
gram +, spore forming, anaerobic, toxigenic rod
6510: how would you describe gross and micro histology of pseudomembranous colitis?
White-yellow patchy pseudomembranes
neutrophil inflammatory infiltrate
fibrin, bacteria, necrotic epithelium
Toxin A and B -> disrupt cellular cytoskeletons and tight junctions -> colonocyte apoptosis
can lead to toxic megacolon (non-obstruction colon dilation) and perforation
