Gastroenterology and GI Surgery Flashcards
radiologic finding of UC
lead pipe sign loss of haustra
HCV principle serological marker?
HCV-RNA
chronic gastritis divided into two subtypes
- chronic autoimmune gastritis (assoc pernicious anaemia and intestinal type gastric adenoma)
- chronic H. pylori gastritis
clinical features of haemochromatosis? (5)
- cirrhosis
- diabetes mellitus
- bronzed skin
- dilated cardiomyopathy and arrhythmia
- male gonadal atrophy
cellular mediator of Crohn’s disease?
Th1 cells
which HxV is particularly worrying in pregnancy? sequelae?
HEV fulminant hepatitis leading to liver failure and massive necrosis
complications of acute pancreatitis?
shock
pancreatic pseudocyst
pancreatic abscess
DIC and ARDS
pathoG - bilateral inflamed parotid glands
Mumps virus infection
pain following meal and weight loss in a smoker with hypertension?
ischaemic colitis - atherosclerosis of SMA
define tropical sprue
damage to the small bowel villi due to some unknown infectious agent resulting in malabsorption
GvHD pathogenesis of liver disease?
allografted T cells migrate into host tissues lymphocyte infiltration of intrahepatic bile ducts, recognition of host MHC I, granuloma formation intrahepatic biliary sclerosis, rise in Alk Phos, similar to PBC
RFs for colonic diverticula
constipation, straining low fibre diet
what bugs causes oesophagitis?
candida CMV HSV usually in the setting of HIV/AIDS, immunosuppression
diagnostic test for the major complication of UC?
AXR for toxic megacolon
2 consequences of a posterior duodenal ulcer
- penetration of the gastroduodenal artery causing severe haemorrhage
- acute pancreatitis
gross appearance of Crohn’s bowel? (3)
cobblestone mucosa, creeping fat and stricture
mechanism of lactulose in hepatic encephalopathy why not another laxative?
intraluminal conversion of lactulose (disaccharide) to acidic breakdown products converts ammonia to ammonium ions which cannot be absorbed. also decreases gut transit time. others do not acidify the stool
role of secretin in the GI tract
sitmulates pancreas in response to fat and acid arriving in duodenum
decreases gastrin production from gastric G cells and increases pancreatic juice (in.c bicarbonate) excretion from the pancreas.
peak age of CRC?
60-70
which HxV… travellers
HAV
how does newborn phototherapy work to reduce unconj bilirubin levels?
makes UCB water soluble so it can be excreted in the urine - it DOES NOT conjugate the UCB
failure of fusion of the facial prominences results in what condition?
cleft lip and palate
CA oesophagus upper 1/3rd spreads to which LNs?
cervical nodes
half life of albumin?
about 20 days
CRC serum tumour marker?
CEA only useful for assessing response to treatment, not for screening tool
Polyhydramnios drooling child vomit on first feed these findings suggest which pathology?
EA with TEF
Peutz-Jeghers syndrome genetic inheritance?
autosomal dominant
GvHD affects which three tissues primarily?
skin liver GI tract
Meckel’s diverticulum - rule of 2s (4)
2% of population
2 inches long within
2 feet of ileocaecal valve
presents in first 2 years of life
linear, shallow ulcerations in the lower oesophagus on gross morphology histology shows enlarged cells with intranuclear inclusion bodies where else can this disease affect?
CMV oesophagitis pneumonitis or colitis
6 features of colitis-associated carcinoma (epidem, gross, molecular, site affected, bonus)
- younger
- non-polypoid dysplasia
- histo: signet ring morphology, mucinous
- early p53 mutation
- proximal colon
- multifocal
what is the mechanism of cell damage in haemochromatosis?
Fe2+ generates oxygen free radicals via the Fenton reaction
why is a pancreatic pseudocyst not a real cyst? how long following acute pancreatitis does the pseudocyst take to “mature”?
not lined by epithelium but instead by fibrosis and granulation tissue 4 - 6 weeks, mature = formation of fibrous capsule
mouldy food associated with which cancer? how?
HCC mould = aflatoxin = G:C –> T:A muation in p53 = HCC
lymphatic drainage from above the pectinate line
internal iliac LNs
what is removed in the whipple procedure? (3)
- head and neck of pancreas
- proximal duodenum
- gallbladder
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how does Shigella invade the GI mucosa?
through endocytosis into the microfold (M) cells of the ileal Peyer patches
what are the AXR findings of oesophageal atresia?
gasless abdomen
3 associations with H pylori infection
- ulceration
- gastric adenocarcinoma
- MALT lymphoma
how is IBD related to gall stone formation?
occurs in Crohn’s disease when the terminal ileum is preferentially affected. This decreases bile acid absorption, leading to bile acid wasting. Phosphatidylcholine levels decreased. Cholesterol:bile acid ratio increases. Cholesterol stones precipitate
flattening of vili, crypt hyperplasia, increased intraepithelial lymphocytes on small bowel biopsy
Coeliac disease
2 complications of volvulus
- obstruction
- infarction (haemorrhagic)
on endoscopy a large, irregular ulcer with heaped up margins… what pathology?
intestinal type gastric CA
RFs for intestinal type gastric CA (3)
- intestinal metaplasia (chronic gastrites)
- nitrosamines in smoked foods
- blood type A
the layers of the gut wall from in to out? name the associated nerve plexus (when applicable)
mucosa submucosa (Meissner) muscularis externa (Auerbach, or Myenteric nerve plexus) serosa
a Mallory body is found where? what do they contain?
hepatocytes of alcoholic hepatitis contain damaged intermediate cytokeratin filaments
most common cause of delayed gastric emptying
uncontrolled DM
two mechanisms that prevent trypsin from autodigesting the pancreas
- SPINK1 - direct trypsin inhibitor
- trypsin auto-peptidase activity - cleaves itself. loss of auto-regulation by mutation at the cleavage site is responsible for hereditary pancreatitis
why is the left heart spared in carcinoid heart disease?
MAO present in the lung 5-HT coming from IVC so must pass through lung to get to left heart
procedure for secretin test for ZE syndrome
what is diagnostic?
administer secretin and monitor gastrin levels usually this causes a decrease in the production of gastrin but in gastrin-producing adenoma it will moderately increase gastrin production
clinical finding associated with metastatic liver cancer?
nodular enlarged liver on palpation of abdomen
hyperplastic polyps - benign or malignant? where do they commonly arrise?
benign rectosigmoid colon
3 factors contributing to development of cholelithiasis?
- supersaturation with cholesterol or bilirubin
- decreased production of bile salts or phospholipids
- stasis
obstruction of appendix in children? in adults?
kids - lymphoid hyperplasia adults - faecalith
how does a GI bleed lead to increased systemic nitrogen load?
haemoglobin bled into the lumen of GI broken down to aa’s –> ammonia –> portal circulation –> overwhelms liver
in the liver: microvesicular steatosis, fat vacuoles in cytoplasm.
EM findings - swelling and decreased number of mitochondria and glycogen depletion
suggests what pathology?
Reye syndrome
microbe causing sialadenitis
staph aureus
PBC is associated with which other conditions? (6)
- Sjögren
- Reynaud disease
- scleroderma
- thyroid (AI), Graves’ and Hashimoto.
- Celiac disease
what is Sister Mary Joseph nodule? association?
periumbilical metastasis intestinal type gastric CA
ulcer distal to the duodenal bulb suggests which pathology?
ZE syndrome
Rx Wilson disease
D-penicillamine (Cu-chelating agent)
zone 2, intermediate, of liver lobule is affected preferentially in which pathology?
yellow fever
pathoG linitis plastica
diffuse type gastric CA
extrusion of the abdominal contents through the abdominal folds; not covered by peritoneum or amnion this usually occurs where, relative to umbilicus?
gastroschisis typically to the right of umbilicus
cause of death in Crigler-Najjar syndrome?
Kernicterus
which enzyme catalyzes the rate limiting step of bile acid synthesis?
cholesterol 7alpha-hydroxylase
nutritional consequence of SIBO what goes up? what goes down?
up: Vitamin K, folate
down: Iron, B12, fat-soluble vitamins
a cystic tumour with lymphocytes and germinal centres of the parotid gland is called…
Warthin tumour
bowel sounds in the lower lung field suggests? complication?
paraoesophageal hernia left lung hypoplasia
a persistent herniation of abdominal contents into the umbilical cord is…
omphalocele
Barret’s oesophagus predisposes to which cancer?
oesophageal adenocarcinoma
two molecular pathways for the development of CRC? which is more common on which side of the bowel?
- adenoma-carcinoma development (left)
- microsatellite instability (Right)
high LES pressure on manometry suggests?
achalasia
where is the viral reservoir in latent oral herpes?
what is the virus?
trigeminal nerve root ganglion
HSV-1 (typically)
which gall stone is radiolucent?
cholesterol
anal fissure usually occurs where anatomically?
posterior - as this area is poorly perfused distal to the dentate(/pectinate) line
left versus right sided CRC features?
Left - napkin ring, decreased stool calibre, left sides pain, blood streaked stool
Right - raised lesion, IDA, non-specific pain
Peutz-Jeghers syndrome what/where are the skin lesions?
hyperpigmented macules oral mucosa, lips and genital skin
crypt abscess with neutrophils
UC
Behçet syndrome consists of a triad …
- aphthous ulcers
- genital ulcers
- uveitis
name the lateral, medial and inferior borders of Hesselbach’s triange
lateral - inferior epigastric artery
medial - lateral border of rectus abdominis
inferior - inguinal ligament
membranous GN is best associated with this HxV?
HBV
APC - adenomatous polyposis coli gene ocogene or tumour suppressor? Locus?
tumour supressor Chr 5
associated GI condition with Coeliac
small bowel carcinoma T cell lymphoma (enteropathy-associated T cell Lymphoma EATL)
in which secenario is HDV infection most dangerous?
superinfection on preexisting HBV, c/o co-infection with HBV
Leser-Trélat sign what is it? association?
solar keratosis eruption all over skin
gastric CA
which HxV is a DNA virus?
HBV
which liver tumour is associated with OCP use?
hepatic adenoma
what is damaged in Dubin-Jonhson syndrome?
conjugated bilirubin transport protein - cannot enter the bile cannaliculus
duodenal atresia clinical features? 2 symptoms, 1 radiological finding
- polyhydramnios
- bilious vomit
- double-bubble sign
derm association with coeliac disease? pathogenesis?
dermatitis herpetiformis IgA deposition at the tips of the dermal papillae, leading to vesicular blistering (herpetiform)
which HxVs predispose to HCC?
HBV, HCV, HDV
hirschprung disease association?
Down’s syndrome neural crest cell migration failure
pathogenesis of intussusception, what gives rise to the leading edge in children? In adults?
kids - lymphoid hyperplasia (many Peyer’s patches in TI) adults - tumour
which cell type mediates tissue damage in Coeliac disease?
Helper T cells Deaminated gliadin presented by APCs to Th cells
causes of pancreatitis
GET SMASHED
what is Sudan III stain? what does it test for? what is normal?
stool sample stain, most sensitive assay for generalised malabsorption unabsorbed dietary fats no fat in the stool at all
which colonic adenoma is most likely to undergo malignant change?
villous adenoma (villous is the “villain”)
UC complications acute or chronic
A: toxic megacolon
C: carcinoma
parenteral transmission of which HxV? (parturition, IVDU, sexual intercourse, transfusion)
HBV, HCV
cellular mediator of UC?
Th2 cells
which is the most common tracheoesophageal abnormality?
EA with TEF (OA with TOF)
chronic gastritis involving the body and the fundus suggests which pathology?
chronic autoimmune gastritis
granular eosinophilic ‘ground glass’ appearance - which HxV?
HBV
Peutz-Jeghers syndrome - risk of which CA (3)?
breast, CRC and GYN CA
most proximal portion of bowel affected in UC?
caecum can only affect large bowel!
zone 1, periportal, of liver lobule is affected preferentially in which pathologies?
viral hepatitis and ingested toxins (cocaine, halothane)
neurotoxic action of ammonia
decreases:
- aa transport across BBB
- glucose metabolism
- proper NT metabolism; overall more GABA and less glutamate
aetiology - newborn jaundice (physiologic)
transiently low UGT activity inherently, will increase in activity over time on their own
2 infective agents predisposing to gall stone formation? which type of gall stone is produced?
- ascaris infection (roundworm)
- clonorchis sinensis - China, Vietnam and Korea.. “Chinese liver fluke”
which HxV has faecal-oral transmission?
HAV, HEV
stimulation of parietal cells to produce acid (3)
enterochromafin cells produce histamine works on H2 receptor vagus nerve ACh gastrin from chief cells
chronic gastritis involving the antrum of the stomach suggests which pathology?
H pylori
FAP with malignant CNS tumour (medulloblastoma or glioma) is called…
Turcot syndrome
3 screening tests used to identify CRC
colonoscopy/flexi sigi faecal occult blood faecal immunochemical testing CT colonography
Rigler’s triad, suggestive of gallstone illeus is what?
evidence of SBO air/gas in the biliary tree gallstone at the ileocaecal valve
HNPCC preferentially affects which area of bowel?
proximal colon
causes of chronic pancreatitis? (2)
adult - alcoholism kids - cystic fibrosis
which HxV… contaminated water or undercooked seafood
HEV
major RFs for HCC?
- chronic hepatitis
- cirrhosis (of any cause)
- afltatoxin derived from aspergillus
primary tumour marker for HCC?
alpha-fetoprotein
most common cause of death in cirrhotic patients?
ruptured oesophageal varyx
Rokitansky-Aschoff sinus - herniation of gallbladder mucosa into the muscular wall … suggests which pathology?
chronic cholecystitis
most common site of bowel angiodysplasia?
caecum and right colon due to high wall tensions
what marks the development into chronic pancreatitis from recurrent acute pancreatitis?
pancreatic insufficiency - fat soluble vitamin deficiency (A,E,D,K) - steatorrhoea
gross and histologic examination of bowel mucosa for primary lactase deficiency?
normal
risk factors for acute gastritis (6)
- severe burn (Curling ulcer) and subsequent hypovolaemia, hypoperfusion
- NSAIDs (PGE2 inhibition)
- alcohol
- chemotherapy
- increased ICP (Cushing ulcer) - increased vagal stimulation, increase ACh
- Shock
radiologic finding of Crohn’s
string sign
Gilbert syndrome inheritance?
AR
how does portal hypertension (NOT liver failure) alter platelet function?
spenomegaly, hypertrophy, increased splenic sequestration, decreased circulating Plts
essential mixed cryoglobulinaemia …which HxV?
HCV
most likely type of CA from distal oesophagus
adenocarcinoma
bowel histopath - lymphoid aggregates with granuloma
Crohn’s disease
complications of Crohn’s disease (4)
- malabsorbtion
- calcium oxalate stones
- fistula
- carcinoma (only with colon involvement)
HLA subtypes associated with Coeliac disease
HLA DQ2 and DQ8
duodenal atresia is associated with which condition?
Down’s syndrome
on biopsy, 3 factors increasing carcinoma risk in a polyp?
- size >2cm
- sessile growth (c/o pedunculated)
- villous histology (‘the villain’ of CRC)
diverticulosis complications - immediate, acute, chronic
I - haematochezia A - diverticulitis C - fistula
HNPCC - genetic mechanism?
mutation in DNA mismatch repair enzymes
RFs for bilirubin stone formation?
- extravascular haemolysis
- biliary tract infection
failure to pass an NG tube into stomach at birth suggests which pathology?
oesophageal atresia
associated disease causing achalasia? why?
Chagas disease, infection with trypanosoma cruzi damage to the myenteric plexus of the oesophagus, cannot coordinate peristalsis or relax the lower oesophageal sphincter
what small bowel infarction is seen in hypotension?
mucosal infacrtion mucosa (inner layer) is furthest from the blood supply, greatest diffusion distance
adult onset asthma suggests what disease?
GORD
duodenal atresia - association?
Down’s syndrome
Strep bovis endocarditis - association?
CRC must follow up with colonoscopy, FOB & tumour markers
antibody present with PBC?
AMA
intestinal biopsy: foamy macrophages laden with PAS +ve granules in the lamina propria suggests which pathology? common tissues affected? (4)
Whipple’s disease. small intestine, joints, CNS, heart
signet ring cells that diffusely infiltrate the gastric wall… what pathology?
diffuse type gastric CA
what happens to serum Ca in acute pancreatitis
hypocalcaemia saponification consumes Ca from serum in fat necrosis. Sign of poor prognosis
which HxV is most likely to lead to chronic hepatitis? which has a 20% chance?
HCV 20% = HBV
GP setting - 42 y/o man had a father die of CRC aged 57. When should he start screening, and which test?
colonoscopy from 47 years old (or 10 years before relative developed CA)
chronic sequela of biliary atresia?
cirrhosis
periductal fibrosis with onion-skin appearance?
PSC
biopsy of colonic polyp shows: high grade dysplasia, long glands with villi-like projections from the surface. Gross - velvety, cauliflower-like appearance
villous adenoma
5 risk factors of pancreatic CA?
- chronic pancreatitis (duration dependent)
- smoking
- age
- diabetes mellitus (duration dependent)
- genetic predisposition (hereditary pancreatitis, HNPCC, FAP, MEN syndromes)
consequence of anterior duodenal artery
perforation into the anterior abdominal cavity, causing pneumoperitoneum
2 features of vitamin E deficiency
- haemolytic anaemia
- peripheral myoneuropathy - oxidative damage to long nerve cells and high oxidative stress erythrocytes
most common type of stone?
cholesterol stone (90%)
other than CB, in bile duct obstruction what else leaks into the blood?
- cholesterol (xanthoma)
- bile salts (pruritus)
tumour marker for pancreatic CA?
CA 19-9
gene mutations associated with Lynch (HNPCC) syndrome?
MSH2, MSH6 MLH1 PMS2
pathoG - hypertrophy of Brunner glands
peptic ulcer disease - duodenal ulcer
association with UC
PSC positive pANCA (microscopic polyangiitis, Churg-Strauss…)
macrovesicular steatosis - which HxV?
HCV
FAP natural history of disease?
development of 100s to 1000s of polyps develop CA before age 40. must have prophylactic colectomy with ileorectal anastomosis or proctocolectomy
pathogenesis of foetor hepaticus
portal hypertension portosystemic shunting allows passage of thiol toxins through the lungs into the breath
main cellular mediator of PBC?
T lymphocytes
key finding in Dubin-Johnson syndrome on gross histology?
pitch black liver
a white plaque discolouration on the inside of the mouth that cannot be scraped away - what is this? associated condition?
leukoplakia oral SCC
foamy macrophages in the lamina propria suggests..?
whipple’s disease
2 associations with oesophageal web?
- plummer vinson syndrome (IDA)
- oesophageal SCC
a white deposit on the tongue easily scraped away with tongue depressor - what is this? associated condition?
oral candidiasis immunocompromised state
4 steps in the adenoma-carcinoma sequence (molecular progression from normal colonic mucosa to adenomatous polyp to CA)
- APC inactivation (Two-hits) - increase risk of developing polyp)
- K-ras mutation leads to polyp developing
- p53 oncogene mutation AND
- increase COX expression –> carcinoma
coffee bean sign suggests what pathology?
sigmoid colon volvulus common in the elderly
CA oesophagus middle 1/3rd spreads to which LNs?
mediastinal or tracheobronchial
air or stool in the urine suggests?
diverticulosis with colovesicular fistula formation
Acute HBV hepatitis clinical features?
- fever/fatigue/jaundice/transaminitis (as all others)
- joint pain
- urticarial widespread rash
association with Crohn’s
ARTHRITIS (Ank Spond, sacroilitis, migratory polyarthritis)
derm: erythema nodosum, pyoderma gangrenosum
ocular: uveitis
what is a porcelain gall bladder? which pathology? increases risk of which cancer?
shrunken, hard gall bladder due to chronic inflammation, fibrosis and calcification chronic cholecystitis gallbladder adenocarcinoma
the portal triad consists of? contained within which structure?
hepatic artery proper hepatic portal vein common bile duct hepatoduodenal ligament
air in the mediastinum and subcutaneous emphysema suggests? association?
Boerhaave syndrome
Mallory-Weiss syndrome
parietal cells make what in the stomach?
acid intrinsic factor
in hepatic fibrosis and portal hypertension, where do varices form?
oesophagus umbilicus (caput medusae)
Rectum (anorectal varices)
3 groups of clinical features from cirrhosis
- decreased toxin clearance
- portal HTN
- decreased synthetic funciton
embryonic origin of Meckel’s diverticulum
failure of vitelline duct to involute COMPLETELY
clinical features of abetalipoproteinaemia (2)
malabsorption (cannot make chylomicrons) absent LDL or VLDL in plasma
FAP with desmoid tumours of the retroperitoneum and osteoma, hypertrophy of retinal pigment epithelium and impacted teeth is called…
Gardner syndrome
what is Krukenburg tumour? Association?
bilateral ovarian metastasis diffuse type gastric CA
CA oesophagus lower 1/3rd spreads to which LNs?
celiac and gastric
Wilson disease gene mutation
ATP7B gene (ATP-dependent copper transporter)
polyarteritis nodosa & aplastic anaemia …which HxV?
HBV
molecular mechanism of cell damage in Wilson disease?
Copper deposition in target tissues, hydroxyl-free radical production
first enzyme activated in acute pancreatitis?
trypsin –> activates all other enzymes
a rough, shaggy, white patch of discolouration on the lateral aspect of the tongue - what is this? associated condition?
hairy cell leukoplakia immunocompromise & subsequent infection wtih EBV, causing squamous mucosa hyperplasia (not pre-malignant)
FAP muation?
APC on chromosome 5
primary haemochromatosis gene mutation?
HFE, usually C282Y (cystine -> tyrosine)
biopsy of colonic polyp shows: small, pedunculated polyp of dysplastic cells forming tube-shaped glands
tubular adenoma
HNPCC - risk of which CA (3)?
CRC ovarian endometrial
2 types of necrosis in acute pancreatitis
- liquefactive necrosis
- fat necrosis (saponification of peripancreatic fat)
What is present in the duodenum that activated pancreatic enzymes? which enzyme is activated first?
duodenal brush border expression of enteropeptidase(/enterokinase) activates trypsin from trypsinogen
2 complications of GORD
- ulceration with stricture
- Barret oesophagus
most common oesophageal cancer in the world?
squamous cell carcinoma
sickle cell disease predisposes to which biliary condition?
bilirubin gall stones
most and least common sites of involvement in Crohn’s disease
most - terminal ileum least - rectum
why is AST > ALT in alcoholic liver damage?
AST held within mitochondria and acetaldehyde is a mitochondrial poison
a mobile, painless, well circumscribed mass at the angle of the jaw cause for concern?
pleomorphic adenoma from parotid gland no - likely benign, though high rate of recurrence
Rx surgical resection
time cut off between acute and chronic hepatitis?
6 months
which is worse? leukoplakia or erythroplakia?
erythroplakia due to highly vascularised giving red colour. more predictive of dysplasia
Classic antibodies for coeliac disease?
IgA vs endomysium, tTG or gliadin higher proportion of IgA deficiency so must also test for IgG
most affected area(s) of the small bowel?
jejunum (folate def) ileum (B12 def) c/o coeliac
acute cholecystitis 2ary gall stone… most common pathogen?
E Coli
most common nidus of H Pylori infection?
prepyloric antrum of stomach
which clotting study best used to follow natural history of cirrhosis?
PT following enzyme function of liver epoxide reductase (target of warfarin)
complications of chronic pancreatitis (2)
- 2ary type 1 DM
- pancreatic carcinoma arising from pancreatic ducts
most affected area of bowel on Coeliac disease?
duodenum
most likely type of CA in proximal 2/3rds of oesophagus
squamous cell carcinoma
in cirrhosis, which is the key cel mediating fibrosis? which cytokine is implicated?
stellate cell TGF-beta
zone 3, pericentral vein, of liver lobule is preferentially affected in which pathologies?
alcoholic hepatitis ischaemia metabolic toxins (as contains P450 system)
through which GI layer must an EROSION pass in order to be called an ULCER?
muscularis mucosa (just below the mucosal layer, above the submucosa)
membranoproliferative GN is best associated with which HxV?
HCV
annular pancreas complication?
duodenal obstruction
OCP use association with which GI cancer?
hepatic adenoma benign - will regress upon cessation of drug
Mumps complications (3)
- orchitis and subsequent sterility (only teenagers)
- pancreatitis (amylase is not an indicator with mumps infection b/c salivary glands also release it)
- aseptic meningitis
FBC finding of hypersplenism?
anaemia thrombocytopenia
lymphatic drainage from below the pectinate line
superficial inguinal LNs
failure of ventral wall rostral fold closure leads to what?
ectopia cordis (sternal defects)
failure of ventral wall lateral fold closure leads to what?
omphalocele, gastroschisis
ventral wall caudal fold closure leads to what?
bladder exstrophy
double bubble sign suggests what?
associated with what congenital condition?
duodenal atresia
Down’s syndrome
what is the pathogenesis of jejunal/ileal atresia?
disruption of mesenteric vessels, ischaemic necrosis, segmental resorbtion
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pyloric stenosis associated with in utero exposure to what drug?
macrolide antibiotics
what segment of developing gut is the pancreas from?
foregut
retoperitoneal structures
Suprarenal (adrenal)
Aorta and IVC
Duodenum (2nd & 4th parts)
Pancreas (except tail)
Ureters
Colon (ascending and descending)
Kidneys
Esophagus (thoracic)
Rectum
falciform ligament
connects and contains?
liver to ant abdominal wall
ligamentum teres hepatis
hepatoduodenal
connects and contains
liver to duodenum
portal triad: proper hepatic artery, hepatic portal vein, common bile duct
(red, green, blue)
gastrohepatic
connects and contains
liver to lesser curvature of stomach
gastric ateries
gastrocolic ligament
connects and contains
greater curvature of stomach to transverse colon
gastroepiploic arteries
gastrosplenic ligament
connects and contains
greater curvature of stomach to spleen
short gastrics, left gastroepiploic artery
splenorenal artery
connects and contains
spleen to posterior peritoneum
splenic artery and vein; tail of pancreas
where do you find Brunner glands and what do they do?
duodenum; submucosa
bicarb secretion
what are Peyer patches and where do you find them?
lymphoid aggregates/tissue in the lamina propria/submucosa
ileum
who gets superior mesenteric artery syndrome and why?
low BMI/malnutrition
less adipose tissue between SMA and 3rd horizontal portion of duodenum
spleen arises from what germ layer?
mesoderm
draw the coeliac trunk
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what is the portosystemic anastamosis affected in caput medusae?
paraumbilical veins (become distended)
shunt blood back to small epigastric veins
what is the portosystemic anastamosis affected in anorectal varyx?
superior rectal (proximal to dentate line)
shunts blood to middle and inferior rectal veins
what anal cancer do you get above the dentate line?
adenocarcinoma
what anal cancer do you get below the dentate line?
squamous cell carcinoma
arterial supply above and below the dentate line
above - superior rectal from IMA
below - inferior rectal from pudendal
what nerve gives perianal sensation below the dentate line (i.e. affected in external haemorrhoids)
inferior rectal, branch of pudendal n.
what are the layers of the spermatic cord?
what are the linings of the abdominal wall that they correspond to?
- internal spermatic fascia - transversalis fascia
- cremaster - internal oblique
- external spermatic fascia - aponeurosis of external oblique
what is the anatomic space through which a direct inguinal hernia protrudes?
what are the borders?
Hesselbach triangle
lateral - inferior epigastric vessels
medial - lateral wall of rectus abdominis
inferior - inginal ligament
meconium discharge from umbilicus soon after birth is suggestive of …
persistent vitelline duct
pathoG
99mTc-pertechnetate scan showing collection in the right lower quadrant
Meckel diverticulum
the ventral pancratic duct gives rise to what normally?
uncinate process, main pacreatic duct, portion of head of pancreas
venous drainage of internal haemorrhoids
superior and middle rectal vein
inferior mesenteric vein and internal iliac respectively
venous drainage of external haemorrhoids
inferior rectal vein
internal pudendal, internal iliac vein
what are the layers of GI wall present in Meckel’s diverticulum?
True diverticulum so it contains all of the layers
mucosa, submucosa, muscularis and serosa
gastric varices isolated to the fundus of the stomach suggests what?
splenic vein thrombosis
2ary to pancreatitis, pancreatic CA or other abdominal tumours
what structure separates the duodenum from the jejunum?
ligament of Treiz
gastrin
function and secretion site
increase gastric H+ secretion
G cells of gastric antrum and duodenum
somatostatin
function and site of secretion
decrease secretion of all other gut hormones
D cells of pancreatic islets and gut mucosa
cholecystokinin
function and site of secretion
gall bladder motilityl, secretion of pancreatic enzymes, HCO3- secretion
I cells of small intestine
secretin
function and site of secretion
increase HCO3- production from duodenum and pancreas, pancreatic enzyme release, decrease gastric H+ secretion
S cells of duodenum
GIP
function and site of secretion
stimulate insulin release, decrease gastric H+ secretion
K cells of small intestine
motilin
function and site of secretion
increase gut motility
M cells of small intestine
what is the GI effect of erythromycin and what is the mechanism?
diarrhoea
activation of the motilin receptor in the stomach and duodenum
what are P450 inducers?
NEURO: carbamazepine, barbs, phenytoin, modafinil, St John’s Wort
ID: rifampin, griseofulvin
Immuno: cyclophosphamide
what are P450 inhibitors?
ID: isoniazid, ritonavir, fluoroquinolones, azole antifungals, clarithromycin
cardio: amiodarone
gastro: cimetidine (histamine antagonist for PUD)
other: grapefruit juice
what is the acetylcholine receptor present on parietal cells that controls gastric acid secretion? stimulation of this results in what?
M3
stimulation = gasric acid release
what is cimetidie?
what is the main limitation of this drug?
treatment for GORD/GERD - zantac
inhibitor of H2 receptor. effective in preventing gastric acid release in response to gastrin/histamine release, but no effect on vagal gastric acid secretion which is mediated through M3 receptors
what is diphenoxylate?
opioid anti-diarrhoeal
binds mu-opioid receptors, decreases GI motility
what enzyme is inhibited by fibrate antitriglyceridaemic drugs that promotes formation of gall stones?
cholesterol 7-alpha hydroxylase