GI easter revision

Question 1

What does raised ALT and AST indicate?

Answer 1

Liver damage

Question 2

Which enzyme is most specific for liver damage?

Answer 2

ALT (not AST)

Question 3

Other than liver damage, when is AST raised?

Answer 3

Cardiac and skeletal damage

Question 4

When is ALP raised?

Answer 4

Damage to cells lining bile ducts (cholestasis = BD obstruction), bone mets, bone damage e.g. rickets, viral hepatitis

Question 5

What substances can be used as markers of hepatic synthesis?

Answer 5

Albumin, cholesterol, prothrombin time (many coag factors made in liver)

Question 6

How does hepatic conjugation of bilirubin change its structure??

Answer 6

Makes it water soluble so can be excreted in urine

Question 7

Patient has pale stool and dark urine with raised bilirubin…where’s the problem?

Answer 7

Pale stool = GI problem, dark urine = bilirubin has been conjugated by liver, so its post hepatic jaundice

Question 8

Patient has normal stool and dark urine with raised bilirubin- what’s the problem?

Answer 8

Normal stool means GI fine, dark urine means some conjugated bilirubin = hepatic jaundice

Question 9

Patient has normal stool and normal urine with raised bilirubin- what’s the problem?

Answer 9

GI fine so stool not pale, urine not dark because system too overwhelmed to conjugate = pre hepatic jaundice

Question 10

What LFTs are raised in pre, intra, and post hepatic jaundice?

Answer 10

Pre none, intra ALT, AST, post hepatic ALP and gamma GT

Question 11

What is murphy’s sign?

Answer 11

hypersensitivity to deep palpation in the subcostal area when a patient with gallbladder disease takes a deep breath

Question 12

What is the hepatic flexure?

Answer 12

The sharp bend between AC and TC!

Question 13

What is diverticulitis and where does it affect?

Answer 13

Small pouches form in the large intestine, L iliac pain common, mucus with faeces, constipation or diarrhoea, bloody stools, nausea.

Question 14

Causes of large bowel obstruction?

Answer 14

colorectal cancel, diverticulitis, IBD, femoral/inguinal hernias, sigmoid volvulus, faecal impaction

Question 15

If AST is disproportionately higher than ALT what cause does that suggest?

Answer 15

alcoholic liver disease

Question 16

Imaging signs of large bowel involvement?

Answer 16

Haustra which don’t go all the way across, >6cm dilatation

Question 17

Imaging signs of small bowel involvement?

Answer 17

valvulae convenientes go all the way across, dilatation >3cm, central location of bowel loops

Question 18

Small bowel obstruction causes?

Answer 18

Adhesions e.g. from previous surgery, malignancy, paralytic ileus

Question 19

Bowel obstruction presentation

Answer 19

Tinkling bowel sounds, constipation, hyperesonant percussion and abdo distension, peritonism and sepsis, N&V

Question 20

Pneumoperitoneum causes?

Answer 20

Peptic ulcers, IBD, diverticulitis, appendicitis, toxic megacolon, obstruction, malignancy, colonoscopy, post surgery, peritoneal dialysis

Question 21

Difference between plicae circulares and valvulae convenientes?

Answer 21

Plicae circulares are in the jejunum but not the ileum and help the chyme to spiral, valvulae convenientes are the lines that go all the way across SI

Question 22

How to clinically tell the difference between small and large bowel obstruction?

Answer 22

Small bowel vomits early and constipates late, large constipates early and vomits late

Question 23

Why is large bowel worse than small bowel obstruction?

Answer 23

Large bowel has the ileocecal valve so doesn’t let contents back into small bowel. Distention +++

Question 24

What is thumb printing?

Answer 24

Thickened haustra of large bowel from oedema/inflammation such as UC

Question 25

What is the coffee bean sign?

Answer 25

Sigmoid volvulus (cause of LB obstruction)

Question 26

Define toxic megacolon

Answer 26

Systemic toxicity with infectious colitis and dilated colon, complication of IBD, seen on scans as huge dilatation, oedema, pseudopolyps, thumbprinting

Question 27

What cells look after stem cells in intestinal crypts?

Answer 27

Paneth cells

Question 28

Glucose + glucose =

Answer 28

maltose

Question 29

Glucose + galactose =

Answer 29

Lactose

Question 30

Glucose + sucrose =

Answer 30

fructose

Question 31

Starch =

Answer 31

glucose + maltose + alpha dextrins

Question 32

What enzymes break down starch?

Answer 32

Amylase breaks down alpha1-4 neighbouring bonds and amylopectin breaks down alpha1-6 strand bonds.

Question 33

Taenia coli?

Answer 33

Three layers of longitudinal muscle found in the LI that form haustra when they contract

Question 34

What late complications can campylobacter cause?

Answer 34

found in uncooked poultry, can cause reactive arthritis or Guillain-Barre syndrome

Question 35

Likely cause of travellers diarrhoea?

Answer 35

Cyclospora- waxes and wanes for 3 weeks

Question 36

Pathology of coeliac disease?

Answer 36

Antibody to gliadin found in gluten causes T cell inflammation which destroys villi leading to total villous atrophy. This reduces absorption. Also undigested products then move through, attracting water to cause watery diarrhoea and also bacteria ferment to release methane and hydrogen.

Question 37

Causes of obstructive jaundice?

Answer 37

Pancreatic cancer (bile duct blocked so bile from liver can’t drain into GI), cholelithiasis

Question 38

When and what is faecal occult blood screening?

Answer 38

60-74yrs every 3 years for LB adenocarcinoma

Question 39

How to differentiate between L sided and R sided LB adenocarcinomas?

Answer 39

L sided (sigmoid and rectum) present with rectal bleeding and are quicker to present because poo more solid so obstructive, R sided (TC) present with occult bleeding and more advanced at presentation because bowel more distensible

Question 40

What is tenesmus?

Answer 40

Feel like need to poo but can’t go, associated with rectal cancers