Gastrointestinal 2

Question 1

functions of the liver

Answer 1

• Synthesis: Of albumin, growth factors, urea, coagulation factors, complement, c-reactive protein, specific binding proteins (iron, copper, vitamin A). Excretes bilirubin from RBC turnover.
• Storage: Of vitamins, glycogen, and lipids. Controls the absorption and transport of lipids (bile salts and lipoproteins)
• Metabolism: Biotransformation, Metabolizes amino acids, Regulates hormones: insulin, thyroxin, androgen, estrogen.
• Regulates blood glucose.

Question 2

what characterized non-alcoholic fatty liver disease?

Answer 2

excess lipid accumulation in the liver.

Question 3

frequency of non-alcoholic liver disease

Answer 3

40% in developed countries

Question 4

NAFLD is a major complication of ______ and _______

Answer 4

obesity and insulin resistance

Question 5

what can non-alcoholic fatty liver disease progress to?

Answer 5

• Progresses to NASH – Non-Alcoholic Steatohepatitis
  (Now is fat plus inflammation and scarring.)
• Cirrhosis (is a non-alcoholic cause of this)
• Which can then cause/develop into liver failure or hepatocellular carcinoma

Question 6

are there drugs available for NAFLD?

Answer 6

no but it is preventable and partially reversible

Question 7

components in the pathogenesis of NAFLD?

Answer 7

• Excess fatty acids in liver: from diet + adipose tissue +lipogenesis > metabolism + secretion
• Adipose tissue releases inflammatory adipokines like leptin that promote steatosis and fibrosis.
  (Release many pro-inflammatory that have a predominant effect on the liver.)
• Liver releases hepatokines that promote lipid accumulation and inflammation.
• Obesity alters intestinal microbiome and increases permeability: bacteria enter portal blood.
• Kupffer cells activate, release cytokines, initiate inflammation.
• Stellate cells activate, initiate fibrosis – so scarring in the liver.

Question 8

forms of bilirubin

Answer 8

• Bilirubin from normal turnover or RBCs is not water soluble and is bound to albumin for transport.
• Liver conjugates bilirubin to water-soluble glucuronides which are excreted in the bile.

Question 9

what is jaundice?

Answer 9

• Excess plasma level of either form of bilirubin can lead to tissue deposition: jaundice.
  o Yellow sclera is an obvious indicator – useful for someone with dark skin since melanin can mask the yellow in the skin.

Question 10

when does hemolytic jaundice occur?

Answer 10

• Occurs when there is a lot of bleeding.
• liver overloaded, so excess of unconjugated bilirubin, which is not water soluble.

Question 11

what happens in extrahepatic biliary obstruction?

Answer 11

• excess of conjugated bilirubin, which is water soluble, so can be excreted in urine.
• Intestinal bacteria normally convert a small fraction of the conjugated bilirubin to a brown pigment; so, obstruction can produce colorless stool – cannot go from the liver to the intestine.

Question 12

what can cause the obstruction in extrahepatic biliary obstruction?

Answer 12

o Congenital biliary atresia: born with a section that is not open.
o Stone
o Tumor that is compressing it
o Enlargement of a lymph node

Question 13

therapy for extrahepatic biliary obstruction

Answer 13

• Bile duct obstruction requires surgical correction.

Question 14

what is gilbert’s syndrome and what is the prevalence?

Answer 14

• intermittent jaundice due to reduced transcription glucuronyl transferase (UGT)
  (mutation in the promoter region of the UGT gene. still works but doesn’t work as well – high stress can trigger it.)
• Up to 10% of the population,
• symptom onset in early adulthood
  o more common in males.
• harmless

Question 15

how does neonatal jaundice occur and what is the therapy?

Answer 15

• newborn often have increased RBC hemolysis + lower synthesis of liver enzymes and albumin (still immature) + immature BBB,
• which allows free bilirubin to enter the brain with deposition in the basal ganglia and neuronal degeneration: Kernicterus.
  (Causes neurodegeneration in the basal ganglia – neural necrosis.)
• Prevented by treatment with blue light: photoconversion of bilirubin to a soluble derivative.

Question 16

incubation period for hepatitis?

Answer 16

weeks – months between exposure and illness.

Question 17

symptoms of viral hepatitis

Answer 17

o symptoms usually include fatigue, weakness, GI problems (nausea, vomiting, diarrhea, loss of appetite)
o may include fever, jaundice, and dark urine.
o B, C, and D can also cause skin rash, weight loss, joint pain, loss of inclination to smoke.

Question 18

Hepatitis viruses are very small so can squeeze through the ____________

Answer 18

sinusoid in the liver

Question 19

viral hepatitis is a risk factor for _____

Answer 19

HCC

Question 20

transmission of hepatitis A

Answer 20

• Transmission fecal-oral.
• Easily crosses intestine, so gets in the blood, liver, bile, and then stool, which can go in the water and contaminate it.
• Common in situations with poor hygiene, easily spread.

Question 21

progression of hepatitis A

Answer 21

Don’t have the capacity to cause a chronic disease.

Question 22

therapy for hepatitis A

Answer 22

vaccine for travel

Question 23

symptoms for hepatitis A

Answer 23

usually mild, usually fatigue, GI problems, fever.
Due to the immune response in the liver but it can be resolved.

Question 24

transmission of hepatitis B

Answer 24

• Highly contagious; virus in blood and all body fluids
• Major spread through sexual activity.

Question 25

life cycle and effect of hepatitis B

Answer 25

• Viral reproduction makes new virions plus non-infectious particles with only surface antigens, used as a “decoy” against the immune system.
• Immune response, both innate and adaptive, causes liver injury—immune reaction destroys hepatocytes to stop the spread of the virus.
• 90% of people recover.

Question 26

what happens when infants get hepatitis B

Answer 26

have lower immune defense and fewer symptoms, but most become carriers.

Question 27

progression of hepatitis B

Answer 27

• Can cause acute liver failure.
• Chronic infection is a major risk for cirrhosis and liver carcinoma.
• 10% become chronic asymptomatic carriers who spread disease and who often progress to cirrhosis.
• Primary liver disease almost always caused by this virus.

Question 28

therapy for hepatitis B

Answer 28

• Vaccination is now universal in Canadian children; but infection is still widespread in poor countries.
• 3 injections during 6 months (usually done in grade 4 in Canada)

Question 29

transmission of hepatitis C

Answer 29

Main route of transmission currently is IV drug use but can also be spread sexually.

Question 30

progression/life cycle of hepatitis C

Answer 30

• Majority progress to chronic disease with eventual cirrhosis (20% of people with chronic disease will progress) and significant risk of carcinoma.
• Increase in monocytes, fibrosis, and necrosis.
• Virus enters hepatocyte by attachment to CD81 and SRB1 (scavenger receptor) on cell surface, then is endocytosed.
• Virus reproduces in ER of hepatocyte, then attaches to a protective lipoprotein, makes a lipoviralparticle.
• Thought to protect it against immune system.
• Also helps it to easily be transported into the blood.
• It hijacks the hepatocyte synthesis of lipoproteins.

Question 31

therapy for hepatitis C

Answer 31

• Previous therapy was toxic with low success rate.
• Ability to now cure Hepatitis C (block reproduction) – need for liver transplant shifting to cirrhosis and cancer from NASH instead of Hepatitis C.

Question 32

transmission of hepatitis D

Answer 32

• Transmitted by bodily fluids.

Question 33

progression/life cycle of hepatitis D

Answer 33

• Delta virus.
• Requires Hepatitis B to produce the viral envelope.
• Requires its surface envelopes (takes the non-infectious particles).
• Superinfection produces severe symptoms: Causes the most severe chronic hepatitis due to greater immune response, leading to extensive necrosis

Question 34

therapy for hepatitis D

Answer 34

• No cure.
• Prevention: immunize against hepatitis B

Question 35

transmission of hepatitis E

Answer 35

• Transmission fecal-oral.
  o Epidemics in poor countries – contamination in water.

Question 36

most common subtypes of hepatitis E

Answer 36

• HEV 1 and 2 subtypes are the most common.

Question 37

effect of hepatitis E

Answer 37

• Recovery is the major outcome.
• Many are asymptomatic.
• Linked to neurological syndromes in a small fraction of patients.
• High risk in pregnancy: 20-30% death.
• Don’t have the capacity to cause a chronic disease.

Question 38

what does chole mean?

Answer 38

bile

Question 39

what does cystis mean?

Answer 39

bladder

Question 40

what does dochos mean?

Answer 40

duct

Question 41

what does lithos mean?

Answer 41

stone

Question 42

what are gallstones and the types?

Answer 42

• Ingredients in bile may precipitate within the gallbladder, producing stones.
• Composed of pigment (bilirubin salts), cholesterol, or a mixture.
• There are two major types: pigment and cholesterol gallstones. (Most are cholesterol (80%))

Question 43

gallstones are related/caused by ____

Answer 43

low fiber and high fat diet

Question 44

risks of gallstones

Answer 44

obesity, rapid weight loss, and chronic hemolysis

Question 45

what causes the pain of gallstones

Answer 45

related to irritation of gallbladder or progression through the bile duct

Question 46

treatment of gallstones

Answer 46

• often surgical – laparoscopic cholecystectomy (take gallbladder out).
• Another strategy is to try to dissolve the stone with shock waves

Question 47

potential complications of gallstones

Answer 47

• Acute cholecystitis:
  inflammation of gallbladder following obstruction, can cause obstructive jaundice., may be accompanied by infection. Elevated pressure may relocate the stone.
  Risk for abscess, perforation, peritonitis. Reversible with surgical correction.
• Choledocholithiasis (“bile/duct/stone”): causes cholestasis, (“bile/stops flowing”) and obstructive jaundice.
• Ulceration of gall bladder, fistula to duodenum.
• Pancreatitis, intestinal obstruction