Liver Function

Question 1

Blood is supplied to the liver by the _________ _________ and hepatic portal vein.

Answer 1

Hepatic artery

Question 2

______ flows from hepatocytes, via canaliculi and ductules, to form hepatic ducts.

Answer 2

Bile

Question 3

The liver is organised into functional units are called ___________.

Answer 3

Lobules

Question 4

What shape is each hepatic lobule?

Answer 4

Hexagon

Question 5

____________ are arranged into irregular, branching, interconnecting plates around the hepatic vein.

Answer 5

Hepatocytes

Question 6

Portal ________ lie at each ‘corner’ of the liver lobule.

Answer 6

Triads

Question 7

How do hepatocytes generate energy?

Answer 7

Oxidative phosphorylation and fatty acid phosphorylation

Question 8

____________ contain proteolytic enzymes.

Answer 8

Lysosomes

Question 9

What is the role of hepatic endoplasmic reticulum?

Answer 9

Bile acid synthesis and drug metabolism

Question 10

List two functions of the liver.

Answer 10

Bilirubin conjugation and protein synthesis

Question 11

List three functions of the Golgi complex.

Answer 11

VLDL production
Protein glycosylation
Albumin secretion

Question 12

Gluconeogenesis, glycogenesis and glycogenolysis, together with _________ ______ metabolism are major liver functions.

Answer 12

Fatty acid

Question 13

Name three substances that are detoxified and/or excreted by the liver.

Answer 13

Cholesterol, amino acid, and toxins

Question 14

Red cells are removed from the circulation by the ______________ _________ of the liver and spleen.

Answer 14

Reticuloendothelial system

Question 15

True or false: unconjugated bilirubin is insoluble.

Answer 15

True

Question 16

Unconjugated bilirubin is transported while bound to _________.

Answer 16

Albumin

Question 17

Unconjugated bilirubin can cross the blood-brain barrier, and is therefore potentially _________.

Answer 17

Toxic

Question 18

If not bound to albumin, unconjugated bilirubin is ______-soluble

Answer 18

Lipid

Question 19

Bilirubin is taken up by ____________ and conjugated (in ER) to mono- and diglucuronides.

Answer 19

Hepatocytes

Question 20

Normal bile is comprised of 25% _______________ and 75% diglucuronides.

Answer 20

Monoglucuronides

Question 21

Conjugated bilirubin is soluble, and is converted to _______________ by GIT bacteria.

Answer 21

Urobilinogen

Question 22

True or false: all urobilinogen is reabsorbed.

Answer 22

False

Question 23

Most urobilinogen is oxidised in gut to a brown pigment (______________) and excreted.

Answer 23

Stercobilin

Question 24

Unconjugated bilirubin is not filtered by the ______________.

Answer 24

Glomeruli

Question 25

If conjugated bilirubin is found in urine, this reflects an increase in plasma concentration, and is ________________.

Answer 25

Pathological

Question 26

___________ results when bilirubin > 50µmol/.

Answer 26

Jaundice

Question 27

Pre-hepatic jaundice is caused by _____________.

Answer 27

Haemolysis

Question 28

___________ jaundice, arises from failure of the conjugating mechanism, e.g., in the case of drugs, prematurity, hepatitis, etc..

Answer 28

Hepatic

Question 29

Post-hepatic jaundice occurs when the __________ ________ is blocked. such as with gall stones.

Answer 29

Biliary tract

Question 30

List three causes of unconjugated hyperbilirubinaemia.

Answer 30

Haemolytic disease of the newborn, increased bilirubin production, and due to low activity of conjugating enzymes at birth

Question 31

HDN carries a risk of ___________.

Answer 31

Kernicterus

Question 32

____________ _________________ is caused by leakage of bilirubin from hepatocytes or biliary system into the blood stream.

Answer 32

Conjugated hyperbilirubinaemia

Question 33

In conjugated hyperbilirubinaemia, bilirubin may be excreted in urine, forming a deep orange-_________ colour).

Answer 33

Brown

Question 34

Outline the principle of the chemical Diazo reaction.

Answer 34

Diazotised sulphanilic acid reacts with bilirubin to produce two azodipyroles. The reaction can be ‘accelerated’ to facilitate the reaction of unconjugated (indirect) bilirubin. Total bilirubin = indirect + direct bilirubin

Question 35

Bilirubin in infants can be measured directly by spectrophotometry, with no interference from ___________ and other pigments.

Answer 35

Carotene

Question 36

Fasting, morning sample is preferred to avoid ___________.

Answer 36

Lipaemia

Question 37

Bilirubin samples must be protected from ________.

Answer 37

Light

Question 38

When is fractionation indicated?

Answer 38

In neonates

Question 39

Obstruction in the biliary tract is termed '______________'.

Answer 39

Cholestasis

Question 40

Acute hepatocellular damage causes changes to ________________.

Answer 40

Aminotransferases

Question 41

Chronic liver disease can cause a decrease in albumin and ___________ time.

Answer 41

Prothrombin

Question 42

Both aspartate aminotransferase and alanine aminotransferase catalyse the interconversion of amino acids to 2-oxo-acids, by transferring _______ groups.

Answer 42

Amine

Question 43

The transaminase reaction is coupled to another reaction, such as ________ _____________, or lactate dehydrogenase.

Answer 43

Malate dehydrogenase

Question 44

Which enzyme has a reference range of 0-40 U/L?

Answer 44

Aspartate aminotransferase

Question 45

Which enzyme has a reference range of 0-45 U/L?

Answer 45

Alanine aminotransferase

Question 46

_________ consumption is measured as a change in absorption at 339 (340) nm, over several minutes.

Answer 46

NADH

Question 47

The difference in absorbance per minute is equal to NADH oxidised, and synonymous with __________ ________.

Answer 47

Enzyme activity

Question 48

Describe alkaline phosphatase.

Answer 48

Catalyses the hydrolysis of many substrates. Distributed widely, in the bone, placenta, kidney, etc.. Most serum ALP is derived from the liver and bone. Several isoenzymes exist, and they can be identified by electrophoresis. Increased in children and adolescents, but lower in adults. Raised especially in cholestatic liver disease, with a moderate or absent elevation in infectious hepatitis. 4-nitrophenyl is converted to 4-nitrophenoxide. Reference range is 35-104 U/L

Question 49

A peptidase, that catalyses the hydrolytic cleavage of peptides to form amino acids. Derived mostly from the liver. Elevated in all forms of liver disease. More sensitive than ALP and aminotransferases. References range for a female is 6-50 U/L, and for a male, 11-85 U/L is normal. To which enzyme does the passage refer?

Answer 49

y-glutamyl transferase

Question 50

_______________ is a feature of chronic liver disease, and severe acute liver disease.

Answer 50

Hypoalbuminaemia

Question 51

a-fetoprotein is used to investigate ____________ _____________.

Answer 51

Hepatocellular carcinoma

Question 52

What does prothrombin time measure?

Answer 52

Coagulation factors that are made by the liver

Question 53

All ___________ assays require a sufficient spectrophotometer, and standardisation and temperature are important.

Answer 53

Enzyme

Question 54

True or false: hepatic failure is a medical emergency.

Answer 54

True

Question 55

List two potential causes of hepatic failure.

Answer 55

Electrolyte imbalances and severe metabolic acid-base disorders

Question 56

The liver is a common site for _________ _________.

Answer 56

Tumour metastasis

Question 57

Wilson’s disease pertains to abnormal ________ metabolism.

Answer 57

Copper