Liver

Question 1

Bile from liver can be hydrolysed by bacteria flora in GI tract into…?

Answer 1

Either
Urobilinogen which gets re-absorbed into blood to liver// excreted via kidneys

Or
Stercobilin& urobilin which are brown coloured and see excreted via faeces

Question 2

What’s the three main roles of liver in process of detoxification?

Answer 2

Modify or inactive hormones
Remove foreign toxic substances
Convert ammonia to urea

Question 3

Phases of Bio-transformation of drug/poisons (xenobiotics: substances not normally found in body)

Answer 3

Phase 1: modification by oxidation reduction or hydrolysis to reduce toxicity

Phase 2: conjugation to another molecule to increase solubility to facilitate excretion form body (toxins are insoluble)

Question 4

What are the chemicals that often conjugate to drugs/toxin?

Answer 4

Acetate, glururonic acid or sulphate

Question 5

What conjugated with paracetamol?

Answer 5

Cytochrome P450 –> N-acetyl p benzoquinone imine (NAPBQI) which is highly toxic ( product is more toxic than starting drug!)

Question 6

What’s a bile pigment? Is it soluble or not? What’s it’s purpose?

Answer 6

They are breakdown product of haem portion of haemoglobin (from senescent RBC, broken down by spleen, phagocytes)

Not soluble, need to be conjugated to glucorinic acid in liver

Responsible for yellow colour of bile

Question 7

Bile duct is lined by what cell

Answer 7

Hepatocytes

Question 8

Portal field (portal triad) is composed of?

Answer 8

Hepatic portal vein, hepatic artery, bile duct

Question 9

The flow of blood in liver

Answer 9

Portal vein and hepatic artery –> sinusoid –> central vein –> vena cava to heart

Question 10

Is flow of bile same direction as flow of blood?

Answer 10

No, counter current flow

Question 11

How does liver generate bile?

Answer 11

Na+ (bile salt )co transport (from sinusoid blood to hepatocyte)

Active transport of bile salt (from hepatocyte to bile canaliculi)

With sodium and water from bile canaliculi

Question 12

Blood sinusoid is lined by?

Answer 12

Single layer of fenestrated endothelial cells, small cells normal aggregated into groups called liver sieve plates

Question 13

Role of Kupffer cells

Answer 13

Also known as stellate macrophage.
Inside the lumen of sinusoid, adhere to endothelial cells.
Host defence function

Question 14

What are the 3 plasma protein that liver secrets? AGC

Their roles?

Answer 14

Albumin (transport lipids and steroid hormones)
Globulin (alpha, beta globulins, same role)
Clotting factor (fibrinogen, prothrombin)

Question 15

Where in blood, and in muscle does iron bind to? And what is it stored as?

Answer 15

In red blood cells, iron binds to haemoglobin
In muscle, iron binds to myoglobin, iron containing enzymes
Stored as ferritin

Question 16

As RBC senescent, iron is transferred by what plasma protein?
Or stored as what in where?

Answer 16

Transferrin

Stored as ferritin in liver

Question 17

Iron in blood can be stored, transferred by transferrin, and what else?

Answer 17

Erythropoiesis- production of RBC

Question 18

What’s liver’s endocrine function?

Answer 18

Releases insulin like growth factor (IGF) 1 and 2

Question 19

What are the functions of IGF?

Answer 19

Potent growth promoting effect

Question 20

What’s the Ph of hepatic bile?

Answer 20

7-8 isotonic

Question 21

What are the 4 components of bile

Answer 21

1. Bile salts
2. Bile pigments
3. Cholesterol
4. Lecithin

Question 22

Describe the process which bile salt formed?

Answer 22

Bile acid conjugated with amino acid like glycine form water soluble bile salt

Question 23

What’s the main role of bile salts?

Answer 23

Hydrophilic and hydrophobic regions form micelles, emulsification of fats

Question 24

Where does 95% od the bile salt go from intestine? Where does the 5% go?

Answer 24

Recycled back to liver via heptic portal vein

Lost in faeces

Question 25

What are the three form of bile salts after they are recycled back to liver?

Answer 25

1- unaltered
2- deconjugated, recycled back for reconjugation
3- modified by gut bacteria to secondary bile salts

Question 26

What’s CCK stands for?

Answer 26

Cholecystokinin

Bile- sac- move

Question 27

What type of hormone is CCK

Answer 27

Peptide hormone

Question 28

What happens when FA and protein in duodenum increase?

Answer 28

Increase in FA – increase in CCK – increase plasma CCK –
gall bladder contraction – increase bile flow in common bile duct – duodenum
Relaxed SOO- bile flow in duodenum

Question 29

Define xenobiotics

Answer 29

Sub NOT found in body

Question 30

What are the phase 1 and 2 of metabolism of liver?

Answer 30

Phase 1: modification via hydrolysis, oxidation, reduction

Phase2: conjugation to glucoronic acid, acetate

Question 31

What’s the process for aspirin metabolism?

Answer 31

Acetyl salicylic acid–> phase 1: salicylic acid –> phase 2: with glucoronic acid- salicylglucoronide

Question 32

Explain how does paracetamol overdose happen and produce toxic effect?

Answer 32

Normal conjugation reaction are saturated
Converted by cytochrome P450 (phase1) into N acetyl p-benzoquinone imine (NAPQI) which is highly toxic to liver and kidney p