Bile Flashcards

1
Q

How much bile is produced per day?

A

500ml each day

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What causes the yellow/green colour of bile?

A

Bilirubin and biliverdin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

how much bile do hepatocytes secrete?

A

60% of bile

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

How much bile are cholangiocytes responsible for secreting?

A

40%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

How is biliary excretion of bile salts and toxin performed?

A

Trough the use of biliary transporters on the apical and basolateral surfaces of hepatocytes and cholangiocytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the BSEP and what is the purpose of it?

A

Bile Salt Excretory Pump - Involved int he active transport of bile acids into the bile

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What transporters are MDR related proteins?

A

MRP1 and MRP2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What transports are the products of multi-drug resistance genes?

A

MDR1 and MDR3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is MDR1 used to transport?

A

excretion of xenobiotics and cytotoxins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are bile acids synthesized from?

A

Cholesterol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the two primary bile acids?

A
  1. Cholic acid

2. Chenodeoxycholic acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are the two secondary bile acids?

A
  1. Produced from cholic acid, is deoxycholic acid

2. Produced from chenodeoxycholic acid is lithocolic acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What causes the conversion of primary bile acids into secondary bile acids?

A

Gut bacterial enzymes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are bile acids conjugates with?

A

Glycine and taurine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are the primary functions of bile acids?

A

reduce the surface tension of fats and emulsify fats prior to their digestion absorbtion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is meant by the amphipathic nature of bile salts forming micelles?

A

They have hydrophobic domains on one surface and hydrophilic domains on the other surface

17
Q

Describe the organisation of a micelles?

A

1x surface hydrophilic domains (hydroxyl & carboxyl) - faces OUT → dissolves in water

2nd surface hydrophobic domains (nucleus & methyl) faces IN → dissolves in fat

FFAs & cholesterol INSIDE

18
Q

What happens to the sphincter of oddi between meals?

A

Sphincter of oddi is closed, and bile is diverted into the gal bladder for storage

19
Q

What happens to the sphincter of Oddi during eating?

A

The sphincter of Oddi relaxes which allows the secretion of bile into the duodenum

20
Q

What causes the gal bladder to contract?

A
  1. Gastic contents and acidic chyme enter into the duodenum and cause the release of CCK
  2. CCK binds to CCKa receptors and causes the gall bladder to contract, and release the stored bile into the intestine
21
Q

What else aside from CCK causes the contraction of the gall bladder?

A

Ach from the parasympathetic fibres of the vagus nerves

22
Q

What is the purpose of the gall bladder?

A

To store bile, concentrate it and acidify it

23
Q

What are some of the main components of bile?

A

Water, bile acids, bilirubin, inorganic salts, cholesterol, fatty acids

24
Q

Where is bilirubin produced from?

A

The breakdown of heme found in haemoglobin which is found in red blood cells

25
Q

How is free bilirubin transported around the body?

A

Bound to albumin

26
Q

What happens to the bilirubin as it enters the liver?

A

Bilirubin dissociates from albumin

Undergoes conjugation to form bilirubin diglucuronide - this is done through the conjugation with 2 x UDP-glucuronide molecules

27
Q

What happens to the bile which enters into the small intestine via the main duodenal papilla?

A

95% of the bile is absorbed into the terminal ileum through Na + / K+ ATPase pumps and Na+ / Bile co-transporters

28
Q

What happens to the 95% of the bile which is reabsorbed?

A

Taken back to the liver via the portal vein in the entero-hepatic circulation system

29
Q

What happens to the remaining 5% of bile which remains in the small intestine?

A

converted into secondary bile acids by gut bacteria

30
Q

What happens to the bilirubin after it enters into the intestine?

A
  1. Bilirubin -> Urobilinogen -> Stercobilinogen -> Stercobilin
31
Q

What happens to stercobilin?

A

Secreted out the GI systemas faeces - gives the faeces the distinctive brown colour

32
Q

What percentage of bilirubin is lost in the faeces?

A

85% is lost in the faeces as stercobilin

33
Q

How does bilirubin enter into the entero-hepatic circulation?

A

Bilirubin -> urobilinogen

urobilinogen is then taken back to the liver

34
Q

How does 1% of the bilirubin end up excreted in the kidneys?

A

bilirubin -> urobilinogen

urobiligenogen enters into the enterohepatic circulation and taken to liver

then transferred into systemic circulation and taken to kidney, along the way converted into urobilin, which is excreted in the kidney

35
Q

Describe the faeces and urine of patients with obstructive jaundice?

A

Faeces - pale - due to lack of sternobilinogen

Urine - darker due to bilirubin

36
Q

What is an ERCP?

A

Endoscopic retrograde cholangiopancreatography - is a procedure that combines upper gastrointestinal (GI) endoscopy and x-rays to treat problems of the bile and pancreatic ducts.

37
Q

What is a PTC?

A

Percutaneous transhepatic cholangiography - through common hepatic duct