1: Physiology and pharmacology of the liver Flashcards Preview

Gastrointestinal Week 6 2016/17 > 1: Physiology and pharmacology of the liver > Flashcards

Flashcards in 1: Physiology and pharmacology of the liver Deck (48)
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1
Q

The liver is involved in the ___ of carbohydrates, fat and protein.

A

metabolism

2
Q

Where do gluconeogenesis, glycogenolysis, glycogenesis and the urea cycle take place?

among a million other processes

A

Liver

3
Q

Where are hormones degraded?

A

Liver

4
Q

Which hormone is converted from its inactive to active form in the liver?

A

Thyroxine to Triiodothyronine

(T4 > T3)

5
Q

Which vitamin is activated in the liver?

A

Vitamin D

6
Q

Which three types of molecules does the liver store?

A

Vitamins

Metal ions (e.g copper and ion)

Glycogen

7
Q

What is a protein marker of liver function?

A

Albumin

8
Q

Which molecules, involved in coagulation of blood, are synthesised in the liver?

A

Factors

9
Q

Albumin is a marker for ___ function.

A

liver

10
Q

What phagocytic cells are found in the liver and destroy debris and bacteria?

A

Kupffer cells

11
Q

The liver detoxifies substances found in the ___.

Give two examples.

A

blood

Drugs, alcohol

12
Q

Where is bile produced?

Where is bile stored?

A

Liver

Gall bladder

13
Q

Through which sphincter is bile released? Where does this sphincter lead?

A

Sphincter of Oddi

2nd part of the duodenum

14
Q

What event prompts the gall bladder’s smooth muscle to contract?

Which signal molecule is involved?

Which parasympathetic nerve is also involved?

A

Chyme in the duodenum

CCK

Vagus nerve

15
Q

Which signal molecule is released during a meal and prompts the Sphincter of Oddi to open?

A

CCK

16
Q

Bile is involved in the digestion and absorption of ___.

A

fat

17
Q

What component of bile can crystalise to form a gall stone?

A

Cholesterol

18
Q

Which antibody is found in bile?

A

IgA

19
Q

Which breakdown product of red blood cells is found in bile?

Excess amounts of this product in the blood cause ___.

A

Bilirubin

jaundice

20
Q

What is cholelithiasis?

A

Gall stones IN THE GALL BLADDER

21
Q

Where do gall stones most commonly appear?

A

Gall bladder

Common bile duct

22
Q

What is the most common pathology of the biliary tract?

A

Cholelithiasis

23
Q

What surgical technique is used to treat symptomatic cholelithiasis?

A

Laparoscopic cholecystectomy

keyhole surgery to remove the gall bladder.

Why not ERCP? because ERCP can only remove gall stones in the bile duct

24
Q

If cholelithiasis isn’t producing symptoms, how may it be treated (instead of cholecystectomy)?

A

Ursodeoxycholic acid (dissolves the stones)

25
Q

What is biliary colic?

A

Colicky abdominal pain caused by a gall stone blocking the bile duct

26
Q

Which drugs can be used to relieve pain caused by biliary colic?

A

Atropine

GTN

27
Q

Which process reabsorbs 95% of the bile salts entering the terminal ileum from the duodenum?

A

Enterohepatic recycling

28
Q

If bile salts aren’t reabsorbed by the terminal ileum and returned to the liver, how does the body synthesise it?

A

Using cholesterol

29
Q

Which drugs can be used to treat hyperlipidaemia and cholestatic jaundice by blocking bile salt reabsorption?

A

Bile acid sequestrants

30
Q

Name a bile acid sequestrant used to reduce cholesterol levels.

A

Cole–

colesevelam, colestipol, colestyramine

31
Q

Colesevelam binds to ___ ___ in the terminal ileum, preventing their reabsorption and forcing the body to break down ___ to replenish it.

A

bile salt

cholesterol

32
Q

What are the side effects of bile acid sequestrants e.g colesevelam?

A

Vitamin deficiency (bind to fat-soluble vitamins and block absorption)

GI side effects (constipation, diarrhoea, pain, bloating)

Tastes awful

33
Q

The liver usually converts ___ drugs to ___ metabolites.

(inactive , active)

A

active drugs to inactive metabolites

34
Q

Which drug gains activity when it is metabolised by the liver?

A

Codeine

turns into morphine.

35
Q

Sometimes, liver metabolism leaves the activity of a drug ___.

A

unchanged

36
Q

What tends to happen in Phase I of drug metabolism?

A

Some reaction to make it more polar (less active)

e.g oxidation, reduction, hydrolysis

37
Q

What tends to happen in Phase II of drug metabolism?

A

A functional group is attached to the polar drug to render it even more polar

38
Q

What happens to a drug once it has been rendered polar by liver metabolism?

A

Excretion

39
Q

Which family of enzymes control oxidation reactions in Phase I of drug metabolism?

A

Cytochrome P540 monooxygenases

(CYP enzymes)

40
Q

___ is a component of the R groups in many amino acids.

A

Nitrogen

41
Q

High levels of nitrogen is ___ to cells.

A

toxic

42
Q

____ is detoxified by the liver to form ___, which is secreted in the urine.

A

Ammonia

urea

43
Q

What disease occurs when the liver cannot detoxify ammonia to urea?

A

Hepatic encephalopathy

44
Q

What is the end stage of hepatic encephalopathy?

A

Hepatic failure

Coma

Death

45
Q

In hepatic encephalopathy, blood levels of ___ are high.

A

ammonia

46
Q

Ammonia is also produced by ___ in the gut.

A

bacteria

47
Q

Which drug is used to convert ammonia produced by bacteria into safe ammonium?

A

Lactulose

48
Q

Which drugs can be used to kill off ammonia-producing bacteria in hepatic encephalopathy?

A

Antibiotics