Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Block 1 Week 3 > Normal Liver Physiology > Flashcards

Normal Liver Physiology Flashcards

1
Q

Approximately what percentage of the cardiac output goes to the liver?

A

25%.

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

The liver receives blood from which sources?

A
  1. Venous flow from the hepatic portal vein.

2. Arterial flow from the hepatic artery.

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

In the liver, hepatocytes are arranged in what structure?

A

Lobules

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

In the liver, what is in the centre of each lobule?

A

A central vein.

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

Describe venous blood flow through the liver starting at the portal vein.

A
  1. Portal vein
  2. Sinusoids
  3. Central veins
  4. Hepatic veins
  5. IVC
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Name the zones of the liver lobules going from outer to inner.

A

Zone I
Zone II
Zone III

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

In which zone of the liver lobules are hepatocytes most oxygenated?

A

Zone I.

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

What is another name for the hepatocytes in Zone I?

A

Periportal.

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

What is another name for the hepatocytes in Zone III?

A

Pericentral.

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

What functions do the hepatocytes in Zone I specialise in?

A
  1. Oxidative metabolism
  2. Gluconeogenesis
  3. Urea synthesis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What functions do the hepatocytes in Zone III specialise in?

A
  1. Drug metabolism
  2. Glycolysis
  3. Lipogenesis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What structure does blood flow through in the lobules of the liver?

A

Sinusoids

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

Which cells make up the walls of the sinusoids of the liver?

A

Sinusoidal endothelial cells.

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

What is a Kupffer cell’s function?

A

Phagocytosis and defence of the liver against bacteria. They are also involved in the breakdown of red blood cells.

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

What is the location of Kupffer cells?

A

In the sinusoids of the liver lobules.

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

What is the location of the Lipocytes of the liver? What is this space called where they are found?

A

They lie between the hepatocytes and the sinusoids in what is called the Space of Disse.

16
Q

List 8 functions of the liver.

A
  1. Production of bile
  2. Cholesterol processing
  3. Synthesis of plasma proteins
  4. Energy metabolism and substrate interconversion
  5. Drug metabolism and detoxification
  6. Immune functions
  7. Storage of vitamins and minerals
  8. Excretion of bilirubin
17
Q

List the 6 major components of bile.

A
  1. Bile salts
  2. Lecithin (a phospholipid)
  3. HCO3-
  4. Cholesterol
  5. Bile pigments
  6. Trace metals
18
Q

What 4 things do hepatocytes secrete?

A
  1. Bile salts
  2. Cholesterol
  3. Lecithin
  4. Bile pigments
19
Q

What 2 things do cholangiocytes secrete?

A
  1. Bicarbonate

2. Water

20
Q

What are bile acids?

A

Water-soluble derivates of cholesterol.

21
Q

What does conjugating bile acids with small molecules such as taurine and glycine do to them?

A

Makes them more soluble.

22
Q

What is Enterohepatic circulation?

A

The term enterohepatic circulation (EHC) denotes the movement of bile acid molecules from the liver to the small intestine and back to the liver.

23
Q

What percentage of bile salts are returned to the liver via the enterohepatic circulation? Of this percentage, what percentage are intact bile salts and deconjugated bile acids?

A

95%.

75% are intact bile salts, and 25% are deconjugated bile acids.

24
Q

Why would damage to the ileum, e.g. from Crohn’s disease or ileal resection, result in steatorrhoea?

A
  • It would impair the recycling of bile salts via enterohepatic circulation.
  • If the daily loss of bile salts exceeds the ability of the liver to synthesize new bile salts, the total circulating bile salt pool is diminished.
  • Bile salt deficiency leads to impaired fat digestion and absorption (via emulsion droplets and micelles).
  • Excess unabsorbed dietary fat is excreted in large, fatty and foul-smelling stools.
25
Q

The absorption of which vitamins is likely to be impaired with damage to the ileum?

A

Fat soluble vitamins - A,D,E, and K.

26
Q

What are the 4 main functions of bile salts?

A
  1. Emulsification of dietary lipids, rendering them accessible to pancreatic lipases, and presenting fat digestion products for absorption.
  2. Elimination of cholesterol.
  3. Prevention of cholesterol precipitation in the gallbladder.
  4. Facilitation of the absorption of fat-soluble vitamins.
27
Q

What percentage of cholesterol comes from diet and what percentage is synthesized by the body?

A

15% from diet

85% synthesized - mostly in liver

28
Q

List 6 roles of the liver in cholesterol processing.

A
  1. Synthesizes cholesterol from Acetyl-CoA.
  2. Synthesizes lipoproteins, which transport cholesterol in plasma.
  3. Exports cholesterol via circulation to body cells for synthesis of key products e.g. steroid hormones
  4. Utilises cholesterol for the synthesis of bile salts.
  5. Extracts excess cholesterol from plasma
  6. Exports excess cholesterol in bile for excretion in faeces.
29
Q

How is bilirubin formed?

A

From the breakdown of haem in the spleen and bone marrow.

30
Q

How do hepatocytes make bilirubin into a water-soluble molecule?

A

Conjugate it with glucuronic acid.

31
Q

What are bile pigments?

A

Excretory products being disposed of by the liver via the gut.

32
Q

Once in the small intestine what happens to conjugated bilirubin? What does this form? What percentage of this substance is excreted in the faeces? What happens to the remainder?

A

The conjugated bilirubin is digested by bacteria to form Urobilinogen - 90% of the Urobilinogen is excreted in the faeces. The remainder re-enters circulation where a small portion is excreted by the kidney.

33
Q

Which cells are found in the Space of Disse?

A

Lipocytes

34
Q

What type of molecule is Lecithin?

A

A phospholipid.

Block 1 Week 3 (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions