Brainscape's Knowledge GenomeTM

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


See full index

NUT1005 > The Liver > Flashcards

The Liver Flashcards

1
Q

What are the two major vessels that supply the liver

A

Hepatic artery and hepatic portal vein

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

Describe the movement of blood in the liver

A

High blood flow and low vascular resistance

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

What does the hepatic portal vein carry

A

Water soluble products of digestion absorbed from enterocytes into the villi capillaries

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

What is the basic functional unit of the liver

A

The liver lobule

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

Describe the structure of a lobule

A

Consists of hepatic cellular plates (2 cells thick) and has a central vein ( branch of hepatic vein carrying blood to IVC) in centre, blood flows between hepatocytes via sinusoids (capillaries) and small bile canaliculi that empty in to bile ducts lie between adjacent cells

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

What is a triad in a lobule

A

At the corner of each lobule a triad of 3 vessels exist as branches of the portal vein, hepatic artery and bile duct

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

What are Kupffer cells

A

Macrophages within the liver

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

What are the 3 main types of cells that the liver consists of

A

Hepatocytes, endothelial cells and kupffer cells

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

What is the function of the liver

A

Energy metabolism and storage

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

What 8 processes are controlled by the liver

A

Glycogenesis, gkycogenolysis, gluconeogenesis, lipogenesis, lipolysis, transanimation and deanimation and excretion

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

Why must the liver maintain a store of glucose (glycogen store)

A

Glucose cannot be synthesised directly from fat stores in the liver

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

How does circulating glucose enter liver cells

A

GLUT-2 glucose transporter

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

How is glucose store in cells

A

As granules

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

How are TAG carried in the blood

A

Hydrophobic so carried as lipoproteins (bound to protein albumin)

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

What are drawbacks of glucose and protein storage

A

Carry large weight penalty

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

What is the rate of glucose turnover

A

2mg/kg/min

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the rate of fatty acid turnover

A

1.7 mg/kg/min

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

How much energy does glucose yield (kJ/g)

A

17

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

How much energy does fatty acids yield (kJ/g)

A

38

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What % of total contribution to energy is from glucose

A

32%

21
Q

What % of total contribution to energy is from fatty acids

A

66%

22
Q

What hormones are released from the pancreas into the hepatic portal vein

A

Insulin and glucagon

23
Q

When is insulin released from the pancreas

A

When plasma glucose is above 5mmol/L

24
Q

What does the binding of insulin to the receptors on liver cell membranes stimulate

A

Glycogenesis, lipogenesis

25
Q

What is the function of glucagon

A

Elevate blood glucose when lower than 3 mmol/L by glycogenolysis in the liver

26
Q

What is the role of cortisol in liver function

A

Released from adrenal glands to stimulate liver gluconeogenesis so more blood glucose for brain

27
Q

What is the role of adrenaline (epinephrine) in liver function

A

Released form adrenal glands to stimulate glycogenolysis and lipolysis

28
Q

What are the 3 main ways glucose enters the blood stream

A

Absorption from small intestine (SGLUT1, GLUT2), glycogenolysis and gluconeogenesis in the liver

29
Q

What is gluconeogenesis

A

Synthesis of glucose from other precursors (amino acids, lactate and glycerol to maintain supply to brain

30
Q

What is lipolysis

A

Beta-oxidation of fatty acid

31
Q

What is de novo lipogenesis

A

Synthesis is endogenous TAG exported from liver into plasma as VLDL lipoproteins (adipose)

32
Q

How does the liver play a role in protein metabolism

A

First organ to receive dietary amino acids via hepatic portal vein and on,g organ capable of eliminating iatrogenic from amino acids (deanimation) to form ammonia and synthesis urea

33
Q

What hormone activates amino acid transporters to increase uptake

A

Glucagon

34
Q

What happens in the liver when we exercise

A

Increased glycogenesis and gluconeogenesis
Increased adipose tissue lipolysis and FFA mobilisation

35
Q

What happens to insulin and glucagon concentrations during exercise

A

Insulin falls so the glucagon to insulin ratio rises

36
Q

What is effect of an increased glucagon/insulin ratio during exercise

A

Adipose tissue releases fatty acid transporters (oxidation of fatty acids for local energy demands)

37
Q

What happens to protein during exercise

A

Increased protein breakdown from skeletal muscle or GI tract, so more AA is circulation as minor direct fuel for muscle (recycled in liver to make glucose)

38
Q

What happens to the associated nitrogen in broken down proteins when AA are recycled in the liver to make glucose during exercise

A

Converted and excreted as urea via kidney

39
Q

Why is liver metabolism not dominant during exercise

A

Reduced blood flow to liver

40
Q

What are the adaptations of the liver to exercise training

A

More effective at fat utilisation for fuel
Reduces liver fat content

41
Q

How can the liver synthesis cholesterol (endogenous cholesterol)

A

From multiple molecules of acetyl-CoA

42
Q

What are bile salts composed of

A

Bile acids, phosphatidylcholine and cholesterol

43
Q

How are bile salts synthesised in the liver

A

Cholesterol is converted into cholic acid and chenodeoxyxholic acid (primary bile acids) in hepatocytes, primary bile acids ar conjugated to glycine or taurine

44
Q

Describe active reuptake of conjugated bile salts

A

In the terminal ileum via sodium dependent bile salt transporter into the portal vein to hepatocytes

45
Q

Describe lipoprotein synthesis

A

Remaining cholestrol synthesised in liver and phospholipids synthesised in the liver is incorporated into lipoproteins

46
Q

How are lipoproteins transported

A

Via blood to peripheral cells

47
Q

What are the functions of phospholipids

A

-lipoprotein synthesis and lipid transport in blood
- membrane structure
- thromboplastin synthesis
- Sphingomyelin synthesis

48
Q

What are the other metabolic functions of the liver

A

Storage of vitamins A, D and B12
Storage of iron
Synthesis of blood clotting proteins
Detoxification
Hormone excretion

NUT1005 (18 decks)

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