3B Physiology of the Liver Flashcards

1
Q

How much glycogen can liver cells store as a percentage of liver weight?

A

8% of liver cell weight 100-120g in adult

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

Where does aa degradation occur almost entirely?

A

Liver

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

What two enzymes are required for deamination in the liver?

A

AST and ALT, which are measure in blood to assess liver function

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

Where is essentially all urea synthesized in the blood?

A

Liver

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

What is a hepatic come or hepatic encephalopathy?

A

In serious liver disease, ammonia often accumulate in the blood

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

Where is urea excreted?

A

Kidneys

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

What is azotemia or uremia?

A

Toxic build up of urea in blood

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

What can cause an elevated BUN?

A

Impaired renal function, increased protein intake or catabolism, GI bleeding, dehydration

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

What is HMG-CoA-reductase?

A

important enzyme in liver hepatocytes required for endogenous cholesterol synthesis

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

What is the only way for the body to eliminate excess cholesterol?

A

Via bile

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

When does ketogenesis occur primarily?

A

Fasting states or poorly controlled type 1 diabetes

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

How does ketogenesis affect the pH of blood?

A

Lower pH (more acidic)

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

Does the liver degrade steroid hormones and T3 and T4?

A

Yes, sir!

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

What is hemachromatosis?

A

To much Fe+2 that begins to deposit in tissues

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

What does gastroferrin do?

A

Makes Fe+2 more soluble and transports it to the small intestine where it is released for absorption

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

What is transferrrin? Apoferritin? Ferritin?

A

Transferrin carries Fe+2 to liver. In liver apoferretin takes Fe+2 to make soluble and the Fe+2 and apoferretin complex is now called Ferritin. Ferritin is the stored form of Fe+2 in the liver

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

The liver stores large quantities of what vitamins?

A

A, B12, and D

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

What is the purpose of metabolizing drugs?

A

Make less active and more water soluble and thus readily excreted in urine and bile

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

Where are Cytochrome P450 enzymes most predominant?

A

Liver, intestines, lungs and other organs

20
Q

What are conjugation reactions designed to do?

A

Make metabolites more polar or hydrophilic, sometimes after they have been created by P450 enzymes

21
Q

What is the most common and most important conjugation reaction?

A

Glucuronidation

22
Q

What is CP450 inhibition?

A

Decreased metabolic activity of CP450 enzymes leading to decreased metabolism of drugs

23
Q

What is CP450 induction?

A

Increased metabolic activity of CP450 enzymes leading to increased metabolism of drugs

24
Q

What stimulates Vitamin D activation in the liver?

25
What are the major types of plasma proteins?
Albumin, globulin, fibrinogen
26
Which plasma proteins are completely formed in the liver? Which one is 50-80% formed in the liver?
Albumin and fibrinogen. Globulin is 50-80% formed in the liver
27
Which blood clotting factors are synthesized in the liver?
All but III, IV and XIII
28
What is the composition of bile?
50% bile salts 40% phospholipids 4% cholesterol 2% bile pigments such as bilirubin
29
Does bile contain water?
Yes and electrolytes, these are secreted by cells lining the bile ducts
30
What are the two primary bile acids? Where are they synthesized?
Cholic acid and chenodeocycholic acid. Synthesized in the hepocytes
31
What converts a portion of the primary bile acids into secondary bile acids? What is the name of the secondary bile acids?
Intestinal bacteria does the conversion. Secondary bile acids are called deoxycholic acid and lithocholic acid
32
The liver conjugates bile acids with what two possible amino acids to form bile salts?
Glycine or taurine
33
What does the conjugation of bile acids w/ glycine or taurine do?
Makes the bile acids amphipathic at duodenal pH
34
What is the most common phospholipid found in bile?
Lecithin
35
Are phospholipids amphipathic?
Yes, sir!
36
The majority of cholesterol breakdown in the body is turned into what in the liver?
Bile
37
How much cholesterol is converted into bile acids and eliminated daily?
500 mg
38
What is the waste product of Hb degradation?
Bilirubin
39
What does conjugation of bilirubin involve? What enzyme is needed?
Attachmen of glucuronic acid to bilirubin. | Glucuronyl transferase
40
Which type of bilirubin is more water soluble?
Conjugated bilirubin
41
What cells secrete ions and water into the bile?
Ithelial cells lining the bile ducts
42
What are other waste products that go into the bile?
Lipolithic drugs and metabolites, antigen-antibody complexes
43
What are the three steps for formation of bile?
Secretion of bile into bile canals (canaliculi). Intrahepatic ducts secrete water bicarb rich fluid. B/w meals about 1/2 of hepatic bile is diverted to the gall bladder, which stores bile and removes salts and water
44
What volume to the first two steps of bile formation produce?
Around 900 mL/day or so called "hepatic bile"
45
What is the result of diverting bile to the gall bladder?
Gall bladder concentrates the key remaining solutes - bile salts, bilirubin, cholesterol and lecithin by 10-20 fold
46
During meals the bile that reachs the duodenum is relatively what?
Dilute hepatic bile and concentrated gall bladder bile
47
What are the two important functions of bile?
Provides sole excretion route for many solutes that are not excreted by the kidneys. Secreted bile salts and lecithin are required for normal lipid digestion and absorption in small intestine