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Flashcards in Hepatobility Deck (51):
1

What is the functional unit of the liver?

-Lobule

2

What is a lobule structure?

-Hexagonal shape, triad of bile duct/hepatic portal vein/hepatic artery at each corner.
-Lobule is all hepatocytes which drain into one central vein.
-Make up ~80% of liver volume

3

What is the function of microvilli on each side of liver endothelium?

-Increase surface area

4

What are Kuppfer cells?

-Macrophages in sinusoid which consume RBCs, bacteria

5

What is the function of endothelial cells in the liver?

-Line the sinusoids, make it very porous so large particles and proteins and shit can move through.

6

What are the stellate cells in the liver?

-Fat storing cells for vitamin A and fat soluble vitamins
-Can turn into myofibroblasts in the case of liver damage. May play a role in cirrhosis.

7

What are cannaliculi in the liver and what flows through them?

-Channels between cell membranes of adjacent hepatocytes which carry bile

8

Describe preferential enzyme expression:

-Function of hepatocytes is determined by their relative proximity to central veins.
-Zone 1 is furthest from central vein, thus most highly oxygenated
-Zone 3 is closest to central vein and least oxygenated

9

What do Zone 1 hepatocytes carry out?

-amino acid metabolism, gluconeogenesis, ureageneis, cholesterol synthesis, and bile formation

10

What do zone 3 hepatocytes carry out?

-Glycolysis
-Glycogen synthesis
-Lipogenesis
-Ketogenesis
-Drug metabolism

11

How much of the liver oxygen supply comes from the portal vein? Hepatic artery?

-60-70%
-30-40%

12

What are the functions of the liver?

-Nutrient metabolism
-Biotransformation
-Filtration
-Hormone conversion and activation

13

What is phase 1 of biotransformation?

-Oxidation-reduction, cytochrome P450 enzyme

14

What is phase 2 of biotransformation?

-Conjugation to make metabolites more polar/water soluble for excretion

15

What carries out filtration at the liver?

-Kuppfer cells

16

How are hormones converted and activated at the liver?

-Vitamin D is hydrolyzed here
-T4 is deiodinized into T3

17

What is the main nutrient metabolized at the liver? How?

-Carbohydrates
-Converts CHO to triglycerides for storage as fat outside of liver

18

What are the three forms of cholesterol?

-Dietary (as chylomicrons)
-en novo
-LDL

19

What are the two ways that cholesterol is exported from the liver?

-As bile acids

-As VLDL to be sent to other cells to make cellular components or steroid hormones

20

What proteins are produced at the liver?

-ALBUMIN
-Fibrinogen
-Clotting factors
-Globulins
-Angiotensinogen
-Apolipoproteins

21

What is the main function of albumin?

-Maintains plasma oncotic pressure.
-Binds and transports substances in blood.

22

How are proteins metabolized?

-Transamination
-Oxidative deamination

23

What is transamination?

-Transfer of an amino group to a ketoacid to participate in gluconeogenesis, lipid synthesis

24

What is bilirubin? What is it's function?

-Pigment that occurs when RBCs break down.
-Gives bile it's color

25

How is bilirubin formed?

-RBC breaks down, biliverdin is formed
-converts to free bilirubin, binds to albumin in blood
-converts to conjugated bilirubin in blood, now conjugated.

26

What is jaundice and how is it caused?

Yellowing of the skin. Due to excessive biulirubinas a result of excess bilirubin lysis, decreased hepatic blood flow, obstruction of bile ducts, reduced conjugation of bilirubin.

27

What is the function of bile?

-Allows bilirubin and cholesterol to be excreted

28

Wha do bile acids and bile salts promote?

Digestion and absorption of lipids.

29

What are micelles? What do they do?

Formed by bile salts and bile acids. They emulsify lipids so they can be absorbed

30

Why is gallbladder bile more concentrated than hepatic bile?

-Water is taken out;

31

Describe enterohepatic circulation

-More bile is excreted than is generated, most of this is reabsorbed.

32

What are ALT and AST?

-alanine aminotransferase
-aspartate aminotransferase
-tells you about liver damage

33

What does serum albumin tell us?

-About synthetic capability of l;over
-If the liver can make proteins

34

What does alkaline phosphatase tell us?

-about liver excretory function.

35

What is the function of the gallbladder?

Secrete concentrated bile into duodenum

36

What is cholestasis? Causes?

-blockage of gallbladder
-Stones, cirrhosis, neoplasm outside of liver
-Common symptom is itching

37

What is cholestisis? Acute vs Chronic? Signs

-Inflammation of gallbladder
-Associated with partial or complete obstruction of cystic or common duct.
-Acute signs=vomiting, right upper quadrant pain
-Chronic: pain, intolerance to fatty foods

38

What is cholelithiasis? Cause?

-Gall stones
-Too much cholesterol, not enough bile salts

39

What is hepatitis?

-Viral infection of liver cells
-Most cellular damage comes from self immune response

40

Describe Hep A

-RNA virus
-No symptoms in kids, jaundice in adults
-Fecal-oral transmission

41

Hep B

-DNA, blood borne and bodily fluids
-There is a vaccine
-Can cause cirrhosis and necrosis
-plays role in Hep D

42

Hep C

-RNA virus, blood borne
-Most commonly vaccinated for
-Can be acute or chronic
-May cause cancer

43

Hep D

-Requires Hep B infection
-No treatment, DNA virus, blood borne.
-Can be acute or chronic

44

Hep E

-RNA virus, fecal oral transmission
-Similar to Hep A
-Impacts pregnant women

45

Hep G

Basically Hep C

46

Describe chronic hepatitis

-Result of B, C, or D
-3-6 months
-Most common cause of liver transplant in adults

47

What is pancreatitis?

-Inflammation of pancreas due to alcohol or trauma
-Enzymes from pancreas released to surrounding tissues
-Chronic due to alcohol abuse or cystic fibrosis

48

How is pancreatitis treated?

-NPO
-NGT
-Total Parenteral Nutrition

49

Describe liver cancer

-Highly linked to Hep B and Hep C
-Low survival rate
-Palleative care
-Associated with cirrhosis

50

Describe pancreatic/gallbladder cancer

-Prancreatic is 4th most common cause of cancer death
-common in blacks

Gallbladder cancer: 1% 5 year survival rate, diagnosed at surgery because symptoms involve gallstones

51

What makes up alcoholic liver disease?

-Cirrhosis (stellate cells)
-Fatty liver
-Alcoholic hepatitis