13 Liver I

Question 1

How much cardiac output is devoted to the liver?

Answer 1

25%

Question 2

Does the portal vein or hepatic artery supply more blood to the liver?

Answer 2

Portal

[portal= 60-80% and hepatic= 20-40%]

Question 3

How does pancreatic hormones get to the liver?

Answer 3

pancreatic venous drainage is into portal system

Question 4

T-F– portal blood may contain gut derived antigens, bacteria products, and other cells?

Answer 4

True

Question 5

What does the lobule of the liver comprise?

Answer 5

central vein with plates(cords) of hepatocytes arrayed radially from it [hexagonal]

Question 6

What is located at the corners of the hexagonal lobules?

Answer 6

portal triad [hepatic artery, portal vein, small bile duct]

Question 7

Are the portal triad vessels inflow or outflow?

Answer 7

inflow

Question 8

What is the functional unit of the alternative view of the liver with the central view around the portal triads?

Answer 8

liver acinus [more sense physiologically due to focusing on where blood enters the parenchyma]

Question 9

What is larger to draw in 2 dimensions- the acinus or the lobule?

Answer 9

acinus

Question 10

What are the hepatic cords lined by?

Answer 10

sinusoids- sinusoidal endothelial cells [special capillary]

Question 11

are liver sinusoidal epithelial cells fenestrated? adhere closely to one another? have a complete basement membrane?

Answer 11

yes fenestrated, no adhere closely, no complete basement

Question 12

Where does the exchange of substances take place in the liver?

Answer 12

across the space of disse

Question 13

characteristics of sinusoidal epithelial cells in the liver offer what 2 important things?

Answer 13

1. porous–>nutrient exchange

2. maintain low pressure

Question 14

What occurs during chronic liver disease?What does this eventually lead to?

Answer 14

1. scar tissue in space of disse
   decreased caliber of the sinusoids
2. portal hypertension

Question 15

What are the macrophages of the liver? where are they located?

Answer 15

kupffer- reside in lumen of the sinusoids

Question 16

What glucose metabolism processes take place in the liver?

Answer 16

glycogenesis, glycogenolysis, gluconeogenesis

Question 17

What can happen in an acetaminophen overdose?

Answer 17

acute liver injury leading to hypoglycemia

Question 18

Does the liver have a major role in lipid metabolism? What roles?

Answer 18

yes [synthesizes cholesterol and lipoprotein, trafficking of lipoprotein particles, everything to do with triglycerides]

Question 19

What is the primary organs for amino acid transformations?

Answer 19

liver

Question 20

What amino acid altering enzymes are only used by hepatocytes and are therefore used as an indicator for liver damage?

Answer 20

alanine aminotransferase (ALT)
aspartate aminotransferase (AST)

Question 21

What can occur in cirrhosis and contribute to hepatic encephalopathy?

Answer 21

Impaired detox of ammonia

Question 22

What is the replacement of liver tissue with fibrosis?

Answer 22

cirrhosis

Question 23

What regulates oncotic pressure and carries many diff. ligands?

Answer 23

albumin- produced in liver

Question 24

What is made in liver and is a strong protease inhibitor?

Answer 24

alpha1- antitrypsin

Question 25

What is made in liver and precursor for angiotensin II?

Answer 25

angiotensinogen

Question 26

What is made in liver and is an inhibitor of intrinsic coagulation system?

Answer 26

antithrombin III

Question 27

what is made in liver and an assembly of lipoprotein particles?

Answer 27

apo-B

Question 28

What is made in the liver and is a copper transporter?

Answer 28

ceruloplasmin

Question 29

What coagulation factors are made in the liver?

Answer 29

II, VII, IX, X

Question 30

Is fibrinogen made in the kidney?

Answer 30

NO---liver

Question 31

What is made in the liver and binds and transports cell-free hemoglobin?

Answer 31

haptoglobin

Question 32

What is made in liver and is a carrier for thyroid hormone in the bloodstream?

Answer 32

thyroxine binding globulin

Question 33

What is made in the liver for iron transport?

Answer 33

transferrin

Question 34

What is the principal organ for drug metabolism?

Answer 34

liver

Question 35

In the liver is polar compounds converted to more lipophilic substrates during drug metabolism?

Answer 35

No- lipophilic ---> more polar [allows excretion in the bile]

Question 36

- What type of reaction is mainly catalyzed by cytochrome P450 in the ER and involved in ox-red reactions where the oxygen group is inserted into the compound?- - Is the product more or less reactive?

Answer 36

Phase I-often produces a more reactive intermediate

Question 37

Are the substrate specificities of the cytochrome P450 enzymes narrow and singular?

Answer 37

No- broad and overlapping

Question 38

What type of reaction usually involve conjugation of the compound to a group that increases water solubility?

Answer 38

Phase II

Question 39

If too much acetaminophen is taken, what shift takes place?

Answer 39

shift to cytochrome p450 pathway--->reactive intermediate--->glutathione can't keep detoxing and damage ensues

Question 40

What is the effective treatment for acetaminophen overdose?

Answer 40

N-acetylcysteine

Question 41

Can alcohol ingestion induce p450 pathway and allow acetaminophen toxicity at lower levels?

Answer 41

yes

Question 42

What makes up bile?

Answer 42

water, electrolytes, bile acids, cholesterols, phospholipids and bilirubin

Question 43

Is bile concentrated during fasting?

Answer 43

yes

Question 44

What cells make bile?

Answer 44

hepatocytes

Question 45

What does bile do?

Answer 45

emulsifies fat

Question 46

What results from many types of liver injury and can cause malabsorption and deficiencies in fat soluble vitamins?

Answer 46

cholestasis

Question 47

T-F---bile is important for the elimination of cholesterol?

Answer 47

yes- conversion of cholesterol to bile acids

Question 48

What creates gall stones?

Answer 48

precipitation of cholesterol out of bile

Question 49

What drug can be used to decrease enterohepatic recirculation of bile ?

Answer 49

cholestyramine

Question 50

bilirubin is a breakdown of what?

Answer 50

heme porphyrin----> metabolized by bacteria [calcium bilirubinate gallstones can occur in patients with accelerated turnover of RBCs]