Liver

Question 1

functions of the liver

Answer 1

carb metabolism, fat metabolism, source of cholesterol, source of AA and proteins, storage, detoxification, and immune function

Question 2

what are some differences in healthy vs. injured cells of liver

Answer 2

in injured, there are activated HSC, loss of fenestrate, activated kupffer cells, deposition of scars of ECM

Question 3

liver composed of

Answer 3

lobules

Question 4

what provides the hepatic blood

Answer 4

75% - portal vein

25% - hepatic artery

Question 5

what provides the hepatic blood

Answer 5

75% - portal vein

25% - hepatic artery

Question 6

sinusoids drain into

Answer 6

central veins which unite to form hepatic veins

Question 7

functional unit of liver

Answer 7

acinus

Question 8

zones of the liver

Answer 8

zone I: cells closest to the arteriole and have the highest delivery of oxygen

zone II: transition zone

zone III: cells furthest away from the arteriole and oxygen and nutrient supply is the least

Question 9

zones of the liver

Answer 9

zone I: cells closest to the arteriole and have the highest delivery of oxygen

zone II: transition zone

zone III: cells furthest away from the arteriole and oxygen and nutrient supply is the least

Question 10

zone most susceptible to drug toxicity

Answer 10

zone III

Question 11

zone that will preferentially undertake oxidative metabolism, ureagenesis, gluconeogenesis, and bile production

Answer 11

zone I

Question 12

zone that will undertake glycolysis, ketogenesis, detoxification, xenobiotic metabolism

Answer 12

zone III

Question 13

largest fraction of total fluid secretion that makes up bile consists of

Answer 13

isotonic fluid with electrolyte concentration favoring plasma

Question 14

epithelial cells lining the biliary tree secretes what

Answer 14

HCO3 in response to high levels of secretin (like pancreas)

Question 15

hepatic bile is compromised of secretions from where

Answer 15

hepatocytes and biliary tree

Question 16

hepatic bile is compromised of secretions from where

Answer 16

hepatocytes and biliary tree

Question 17

what type of fluids come from the hepatocytes and biliary tree

Answer 17

hepatocytes - canalicular bile made up of organic molecules, NaCl/water

biliary tree - ductular bile made up of NaHCO3/water

Question 18

amount of bile made per day

Answer 18

500mL

Question 19

how does bile facilitate fat digestion

Answer 19

emulsification and solubilization through formation of mixed micelles

Question 20

is bile alkaline or acidic

Answer 20

alkaline to help to neutralize the gastric acid

Question 21

what does mixed micelle do to facilitate fat digestion

Answer 21

enhances efficiency of lipase action and delivery of fat digestion products to absorptive enterocytes

Question 22

difference between kidney and bile in excretion of compounds

Answer 22

kidney helps to excrete smaller water soluble compounds while bile helps to excrete larger hydrophobic molecules

Question 23

can fat still be absorbed without bile salts

Answer 23

yes but it is not as efficient

Question 24

70% of bile is made up of

Answer 24

bile acids

Question 25

70% of bile is made up of

Answer 25

bile acids

Question 26

20% of bile solids are

Answer 26

phospholipids aka lecthins

Question 27

cholesterol is what percentage of bile solids

Answer 27

4%

Question 28

what are the amphipathic component of bile

Answer 28

phospholipids and bile acids (aka bile salts) which together form mixed micelles

Question 29

what is hydrophobic component of bile

Answer 29

cholesterol and must be in center of micelle to be dissolved

Question 30

% of primary and secondary bile acids in bile

Answer 30

primary - cholic (50%) and chenodeoxycholic acid (30%)

secondary - deoxycholic (15%) and lithocholic acid (5%)

Question 31

% of primary and secondary bile acids in bile

Answer 31

primary - cholic (50%) and chenodeoxycholic acid (30%)

secondary - deoxycholic (15%) and lithocholic acid (5%)

Question 32

what makes the secondary bile acids less soluble less than primary bile acids

Answer 32

the loss of polar OH- groups

Question 33

solubilize hydrophobic molecules and promote their diffusion to the absorptive membrane of the enterocytes

Answer 33

micelles

Question 34

since the bile pool is lower than needed to assimilate the lipid content of a typical meal, what is the compensation

Answer 34

bile acids are recycled and total bile pool is secreted twice during a meal and about 6-8 times a day through enterohepatic circulation of bile acids

Question 35

major reabsorption of bile acid is where

Answer 35

distal ileum via Na+/bile acid cotransporter

Question 36

bile acids that are deconjugated are absorbed where

Answer 36

jejunum by simple diffusion due to higher lipid permeability

Question 37

rate limiting step in secretion of bile acids

Answer 37

transport across the canalicular membrane via facilitated diffusion