Session 11: Liver and Bile

Question 1

which part of the liver (exo or endo) is responsible for synthesizing and secreting bile via the ductal system? (essential for intestinal digestion)

Answer 1

exocrine

Question 2

which portion of the liver is responsible for synthesizing the secreting numerous plasma proteins into the bloodstream? (exo or endo portion)

Answer 2

endocrine

Question 3

portal triads (aka portal tracts) are found peripherally at the angles of the polygon (lobule of the liver) - why are they so named?

Answer 3

b/c they contain intraheptic branches of the 1. bile ducts 2. hepatic artery and 3. portal vein

Question 4

cells nearest these vessels in the liver receive oxygen and nutrients first

Answer 4

portal acinus

Question 5

within the classic lobule of the liver, sinusoids drain into where?

Answer 5

central vein

Question 6

in terms of relation to the portal tract, which zone considered to be most oxygen and nutrient deficient?

Answer 6

the area most distant from the portal tract - this area also surrounds the terminal hepatic venule

Question 7

what are the two mechanisms by which the liver maintains blood glucose levels?

Answer 7

gluconeogensis and glycogenolysis

Question 8

True or False: endogenous substances including hormones and serum proteins are catabolized by the liver to maintain their production and elimination.

Answer 8

true - also, remember, the liver is the principal site for detoxification of foreign compounds

Question 9

what is the principal excretory product of the liver?

Answer 9

bile

Question 10

what are the 5 components of bile?

Answer 10

bile acids, conjugated bilirubin, phospoholipids, cholesterol and electrolytes.

Question 11

T or F: glossitis is indicative of liver dysfunction.

Answer 11

true - it is common in alcoholic hepatitis

Question 12

bilirubin is the end product of which products breakdown?

Answer 12

it is the product of heme catabolism

Question 13

The majority of bilirubin is derived from what type of RBCs?

Answer 13

senescent erythrocytes. the remaining arises from degradation of heme produced from other sources

Question 14

T or F: circulating bilirubin roams free in the serum

Answer 14

False - it is bound to albumin for transport to the liver

Question 15

what is the % breakdown of blood supply to the liver?

Answer 15

portal vein 75% (brings nutrients from GI tracts) hepatic artery 25% (brings o2 blood)

Question 16

T or F: The liver stops functioning when there is over 50% damage to its mass

Answer 16

False: it can function with damage to 90% of its mass.

Question 17

T or F: a damaged liver can regenerate in 3 weeks

Answer 17

true - it can then be restored to normal function within 4 months

Question 18

T or F: enlarged liver is a direct sign of disease

Answer 18

False; it is instead a sign of an underlying problem such as hepatitis CHF or cancer

Question 19

once bilirubin makes it to the liver it is bound how? (within the hepatocyte)

Answer 19

bound to a group of cytosolic proteins

Question 20

for its excretion, how is bilirubin conjugated?

Answer 20

it is complexed with glucuronic acid

Question 21

T or F: bilirubin is excreted into the bile by an energy-independent carrier mediated process.

Answer 21

FALSE - it is energy dependent

Question 22

what is the feel and size of a liver with cirrhosis?

Answer 22

small and hard

Question 23

if on PE you note that the liver’s soft edge is easily moved - what is the most likely pathology?

Answer 23

hepatitis

Question 24

jaundice occurs when serum bilirubin levels are what?

Answer 24

exceeds 2mg/dl

Question 25

jaundice is associated with what color urine? and what happens to the pt presentation regarding weight and extremities?

Answer 25

dark amber; peripheral edema and weight LOSS (anorexia)

Question 26

bilirubin production mainly takes place where?

Answer 26

production takes place In reticuloendothelial cells, primarily Kupffer’s cells of liver & in reticulo-endothelial cells of spleen, bone marrow, & lymph nodes.

Question 27

which type of bilirubin is water soluble? water insoluble?

Answer 27

water soluble is direct/conjugated. the indirect/unconjugated is insoluble.

Question 28

what happens to water insoluble unconjugated bilirubin? (IOW how does it get to the liver, and what happens once there?)

Answer 28

travels in the bloodstream to the liver where it is converted to water soluble conjugated form and then excreted into the bile (note: only a small amount remains unconjugated in the plasma circulation)