Liver, gall bladder, and pancreas histology

Question 1

What comprises the portal triad?

Answer 1

A hepatic artery, portal vein, and bile duct.

Question 2

What is the lymph vessel is a portal triad derived from?

Answer 2

The space of Disse.

Question 3

What cell type makes up most hepatocytes?

Answer 3

Bi-nucleate cells that are polyploid (4N).

Question 4

What are the three surfaces of a hepatocyte?

Answer 4

Baso-lateral, sinusoidal, and cannicular. (Also have the space of Disse for lymphatics)

Question 5

What is the flow of bile in a portal triad?

Answer 5

Bile flows counter-current (bile flows towards the portal triad while the blood flows towards the central vein).

Question 6

What are the three types of liver lobules?

Answer 6

Classic lobule, portal lobule, and acinar lobule.

Question 7

What is the function of classic lobules?

Answer 7

Endocrine function of the liver (fibrinogen, albumin, glucose produced and secreted elsewhere).

Question 8

What is the function of portal lobules?

Answer 8

Exocrine function of the liver (secretes bile and other products into bile duct).

Question 9

What is the function of acinar lobules?

Answer 9

Reflects gradient of metabolic activity in the liver (comprised of three zones).

Question 10

What is the shape of a classic lobule?

Answer 10

They are polygonal in shape.

Question 11

What is the organization of a classic lobule?

Answer 11

Portal canals at the periphery and a central vein in the center.

Question 12

What is the shape of a portal lobule?

Answer 12

They are triangular in shape.

Question 13

What is the organization of a portal lobule?

Answer 13

Portal canal (portal triad) at the center and central veins in the peripheral apices (drain bile into the bile cannaliculi in the triad).

Question 14

What is the organization of a acinar lobule?

Answer 14

Portal triads and central veins at the periphery.

Question 15

What are the zones of acinar lobules based on?

Answer 15

Whether a hepatocyte is peripheral to the central vein or peripheral to the portal triad (i.e. how close a cell is to the blood supply).

Question 16

What are the three zones of an acinar lobule?

Answer 16

Zone 1 (periportal), Zone 2 (mid-region), and Zone 3 (centro-lobular). Zone 1 is closest to the blood supply and Zone 3 is farthest.

Question 17

Which zone of an acinar lobule is the last to die?

Answer 17

Zone 1. Hepatocytes here receive the most nutrients and blood,

Question 18

Which zone of an acinar lobule is the first to die?

Answer 18

Zone 3. Is the farthest away from nutrients/blood.

Question 19

What cytological differences are present between the zones of an acinar lobule?

Answer 19

Metabolic differences (metabolic gradient in the liver). Includes carbohydrate metabolism, drug metabolism, ect).

Question 20

In a healthy liver what is the capacity for hepatocyte regeneration?

Answer 20

Cells in all three zones will regenerate.

Question 21

In a liver with zonal damage (pathology) what is the capacity for hepatocyte regeneration?

Answer 21

There is selective regeneration of damaged zones as opposed to regeneration in all zones.

Question 22

What kind of abnormal regeneration occurs in hepatic cirrhosis?

Answer 22

CT elements do not cooperate, resulting in altered hepatic structure and compromised parenchymal function.

Question 23

Where are receptor-ligand complexes of endocrine hormones targeted to the liver (insulin, glucagon,ect) degraded?

Answer 23

In the lysosomes of hepatocytes. An absence of lysosomes leads to a variety of disorders.

Question 24

Where are the apoproteins for lipoprotein complexes synthesized?

Answer 24

In the rER of hepatocytes.

Question 25

What is the function of the smooth ER in hepatocytes?

Answer 25

Synthesis of cholesterol/phospholipids, esterification of FFA, convert T3 to T4, drug metabolism, synthesis of cholic acid, and Ca2+ storage.

Question 26

What do hepatic peroxisomes metabolize?

Answer 26

Purine catabolism (produces uric acid), alcohols, ect.

Question 27

What kinds of receptors do Kupffer cell posses?

Answer 27

Fc and complement receptors to phagocytose immune complexes, bacteria, and non-immune particulates.

Question 28

What is another function of kupffer cells?

Answer 28

They bind and degrade hemoglobin to bilirubin (shared function with the spleen).

Question 29

What are Ito cells?

Answer 29

Hepatic lipocytes.

Question 30

What do Ito cells store?

Answer 30

They can act as reserves of vitamin A (lipid soluble).

Question 31

What is another function of Ito cells?

Answer 31

They can take up lipophilic/membranolytic molecules that lysosomes can’t process/are damaged by (ex. detergents,ect).

Question 32

What are the intrahepatic biliary channels?

Answer 32

Bile canaliculus to terminal ductules to interlobular bile ducts.

Question 33

What is gallbladder mucosa similar to?

Answer 33

It is similar to GI mucosa except that it doesn’t posses a submucosa (lamina propria followed by the muscularr layer).

Question 34

What are the four major cell types of the pancreas?

Answer 34

Alpha, beta, delta, and PP cells.

Question 35

What do alpha cells produce?

Answer 35

Glucagon

Question 36

What do beta cells produce?

Answer 36

Insulin and amylin

Question 37

What do delta cells produce?

Answer 37

Somatostopin

Question 38

What do PP cells produce?

Answer 38

Pancreatic polypeptide

Question 39

What are the three minor pancreatic cell types?

Answer 39

Delta-1, EC cells, and epsilon cells.