liver tissue architecture

Question 1

functional unit of liver: shape?

Answer 1

hexagonal (6) lobules
surrounding a central vein

Question 2

what are on the edge of each hexagonal lobule surrounding a central vein?

Answer 2

portal triad

Question 3

portal triad constists of what?

Answer 3

portal vein, hepatic artery, bile duct

also lymphatics

Question 4

portal vein, hepatic artery, bile duct

what is this?

Answer 4

portal triad

Question 5

how many portal triads surrounding a central vein?

Answer 5

6 (hexagonal)

Question 6

apical surface of hepatocytes face what?

Answer 6

bile canaliculi

Question 7

basolateral surface of hepatocytes face what?

Answer 7

sinusoids

Question 8

what are kupffer cells?

Answer 8

specialized macrophages in sinusoids of liver

Question 9

what are specialized macrophages in sinusoids of liver called?

Answer 9

Kupffer

Question 10

what is a liver sinusoid?

Answer 10

vessels that receive blood from terminal branches from
- hepatic artery
- portal vein

located the periphery of lobules

deliver blood into central veins

Question 11

kupffer cells: role?

Answer 11

clear bacteria and damaged/senescent RBCs

Question 12

which cells clear bacteria and damaged RBCs in the liver?

Answer 12

Kupffer cells

Question 13

what are hepatic stellate cells also called?

Answer 13

Ito cells

Question 14

what are Ito cells?

Answer 14

hepatic stellate cells

store Vitamin A

Question 15

Hepatic stellate (Ito) cells: role when quiescent?

Answer 15

vitamin A storage

Question 16

Hepatic stellate (Ito) cells: role when active?

Answer 16

make ECM

Question 17

what are the 2 roles of Ito cells?

Answer 17

vitamin A storage, ECM production

Question 18

which cells are responsible for hepatic fibrosis?

Answer 18

Ito cells

Question 19

where are stellate hepatic cells (ito cells) located?

Answer 19

in the space of Disse

Question 20

which Vit A storing cell type does the space of Disse contain?

Answer 20

Ito cells

Question 21

what is the space of Disse?

Answer 21

space between hepatocyte and sinusoid

Question 22

where are Kupffer cells located?

Answer 22

in the sinusoids of the liver

Question 23

what are the 3 zones of the hepatic hexagon?

Answer 23

Zone I: periportal (near portal triad)
Zone II: intermediate
Zone III: pericentral (centrilobular) zone

Question 24

Which hepatic zone is first affected by viral hepatitis?

Answer 24

Zone I: periportal zone

Question 25

which hepatic zone is most oxygenated?

Answer 25

Zone I: periportal zone

Question 26

which hepatic zone is most resistant to circulatory compromise?

Answer 26

Zone I: periportal zone

Question 27

what is zone I in the liver hexagon called?

Answer 27

periportal zone

Question 28

which zone is affected in yellow fever?

Answer 28

zone II: intermediate zone

Question 29

what is yellow fever?

Answer 29

infection of yellow fever virus, spread via mosquitoes. symptoms include fever, muscle pain, headache, loss of appetite, nausea or vomiting. normally symptoms disappear in 3-4 days sometimes second, more toxic phase within 24 hrs from recovering from initial symptoms

Question 30

what is zone II called?

Answer 30

intermediate zone

Question 31

what characterizes the second, toxic phase of yellow fever?

Answer 31

High fever returns. liver and the kidneys affected. jaundice, dark urine, abdominal pain with vomiting, bleeding. 50% dies

Question 32

what is zone III called?

Answer 32

pericentral (centrilobular) zone

Question 33

which zone is first affected by ischemia?

Answer 33

zone III

Question 34

zone III has a high concentration of which enzyme?

Answer 34

cytochrome P-450

Question 35

cytochrome P-450, high concentration in which zone?

Answer 35

zone III pericentral

Question 36

which zone is most sensitive to metabolic toxins?

Answer 36

zone III

Question 37

what are examples of metabolic toxins to which zone III is sensitive?

Answer 37

ethanol, CCl4, halothane, rifampin, acetominophen

Question 38

what is rifampin?

Answer 38

antibiotics to treat TB

Question 39

what is halothane?

Answer 39

inhalation anesthetic

Question 40

what is CCl4?

Answer 40

very hepatotoxic chemical compound (used in cleaning supplies, no longer permitted)

Question 41

where is the site (zone) of alcoholic hepatitis?

Answer 41

zone III, pericentral