liver microanatomy part 1&2 W4

Question 1

general anatomical summary of the liver

Answer 1

large lobulated exocrine and blood processing bland with vessels and ducts entering and leaving at the porta

Question 2

what is the liver enclosed by

Answer 2

thin collagen tissue capsule, mostly covered by mesothelium

Question 3

what provides gross support to the liver

Answer 3

collagen tissue of the branching vascular system

Question 4

vessels entering the liver? function?

Answer 4

portal vein: bringing food-rich blood from the gut

hepatic artery: bringing arterial blood

Question 5

vessels leaving the liver? function?

Answer 5

hepatic veins: taking away processed blood into the vena cava
lymphatics: take away lymph
hepatic ducts: removing bile to the gallbladder and gut

Question 6

what are parenchymal cells supported by

Answer 6

fine reticular fibres

Question 7

liver blood supply %’s?

Answer 7

hepatic artery: 25%
portal vein: 75%

Question 8

liver lobule features

Answer 8

cells arranged in perforated plates one cell wide. in-between are sinusoidal blood channels, lined by epithelial cells
blood vessels mark out hepatic lobules

Question 9

where is the portal triad and what is it composed of

Answer 9

in corners of lobule.
branch of portal vein
branch of hepatic artery (thicker muscular wall)
bile duct

Question 10

portal tract?

Answer 10

collagen area separating lobules

Question 11

central vein features?

Answer 11

very thin wall, lies in centre of lobule, with sinusoids converging towards and opening into it

Question 12

sublobular/intercalated vein features?

Answer 12

thicker wall, lies alone at periphery of lobule

Question 13

features of hepatic blood flow?

Answer 13

from periphery (portal vein, hepatic artery) to central vein, through the sinusoids between cell plates

central veins -> sublobular veins -> collecting veins -> hepatic veins

Question 14

bile flow?

Answer 14

intralobular bile flow is from the lobules centre towards the peripheral bile ducts, and runs, within any one cell plate, between the liver cells in bile canaliculi

Question 15

what are liver sinusoids?

Answer 15

low pressure vascular channels that receive blood from terminal branches of the hepatic artery and portal vein at the periphery of lobules and deliver it into central veins

Question 16

what are liver sinusoids lined with? what do these hold?

Answer 16

fenestrated endothelial cells, hold phagocytic Kupffer cells (large, stellate, pale oval nucleus)

Question 17

features of fenestrated lining cells?

Answer 17

not tightly attached, rest on microvilli of underlying hepatic cells without a basal lamina intervening

Question 18

what is found between the fenestrated lining cells and hepatocytes?

Answer 18

space of Disse

Question 19

stellate cells?

Answer 19

lie outside the endothelial cells. store vitamin A. respond to variety of insults by making collagen and causing cirrhosis (fibrosis)

Question 20

sinusoidal wall provides for what?

Answer 20

blood cleansing
haemopoiesis in embryo
bringing plasma into contact with hepatic cell for metabolic functions of storage, transformations, syntheses, regulation of plasma concentrations, detoxifications, bile production, acute phase proteins production

Question 21

main functional cells of the liver?

Answer 21

hepatocytes

Question 22

faces of hepatocytes

Answer 22

sinusoidal face
lateral faces (neighbouring hepatocytes)

Question 23

where is bile formed?

Answer 23

small portion of modified lateral faces form bile canaliculi

Question 24

presence of microvilli on hepatocytes?

Answer 24

sinusoidal face - abundant
bile canaliculi - sparse