Liv4

Question 1

surface anatomy

Answer 1

mainly upper R quadrant

protected by rib cage

Question 2

gross anatomy

Answer 2

4 lobes 
R biggest
L/
caudate lobe in middle 
quadrate lobe below it 
falciform ligament - attach to diaphragm 
common bile duct - lead to gall bladder

Question 3

blood in liver

Answer 3

hepatic portal vein and artery to liver

hepatic vein - away

Question 4

functional anatomy

Answer 4

cauinaud classification
8 functionally independent sections - own blood supply and venous drainage
central - HPV artery and bile duct
periphery - hepatic vein

Question 5

blood supply

Answer 5

25% CO
dual - 20% hepatic artery, oxygenated and 80% HPV - deoxygenated from gut
HPV and artery mixed = overall poor oxygenation
hepatic vein drains into vena cava

Question 6

purpose of hepatic artery

Answer 6

oxygen and nutrients

Question 7

purpose of HPV

Answer 7

take breakdown products of gut

liver has a high metabolic rate

Question 8

morphological anatomy

Answer 8

lobules
HPV and artery combine in sinusoid
lined by epithelia - substances can diffuce across into hepatocytes
sinusoid pass through lobule to central vein to vena cava
portal triad/tract - bile duct, HPV and artery
centrilobular hepatocyte - centre of lobe
periprotal hepatocyte

Question 9

portal triad

Answer 9

around edge of lobule

Question 10

acinus

Answer 10

functional
less well defined
unit of hepatocytes divided into zones dependant on proximity to arterial blood supply
zone 1-3
1 near portal triad - risk of viral infection
3 near central vein - risk of ischemia

Question 11

hepatocytes

Answer 11

80% of the mass
large cell
pale and round nuclei
radiate from the central vein

Question 12

which cells appear to be in sinusoids

Answer 12

kuppfer/stellate
flattened
dense nuclei

Question 13

histology of non-parenchymal cells

Answer 13

endothelial cells - nuclei red and flat
Kupffer cells - cytoplasm blue, nuclei red
hepatocytes - nuclei red and round

Question 14

stellate cells

Answer 14

vitamin A storage
activation = ECM formation - fibrinogenesis
respond to proinflammatory environment
important in cirrhosis - fibrotic lesion

Question 15

sinusoidal endothelial cells

Answer 15

fenestrated - allow lipid and large molecule movement to and from hepatocytes

Question 16

Kupffer cells

Answer 16

phagocytosis
including RBC breakdown
secretion of cytokines that promote stellate cell activation - fibrinogenesis

Question 17

four functions of liver

Answer 17

control synth and met of protein
maintenance of blood sugar
lipid met
Metabolism and excretion of bilirubin and bile acids.

Question 18

control synth and met of protein

Answer 18

albumin
transferrin - transport and carrier proteins
coagulation factors and complement
degradation of aa -> urea

Question 19

Maintenance of blood sugar

Answer 19

release glucose
breakdown glycogen
synth glucose from aa or glycerol

Question 20

Lipid metabolism.

Answer 20

manufacture most cholesterol -> make bile salts

synth lipoproteins and triglycerides

Question 21

Metabolism and excretion of bilirubin and bile acid

Answer 21

bile acids are from cholesterol

Question 22

metabolism of carbohydrates

Answer 22

store of glycogen only available for 24hrs
glucose enter muscle = TCA cycle/lactate production
lactate converted to pyruvate in liver via lactate dehydrogenase
pyruvate is converted to glycose by gluconeogenesis
requires 6ATP

Question 23

synthesis of protein

Answer 23

aa from diet or muscle break down
enter liver
liver makes secreted proteins eg plasma proteins, clotting factors and lipoproteins

Question 24

transamination

Answer 24

transfer essential to non-essential AA
keto acids are a go between
alanine transaminase

Question 25

different transamination reactions

Answer 25

depends on the transaminase
a keto-glutarate –> glutamate, proline, arginine
pyrivate –> alanine, valine, leucine
oxaloacetate –> aspartate, methionine, lysine

Question 26

why is deamination needed

Answer 26

muscle can use AA to produce glucose
but energy required to convert pyruvate to glucose and remove nitrogen
so job is given to liver

Question 27

deamination

Answer 27

glucose-alanine cycle
pyruvate and glutamate form alanine in muscle alanine converted to glutamate and pyruvate in the liver
pyruvate converted back to glucose with addition of 6ATP - TCA
glutamate broken into urea by addition of 4ATP - utilised to make glucose

Question 28

triglyceride metabolism

Answer 28

adipose tissue: triglyceride into FA
liver: FA vie B oxidation to acetyl CoA to TCA
OR liver generate ketones: 2x acetyl CoA -> acetoacetate - leave the liver as tissue energy source

Question 29

lipoprotein synthesis

Answer 29

glucose enters converted to glycerol and pyruvate
pyruvate –> acetyl CoA
acetyl CoA –> FA and cholesterol
glycerol –> triacylglycerol
triacylglycerol+ apoproteins and phospholipids + cholesterol –> lipoproteins

Question 30

action of lipoproteins

Answer 30

VLDL - transport FA to tissues
VLDL –> LDL
LDL converts chol to tissues
HDL - pick up excess chol, have few FA

Question 31

storage

Answer 31

fat sol vit - A, E, D, K
A D E store sufficient for 6 month
store iron as ferratin - available for erythropoiesis

Question 32

detoxification

Answer 32

phase 1 - P450 make more hydrophilic so easier to secrete in urine
phase 2 - attach water soluble side chain to make less reactive so less likely to leave blood until reaches kidney