Liver structure and function

Question 1

which lobe is bigger?

Answer 1

Right

Question 2

what are the names given to the 2 minor lobes?

Answer 2

caudate

quadrate

Question 3

what joins the common hepatic duct with the gallbladder?

Answer 3

cystic duct

Question 4

what is the bare area of the liver?

Answer 4

small area on diaphragmatic surface surrounded by coronary ligament that is not covered by peritoneum

coronary ligament (not like ligaments we’ve come across before - this type is more an attachment) connects the liver to the under side of the diaphragm

Question 5

What is the function of networks of septa that go deep into the body of the liver?

Answer 5

supports the liver

Question 6

what do you find at each corner of the hexagonal shaped lobule?

Answer 6

portal triad ( contains hepatic portal vein, hepatic artery, hepatic duct)

Question 7

which quadrant does the liver lie in

Answer 7

upper right quadrant of the abdomen

Question 8

what enters/exits the liver via the Porta on its inferior surface (4)

Answer 8

blood vessels - hepatic portal vein and artery

lymphatic vessels

ducts - R/L hepatic duct

nerves (hepatic nerve plexus)

Question 9

What do septa divide the liver into?

Answer 9

hexagonal lobules

Question 10

What lies in the centre of each lobule?

Answer 10

central veins

which drain to hepatic veins that then drain to the inferior vena cava

Question 11

what radiate out from central veins?

Answer 11

hepatic cords

Question 12

what are hepatic cords composed of?

Answer 12

hepatocytes - functional cells of liver

Question 13

Where are bile canaliculus located within the lobule? what is put into these channels

Answer 13

between cells within each cord

hepatocytes put their products (bile etc) into these channels

Question 14

What is the space between hepatic cords called? and what is found within this space?

Answer 14

hepatic sinusoids - a discontinuous capillary network that allows for mixing of blood

blood channels

Question 15

What do central veins do?

Answer 15

They receive the blood mixed in the liver sinusoids and return it to circulation via the hepatic veins.

Question 16

What is the primary role of hepatocytes?

Answer 16

to make bile which they then secrete into canaliculi

Question 17

Other functions of hepatocytes other than bile synthesis?

Answer 17

nutrient storage
(glycogen, fat, vits (B12,A,D,E,K), Cu, Fe)

nutrient interconversion - make and convert nutrients into any type of chemical really

detoxification of things like alcohol etc

Question 18

Liver’s role with Glucose

Answer 18

The liver converts glucose to glycogen

It stores glycogen up to it’s maximum amount and after that a person has to tap into different energy stores

Question 19

What role does the liver have within the alimentary system

Answer 19

production & secretion of bile

Question 20

6 components of bile

Answer 20

Bile acids
Lecithin
cholesterol
bile pigments - bilirubin
toxic metals
bicarbonate - neutralises acid chyme

Question 21

What is common with all of these:-
Bile acids
Lecithin
cholesterol

Answer 21

they are synthesised in the liver

they solubilise fat - act as emulsifying agents

Question 22

Bilirubin: yellow and brown pigment

Answer 22

if bilirubin is extracted from blood by hepatocytes and secreted into bile - yellow bile

bilirubin is modified by bacterial enzymes - brown faeces

Question 23

How come urine is yellow?

Answer 23

reabsorbed bilirubin is excreted in urine

Question 24

What colour is bilirubin pigment naturally

Answer 24

bright yellow

Question 25

What do bile acids bind with to increase their solubility just before secretion?

Answer 25

glycine or taurine

this turns them into bile salts

Question 26

what is a bile salt?

Answer 26

a conjugated bile acid

Question 27

how are secreted bile salts recycled?

Answer 27

via the enterohepatic circulation

Question 28

3 layers of gallbladder wall

Answer 28

mucosa - expansion
muscularis - contraction
serosa

Question 29

Secretin is released in response to what? and what does it achieve

Answer 29

acid in the duodenum

neutralisation

Question 30

how does secretin work?

Answer 30

it is released in response to acid in the duodenum

it decreases gastric acid secretion

decreases gastric emptying (slows time for food to move from stomach to small intestine)

increases duodenal HCO3 secretion

Increases pancreatic HCO3

increases bile duct HCO3 secretion

neutralised acid

Question 31

Cholecystokinin (CCK) is released in response to what? and what does it achieve?

Answer 31

fat/amino acids in duodenum

digestion

Question 32

how does CCK work?

Answer 32

decreases gastric emptying

increases pancreatic enzyme secretion - aid digestion

Gallbladder contraction

relaxation of sphincter of Oddi (surrounds end portion of the common bile duct and pancreatic duct. If relaxed - allows bile and pancreatic juice to flow into intestine)