the liver

Question 1

the largest organ in the body

Answer 1

the liver

Question 2

can the liver regenrate if damaged

Answer 2

yes

Question 3

how many lobes does the liver have
name them

Answer 3

4
left
right
caudate
quadrate

Question 4

the two sources of blood supply to the liver

Answer 4

hepatic artery
hepatic portal vein

blood from the hepatic artery is oxygen rich and blood from the hepatic portal vein is nutrient rich. hepatic artery can carry nutrients(in smaller proportions), but the hepatic portal vein cannot carry oxygen

Question 5

liver lobules

Answer 5

hexagonal structures consisting of hepatocytes

Question 6

what is found at each of the six ends(corners) of liver lobules

Answer 6

a portal triad

Question 7

liver sinusoids

Answer 7

specialised blood vessels lined with unique endothelial cells and are responsible for filtering blood from the hepatic portal vein and hepatic artery, allowing hepatocytes (liver cells) to interact with blood components.

found in the liver ofc

Question 8

kupffer cells

Answer 8

specialized macrophages found in the liver(sinusoids)

Question 9

liver fibrosis

functions of stellate cells

Answer 9

storage of vitamin A
They can transform into myofibroblasts, contributing to the deposition of extracellular matrix proteins like collagen

Question 10

functions of basolateral membrane

Answer 10

involved in the exchange of substances between the hepatocytes and the interstitial fluid or blood.

has microvilli

Question 11

apical membrane function

Answer 11

responsible for interactions with the external environment

Question 12

Bile ducts leave the liver via the common…………….

Answer 12

hepatic duct

Question 13

function of bile salts

Answer 13

emulsify lipids (fats)

Question 14

what do bile salts flow through to the bile duct

Answer 14

bile canaliculi

Question 15

what stimulates the gall bladder

Answer 15

cholecystokinin (CCK) and secretin

Question 16

gall bladder function

Answer 16

Stores bile that is not immediately needed fordigestion

It’s important to note that the gallbladder is not essential for survival, and individuals can live relatively normally after gallbladder removal (cholecystectomy). However, without a gallbladder, the release of bile into the small intestine becomes more continuous, and some individuals may experience changes in digestion and fat absorption.

Question 17

bile acids can conjugate with amino acids, especially taurine and glycine. what is the reason for this ?

Answer 17

Increases polarity of molecules

Question 18

bile acids are derived from ?

Answer 18

cholesterol

they are not the same as bile, they are rather the primary ingredient in bile that carry out fat emulsification

Question 19

name some of the components of bile

Answer 19

bile salts, bile pigments, cholesterol, neutral fats, phospholipids and electrolytes

Question 20

name the sinusoidal transporters

Answer 20

NTCP (sodium taurocholate transporter). - bile acidtransporter (symport with sodium)

OATP (organic anion transporterprotein)

OCT (organic cation)

MRP4 – transport drug metabolites back into the blood

Pept1 (Peptide Transporter 1)

Question 21

name some bilary transporters

proteins responsible for the movement of substances, including bile acids, bilirubin, and other organic molecules, across the canalicular membrane of hepatocytes into the bile canaliculi

Answer 21

Biliuribin transported to bile by MRP-2

ABCG 5/8 – transport cholesterol

MDR3 – PC

BSEP – Bile Salts

MDR1 (P Glycoprotein)–Drug and metabolites

BCRP (breast cancer resistant protein) - steroid derivatives

Question 22

space of disse function

Answer 22

acts as a site for the exchange of substances between the sinusoidal blood and hepatocytes. It is involved in nutrient exchange, metabolic processes, and interactions between different cell types within the liver

Question 23

function of P-glycoprotein

Answer 23

Removing drugs absorbed in the intestines back into the gut lumen. Maintaining the integrity of the blood brain barrier.
Removing drugs from the kidneys and liver into the urine and bile respectively.

Question 24

bilirubin

elevated levels of bilirubin can cause?

Answer 24

yellowish-brown pigment that is formed during the breakdown of red blood cells. It is a by product of haemoglobin, the oxygen-carrying component of red blood cells. When red blood cells reach the end of their life cycle, they are broken down in the spleen, and haemoglobin is released. The haem portion of haemoglobin is then converted into biliverdin, which is subsequently converted into bilirubin.

jaundice

Question 25

bilirubin is excreted from the liver in ?

it is excreted from the body as?

Answer 25

bile

faeces

Question 26

enterohepatic circulation

Answer 26

physiological process involving the circulation of substances, such as bile acids, between the liver and the small intestine. It plays a crucial role in the reabsorption and recycling of these substances.

Question 27

glycogen phosphorylase function

Answer 27

Glycogen phosphorylase catalyzes the cleavage of glucose units from the glycogen polymer, releasing glucose-1-phosphate.
This process is important in providing a quick and readily available source of glucose when the demand for energy is high, such as during exercise or between meals.

Question 28

the active form of glycogen phosphorylase

the inactive form

Answer 28

Phosphorylase a (Phosphorylated)

Phosphorylase b( not phosphorylated )

Question 29

phosphorylase b is activated to phosphorylase a by which enzyme

phosphorylase A deactivated to phosphorylase b by?

Answer 29

Phosphorylase Kinase

Phosphorylase Phosphatase

Question 30

if glycogen is not synthesised, then what happens to glycogen synthase and why

Answer 30

it should be inactivated or switched off

otherwise a “futile cycle” will ensue