L7 - liver anatomy and function

Question 1

features of liver

Answer 1

• largest solid organ
• in the right upper quadrat
• composed of 2 lobes separated by falciform ligament

Question 2

what factors can keads to variation in liver anatomy

Answer 2

• genetic
• internal like fibrosis, cirhhosis which are harmful
• external - injury, tights belts, accessory lobe or clefts (not harmful and not functional )

Question 3

pathway of bile from the liver all the way to intestine

Answer 3

• bile made in liver goes through the hepatic duct and join with common ducts to be collected in the gallbladder
• hepatopancreatic sphincter relaxes to allow the bile go into the intestine to emulsify the fats upon detecting peptides and carbohydrates

Question 4

what are the blood vessels in the liver

Answer 4

• portal vein - carries venous blood and substances from the gut
• hepatic artery - carries arterial blood
• blood mixes with sinusoids and drains via hepatic vein

Question 5

what is liver stroma and what it’s composed of

Answer 5

• capsule like covering the liver containing connective tissue
• composed of ECM that covers reticular network and portal tract
• has glycoproteins and allows for bidirectional communication between cells through intergrins

Question 6

how many zones does a lobule or an acinus have

Answer 6

3 zones - zone 1,2,3

Question 7

how does fibrosis and cirrhosis occur

Answer 7

CT builds up in between hepatocytes and the cells moves away from each other

• then scar tissue is formed
• too much of CT destroys the liver cells during cirrhosis

Question 8

in what direction does the blood flow to in the liver cell

Answer 8

from the portal tract on the edge of the cell to the centre where it’s drained into the central vein

Question 9

features of hepatocytes

Answer 9

• polarised polyhedral epithelial cells
• low mitotic index
• main functional cells inthe liver
• very versatile

Question 10

features of biliary epithelium

Answer 10

• very dense membrane composing of cuboidal or columnar epithelial or bilial cells
• the cells has TJs to stop bile from going in to the membrane
• secretes stuff to modify the bile

Question 11

features of endothelium

Answer 11

• squamous epithelial cells
• protects parenchyma from RBCs, bacteria and viruses
• selective uptake of solutes
• transport of immunitic cells
• regulates coagulation and leukocyte
• clears debris

Question 12

features of kuffer cells

Answer 12

• hepatic macrophages
• does phagocytosis and removes toxins
• produces immune responses

Question 13

features of stellate cells

Answer 13

• stores fats
• can become fibroblasts in response to immune activation and contribute to fibrosis
• star shaped

Question 14

functions of liver

Answer 14

-digestion, immune response, bioproduction, metabolism and coagulation

Question 15

what biomolecules are metabolised in the liver

Answer 15

• carbohydrates,
• fats.
• proteins

Question 16

why is cholesterol important

Answer 16

• involved in membrane permeability and fluidity

- involved in production of bile acids, steroid hormones and Vit D

Question 17

phases in detoxification

Answer 17

phase 1 - foreign compounds are metabolised by oxidation by P450 enzymes
phase 2- then the compounds are conjugated with water soluble products to be excreted into bile or urine

Question 18

what proteins are made in the liver

Answer 18

• albumin - useful for maintaining osmotic fluid balance and transports materials into the blood stream
• fibronectin and factors for coagulation casade
• plasminogen
• hepcidin

Question 19

do ppl die due to actal cirrhosis

Answer 19

no

• die due to consequences of the condition
• like renal failure, portal hypertension, ascites

Question 20

what is portal hypertension

Answer 20

increases BP due to vascular resistance caused by the liver damage

Question 21

other causes of liver damage

Answer 21

• viral hepatisis
• alcohol
• obesity