sem1: Liver

Question 1

what do hepatocytes(60%) do

Answer 1

perform metabolic functions- removal of toxic substances(alcohol)

Question 2

what do kupffer cells(30%) do

Answer 2

tissue macrophage - et RBC, bacteria, viruses

Question 3

what is the functional unit of the liver

Answer 3

hepatic lobule

Question 4

what is the hepatic lobule made of

Answer 4

hepatocytes and a central hepatic venule

Question 5

at each corner of hepatic lobule what does the triad consist of

Answer 5

hepatic artery (75%)
portal vein (25%)
bile duct

Question 6

the blood travels from the corner to the central vein by small channels called what

Answer 6

sinusoids

Question 7

what are the sinusoids lined by

Answer 7

hepatocytes

Question 8

what secretes bile

Answer 8

hepatocytes

Question 9

where does the hepatocytes secrete bile into

Answer 9

channels- canaliculi

Question 10

biliary system ducts (6)

Answer 10

canaliculi 
ductule 
left/right hepatic duct 
common hepatic duct 
cystic duct 
common bile duct

Question 11

where are kupffer cells found

Answer 11

in sinusoids

Question 12

what do kupffer cells do

Answer 12

remove gut bacteria/ antigens

Question 13

what is the first step of bile seceretion

Answer 13

by hepatocytes: 
bile acids
bilirubin 
cholesterol 
phospholipids

Question 14

what is the second step of bile secretion stimulated by

Answer 14

hormone secretin

Question 15

what is the second step of bile seceretion

Answer 15

epithelial cells secreting water and electrolytes such as Na+ and bicarbonates

Question 16

normally cholesterol is soluble in

Answer 16

bile

Question 17

how are gall stones formed

Answer 17

due to precipitation of gall stones in bile

Question 18

what are two types of gall stones

Answer 18

pigment (80%)

cholesterol (20%)

Question 19

what are the 3 factors in increased risk of gall stone formation

Answer 19

• high fat diet
• women- estrogen
• inflammation of epithelial cells

Question 20

what are the two things that cholestrol gets broken down into (acids)

Answer 20

cholic acids

chenodeoxycholic acid

Question 21

what are these two acids conjugated with

Answer 21

amino acids to make more soluable

Question 22

what is the conjugated form released into

Answer 22

cannaliculi

Question 23

how much of bile is reabsorbed at the terminal ileum

Answer 23

95%

Question 24

what vein returns the blood to hepatocytes from ileum

Answer 24

portal vein

Question 25

what happens to the 5% of bile

Answer 25

lost in faeces

Question 26

how many times a day is the same pool of bile circulated

Answer 26

6-8

Question 27

what other purpose does bile serve other than fat emulsification

Answer 27

removal of waste: bilirubin and cholesterol

Question 28

what is bilirubin the product of

Answer 28

breakdown of haemoglobin

Question 29

what is haem converted to

Answer 29

free bilirubin

Question 30

what is free bilirubin bound to

Answer 30

albumin

Question 31

what is the bilirubin bound to albumin conjugated with

Answer 31

amino acid (glucoronic acid)

Question 32

what is the conjugated form of free bilirubin with amino acid secreted into and then metabolised by

Answer 32

bile | intestinal bacteria

Question 33

what is the major metabolite of bilirubin in urine

Answer 33

urobilin | urobilinogen

Question 34

what is the major metabolite of bilirubin in faeces

Answer 34

stercobilin

Question 35

what is jaundice

Answer 35

either free or conjugated bilirubin in ECF

Question 36

what is the sclera

Answer 36

white part of the eye

Question 37

where does yellow appear in jaundice patients

Answer 37

skin sclera mucosal membrane

Question 38

what is the normal concentration of bilirubin in the plasma

Answer 38

0.5mg/dL

Question 39

what is the abnormal concentration of bilirubin in the plasma

Answer 39

1.5mg/dL

Question 40

when do you get green discolouration

Answer 40

mutation of biliverdin reductase gene

Question 41

what does biliverdin reductase gene convert

Answer 41

biliverdin to bilirubin

Question 42

what causes the green colour jaudice

Answer 42

biliverdin

Question 43

3 types of jaundice

Answer 43

pre hepatic hepatic post hepatic

Question 44

what is pre hepatic jaundice

Answer 44

too much haemolysis | neonates

Question 45

what is hepatic

Answer 45

problems with hepatocytes due to cirrhosis, hepatitis, drugs inc in serum bilirubin

Question 46

what is post hepatic

Answer 46

passage of conjugated bilirubin into duodenum blocked, leak out into circulation and urine

Question 47

what happens to excess proteins

Answer 47

- keto group converted to glucose or lipids - urea cycle - synthesis of plasmaproteins

Question 48

what can ammonia do

Answer 48

depress cerebral blood flow and cerebral oxygen consumption | -interferes with GABA and dopamine

Question 49

what does interference with GABA and dopamine lead to

Answer 49

hepatic encephalopathy

Question 50

what enzyme catalyses redox reactions in phase 1 of drug metabolism

Answer 50

cytochrome P450

Question 51

where does phase 1 of drug metabolism take place

Answer 51

smooth ER

Question 52

what happens in phase 2 of drug metabolism

Answer 52

- conjugation with glucuronyl to make water soluble | - removal using ATPase pumps

Question 53

what three pathways for paracetamol metabolism

Answer 53

1. glucoronidation 2. sulfation 3. N-hydroxylation and dehydration

Question 54

with the N-hydroxylation and dehydration pathway for paracetamol metabolism what is the intermediate formed

Answer 54

NAPQI- toxic

Question 55

what detoxifies NAPQI

Answer 55

glutathione conjugation

Question 56

in paracetamol overdose what is the treatment

Answer 56

N-acetyl cysteine which is precursor of glutathione

Question 57

what does reactions with NAPQI and nucleic acids/ proteins lead to

Answer 57

liver necrosis and kidney damage

Question 58

what is the first step of alcohol metabolism

Answer 58

ethanol to acetaldehyde catalysed by alcohol dehydrogenase

Question 59

what is reduced in the first step of alcohol metabolism

Answer 59

NAD+ to NADH

Question 60

what does NADH and H+ react with

Answer 60

pyruvate

Question 61

this depleted supply of pyruvate will inhibit what and lead to what

Answer 61

gluconeogenesis | hypoglycemia

Question 62

what will the build of lactic acid lead to

Answer 62

acidosis

Question 63

what are the three stages of liver damage due to drinking

Answer 63

fatty liver alcohol hepatitis cirrhosis

Question 64

what does vit B12 deficiency lead to

Answer 64

pernicious anaemia

Question 65

what enzyme indicates a obstruction to bile flow

Answer 65

ALP- alkaline phosphatase | GGT

Question 66

what does albumin in blood test tell us

Answer 66

decreased in chronic liver disease

Question 67

what does bilirubin in blood say

Answer 67

jaundice

Question 68

what does alanine amino transferase(ALT) suggest

Answer 68

alcohol induced damage- leak out of hepatocytes