Hepatic System

Question 1

Describe the structure of Glisson’s capsule

Answer 1

Connective tissue covered by mesothelium layer.

- rich in nerve endings.

Question 2

The liver has __ lobes, __ major and __ minor.

Answer 2

4 2 2

Question 3

What is a liver lobule

Answer 3

Functional unit of the liver.

Question 4

Describe the composition of the lobule

Answer 4

Central terminal hepatic venule
Interconnecting plates of hepatocytes
Peripherally arranged portal triad

Question 5

State the 3 hepatocyte zones which differ by levels of ____

Answer 5

centrilobular, periportal, mid zone

oxidation

Question 6

Describe the structure of a hepatic lobule

Answer 6

hexagonal
central vein
portal triad
plates of hepatocytes w sinusoids.

Question 7

what are the 3 vessels of the portal triad

Answer 7

hepatic portal vein
hepatic artery
bile duct

Question 8

Hepatic portal vein:

• state direction of blood flow.
• state function

Answer 8

blood to liver from digestive tract (75%)

filters toxins from digestive tract

Question 9

Hepatic artery

- state direction of blood flow

Answer 9

oxygenated blood from aorta to liver (25%)

Question 10

Which cells do sinusoids contain?

Answer 10

Kupffer cell lining

Hepatic stellate cells

Question 11

What are the 2 main structures of the hepatobiliary system?

Answer 11

Bile canaculi & bile ducts

Question 12

Describe the flow of blood & bile in the liver acinus (lobule)

Answer 12

OPPOSITE DIRECTION OF FLOW:

Blood flow towards central vein, bile away.

Question 13

State functions of the liver

Answer 13

xenobiotic detoxification & metabolism
erythrocyte decomposition & bilirubin excretion
bile production
cholesterol synthesis & lipogenesis
carbohydrate metabolism
protein synthesis
hormone production
storage

Question 14

Which proteins are synthesised by the liver?

Answer 14

Albumin

Coagulation of fibrinogen, prothrombin, factors (V, VII, IX-XI), antithrombin

Question 15

Which hormones are synthesised by the liver?

Answer 15

Thrombopoietin

Angiotensin

Question 16

State the function of thrombopoietin

Answer 16

regulates platelet production by bone marrow

Question 17

State the function of angiotensin

Answer 17

raises BP following renin activation

Question 18

Which substances are stored by the liver?

Answer 18

Glycogen
Fat soluble vits A D E K
Water soluble vits B12
Iron, Copper

Question 19

Glycogenolysis

Answer 19

stored glycogen -> glucose

Question 20

Gluconeogenesis

State the 2 cycles involved

Answer 20

Exhausted glycogen store: non-carbohydrates -> glucose.

Cori & Alanine cycle

Question 21

Glycogenesis

Answer 21

XS glucose -> glycogen storage

Question 22

Describe the Cori Cycle

Answer 22

Anaerobic conditions.

Flow of lactate & glucose between active muscles & liver.

Question 23

Describe the Alanine Cycle

Answer 23

Protein degradation -> glucose.

Question 24

State the hormones which effect glucose regulation

Answer 24

insulin, glucagon, adrenalin, cortisol

Question 25

Describe lipid metabolism in the liver.

Answer 25

- Glucose converted to fatty acids via acetyl-CoA - VLDL formed. - cholesterol synthesis

Question 26

Cholesterol uses:

Answer 26

Synthesis of bile acids, cell membranes, hormones

Question 27

XS cholesterol is converted to ___ ___ OR _____ with bile

Answer 27

bile acids | excreted

Question 28

Bile is linked to ____ ____ to form bile salts

Answer 28

amino acids (Glycine or Taurine)

Question 29

State a characteristic of bile acids

Answer 29

AMPIPATHIC (polar & apolar side)

Question 30

Bile is produced by ____ (Cells) & passes into ___ _____ which carry bile back to ____ ____

Answer 30

hepatocytes, bile canaliculi, portal triad

Question 31

Describe erythrocyte degradation to form bilirubin.

Answer 31

Erythrocyte phagocytosis -> haemoglobin released Globin metabolised Amino acids recycled Iron bound to transferrin is returned to liver Haem converted to bilirubin & bound to albumin.

Question 32

In the liver: uptake of bilirubin by _____. Bilirubin dissociates from ____ & enters ____. Bilirubin conjugated with __ _____ ____ via ___-______ ______. Conjugated bilirubin transported into ___ _____ and ____. Intestinal bacteria degrade bilirubin to _______. 80% oxidised to ____ and excreted via ____. 20% enters ______ ______ and excreted via _____.

Answer 32

hepatocytes albumin, hepatocytes 2 glucuronic acids, UDP-glucuronyl transferase bile canalculi, bile urobilinogen stercobilin, faeces extrahepatic circulation, urine

Question 33

Describe the first pass effect.

Answer 33

Absorbed [drug] is reduced by liver before reaching the systemic circulation. REDUCES DRUG BIOAVAILIBILITY

Question 34

Describe the 2 phases of drug metabolism

Answer 34

PI: add/unmask func groups to convert compound to more POLAR (HYDROPHILIC) metabolite PII: CONJUGATION to increase AQUEOUS SOLUBILITY.

Question 35

State some phase I metabolism reactions.

Answer 35

OXIDATION (CYP450s), reduction, hydrolytic cleavage, alkylation

Question 36

State some phase II metabolism reactions.

Answer 36

CONJUGATION by GLUCURONIDATION, sulfation, acetylation.

Question 37

Hepatitis

Answer 37

Liver inflammation

Question 38

Cirrhosis

Answer 38

Fibrous tissue in liver forms & replaces dead cells

Question 39

Haemochromatosis

Answer 39

Excessive iron accumulation & liver damage

Question 40

Wilson's disease

Answer 40

Copper retention (hereditary)

Question 41

Biliary cirrhosis

Answer 41

disease of bile ducts

Question 42

Gilbert's syndrome

Answer 42

bilirubin metabolism disorder (genetic)

Question 43

Jaudice

Answer 43

Yellow skin, nail beds & sclera. causes: hyperbilirubinemia -> deposition of bilirubin. IMPORTANCE: marker of hepatic disease.

Question 44

State 3 liver function assessment biomarkers (and their enzymes).

Answer 44

TRANSAMINASES (ALT, AST) CHOLESTATIC enzymes (ALP, GGT) BILIRUBIN