Lab 3: Histology Flashcards
(73 cards)
Histologically, how can you tell the difference between a vein and an artery?
Vein: thinner walled as there is no thick layer of smooth muscle
In what direction is the flow of fluid in the lobule for the following vessels:
A) Hepatic artery
B) portal vein
C) bile duct
A and B: towards the central vein
C: from the central vein
Describe the route for bile?
The hepatocytes secrete bile acids, bile pigments and cholesterol into canaliculi, which lie between adjacent cells

Would be at the center of the lobule if you wanted an anatomical view of it?
Center would be the central vein
Would be at the center of the lobule if you wanted an physiological view of it?
Center would be the portal tract
Describe the hepatic acinus zone theory?
The hepatic acinus can be described in terms of metabolic “zones”.
These three zones are based upon oxygen supply
Runs between two portal triads.
Zone 1: encircles the portal tracts where the oxygenated blood from hepatic arteries enters.
Zone 3: is located around central veins, where oxygenation is poor.
Zone 2 is located in between.

Which zone in the lobule does the paracetamol and alcohol have most effect?
Most effect in zone 3 because the metabolism of these drugs require oxygen
Describe the zone 1 hepatocytes?
Receive blood rich in oxygen and have a high level of metabolic activity.
The oxidative functions of the liver tend to be performed mainly by hepatocytes in zone 1

Describe zone 3 hepatocytes?
Function
Receive blood low in oxygen
Metabolic processes that can operate at lower oxygen tensions occurring mainly in zone 3
Important for glycolysis and cytochrome P450 drug detoxification

Which zone of the lobule is bile production and secretion mainly occuring in?
Mainly zone 1
Which zone is closest to the portal triad?
Zone 1 (high perfused)

Which zone is closest to the central vein?
Zone 3

Which zone of the lobule does glycolysis and cytochrome P450 drug detoxification occur in?
Mainly zone 3
Which zone is the site of most drug and alcohol detoxification?
zone 3
Which zone of the lobule does paracetamol overdose and alcohol effect?
Zone 3

Which zone of the lobule does phosphorous poisoning effect?
Zone 1
What is the recommended number of units of alcohol a week?
14 units per week spaced out
For both men and women
What is one unit of alcohol?
10ml of pure alcohol
Therefore approx 1 shot of spirit (as a shot of around 25ml is 40%)
Describe the pathogenesis of cirrhosis?
When liver parenchymal cells are destroyed, they are replaced with fibrous tissue that eventually contracts around the blood vessel.
This greatly impedes the flow of portal blood through the liver.
What are some common causes of cirrhosis of the liver?
- Chronic alcoholism
- Nonalcoholic steatohepatitis i.e. liver inflammation and damage caused by a buildup of fat in the liver
- Nonalcoholic fatty liver disease i.e. a term for a range of conditions caused by a build-up of fat in the liver.
- Ingestion of poisons e.g. carbon tetrachloride
- Viral disease e.g. hepatitis B
Name these parts of the liver?

- Coronary ligament
- Fissure for ligamentum venosum
- Porta hepatis
- Gallbladder
- Quadrate lobe
- Bare area
- Round ligament (ligamentum teres) of liver (obliterated umbilical vein) forming free border of falciform ligament
- Falciform ligament

Describe the fissure for ligamentum venosum
Fibrous remnant of the ductus venosus of the fetal circulation
Bile is ___ produced
Continously produced
Bile is only needed during which times?
During or after meals but it is continously produced.
Stored in the gallbladder when not required

















