1. Liver Microanatomy
Alice and Drew

2. Hepatocytes Main functional cell of the liver
Joined together in cords towards a central vein
Cords separated by sinusoids
Granular appearance - lots of mitochondria
Other organelles - RER, SER, large golgi body, lysosomes and peroxisomes. Glycogen deposits and lipid droplets can be visible
Hepatocytes are the main functional cell of the liver. They are joined together in cords, which converge on a central vein. The individual cords are seperated by sinosoids, which carry blood.
The granular appearance of the hepatocytes is due to lots of mitochondria, which is related to their high energy requirement. They have many different organelles, so the RER (which is to do with protein synthesis), the SER (which is to do with the enzymes involved in the inactivation of drugs and toxins) and the golgi body. The golgi is continuous with RER and SER vesicles and tubules. There are also visible glycogen deposits and lipid droplets.
Different functional domains - sinusoidal, canalicular, intercellular

3. Hepatocyte Ultrastructure
N - Nucleus
GI - Glycogen deposits
M - Mitochondria
BC - Biliary canaliculi
This is an electronmicrograph of the hepatocyte.
Could ask them to label it?

4. Sinusoids
Fenestrated, made up of endothelial cells, Kupffer cells and Ito cells
Kupffer - tissue macrophages. Partially responsible for bilirubin production
Ito - Store fat
Combination of arterial (30%) and venous (70%) blood
Sit on reticulin (Collagen III)
Separated from hepatocytes by space of Disse
Sinusoids are fenestrated, made up of endothelial cells, kupffer cells and ito cells. Kupffer cells are the resident tissue macrophages of the liver. They display phagocytic activity against blood borne materials entering the liver. The ito cells store fat and are also known as Stellate cells. The sinusoids are a combination of arterial and venous blood. They are supported by a reteculin mesh (which is collagen III). The sinusoids are separated from hepatocytes by the space of Disse - where transfer of materials takes place

5. Biliary Canaliculi Where bile is secreted to from hepatocytes
Drain in opposite direction to blood flow
The bile canaliculi are the channels where bile is secreted from the hepatocytes. The bile canaliculi drain towards the bile ductile, in the opossitee direction to the blood flow (which flows towards the central vein). In the picture above the bile ductiles are labelled green.

6. Portal Triad Portal vein. Carries deoxygenated nutrient-rich blood
Hepatic arteriole. Small and muscular
Bile ductule
The portal triad form at the ‘corners’ of the lobule and it the ‘entrance’ into the lobule. The potal bein carries deoxygenated nutrient rich blood which comes from the GI tract. The hepatic arteriole is small and muscular and carries oxygenated blood from the hepatic arteries. Both the arterial and venous blood then runs toward the central vein through the sinusoids. The bile ductule is also present.

7. Lobule Structure
This is the functional unit of the liver. It is roughly hexagonal in shape. Each lobule has a central portal vein, and the portal triads are at each corner of the hexagon

8. Zones
This is an alternate picture of the organisation of the liver. The Acinus - double triangle, cluster of cells
Zone 1 - Closest to the portal triad = Highest O2 concentration = contains the enzymes for oxidative reactions = make and store glycogen and produce and secrete proteins
Zone 2 - mixture of functions of Zone 1 and 2
Zone 3 - Lower oxygen - contain many esterases - conjugating and detox reactions (There is another session on detox)

9. General Histology Advice
Anki!!!
Only use the pics that are on minerva
Learning them = easy exam marks
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