Liver Flashcards
Gross anatomy
The liver can be split into………. lobes (……… and ……..), which are separated by the ………………….. …………………
The liver receives a ……………… blood supply, which reflects its important ………………, ……………… and ……………… functions. The main perfusing vessels are the ……………… ……………… (blood from heart) and ……………… ……………… ……………… (blood from the gut).
Each lobe can be further separated into discrete segments, with their own anatomical borders, but more crucially, with an ……………… blood supply and ………………drainage. Why is this important?
Each subsection drains into its own ………………, with those subsequently draining into the …………….. , ……………… and ……………… hepatic ……………… before joining the ……………. ………………
Gross anatomy
The liver can be split into two lobes (right and left), which are separated by the falciform ligament.
The liver receives a dual blood supply, which reflects its important metabolic, secretary and immunological functions. The main perfusing vessels are the hepatic artery (blood from heart) and hepatic portal vein (blood from the gut).
Each lobe can be further separated into discrete segments, with their own anatomical borders, but more crucially, with an independent blood supply and bile drainage. Because of this, it is quite possible to have severe damage in one part of the liver without affecting other parts. The subsections are numbered from I to VIII (although IV is usually split into upper (a) and lower (b) subsegments).
Each subsection drains into its own vein, with those subsequently draining into the left, middle and right hepatic veins before joining the vena cava
What are the names of the lobes of the liver
4 lobes – left, right, caudate, quadrate
What ligament seperates the left and right lobe and attaches to the diaphragm?
Falciform ligament
What is the couinaud classification of the liver?
The Couinaud classification of liver anatomy divides the liver into eight functionally independent segments. Each segment has its own vascular inflow, outflow and biliary drainage. In the centre of each segment there is a branch of the portal vein, hepatic artery and bile duct.
What two vessels make up the livers dual supply?
Blood from the liver drains into the ……………. ……………. …………. via the ……………… vein
What is the purpose of blood delivered to the liver by;
- Hepatic portal vein?
- Hepatic artery?
- Hepatic artery? Delivers oxygenated blood rich in nutrients to support the liver
- Hepatic portal vein? To breakdown any toxic substances that may of been digested
What shape is a classical lobule?
What 4 parts can a lobule be split into?
What are at the corner of each lobule?
The classical lobule is hexaganol and divided in concentric centrilobular, midzonal and periportal parts
The portal lobule centred on a portal triad
Acinus: elliptical or diamond shaped divided into 3 zones
What are at the corner of each lobule? Branch of hepatic portal vein, brach of bile duct and brach of hepatic artery (portal traid)
The hepatic lobule
How do the lobules fit together in the liver?
Define Hepatic Acinus?
What does the Hepatic Acinus consist of and what do they share?
What zones can the acinus be split inot and describe them?
Portal tracts are composed of…?
Portal tracts are composed of:
- an arteriole
- a branch of the portal vein
- a bile duct
What is a sinusoid>
a small irregularly shaped blood vessel found in certain organs, especially the liver.
Name the 5 cell types of the liver?
Flattened, dense cell nuclei that appear to be in the sinusoids are ………….. cells or ………….. ………… cells
…………….. are large cells with pale and rounded nuclei.
Flattened, dense cell nuclei that appear to be in the sinusoids are Kupffer cells or hepatic stellate cells
Hepatocytes are large cells with pale and rounded nuclei.
Hepatocytes within which zone are most susceptible to;
- Ischaemia?
- Viral hepatitis?
Hepatocytes within which zone are most susceptible to;
- Ischaemia? zone 3
- Viral hepatitis? zone 1
Look at where the portal triad is- the hepatic artery
- Bile produced by ………………..
- Flows along ………………..to bile duct
- Bile produced by hepatocytes
- Flows along canaliculus to bile duct
What are the functions and features of the 5 cell types of the liver?
Where are kuppfer cells found and what are they attached to and what is its shape and its function?
Make seperate cards for each one when you are free?
•Hepatic stellate cells
- Vitamin A storage
- Activation = ECM production (fibrogenesis)
•
•Sinusoidal endothelial cells
•Fenestrated – allows lipid and other large molecule movement to and from hepatocytes
•Kupffer cells
- Phagocytosis (inc. RBC breakdown)
- Secretion of cytokines that promote HSC Activation - proliferation, contraction and fibrogenesis
What is the livers role in the metabolism of carbohydrates?
Important to control blood glucose (endocrine course)
After a meal, blood glucose and is taken up by tissues
Stored as glycogen mainly in muscle and liver
Breakdown liver glycogen maintains blood glucose concentration between meals (muscle cannot release glucose back into blood)
24h fast will exhaust liver glycogen (80g) - Then what?
Draw a diagram showing the liver’s role in protein metabolism and write its role as well?
What process is used to produce non-essentail amino acids?
The livers job to produce non essentail amino acids ( ones the body can make themselves)
Essentail amino acids- have to get from diet
Transamination-Different keto-acids can be converted to multiple amino acids depending on the transaminase enzyme (vital for production of non-essential amino acids.
Glucose-alanine cycle - Deamination
Problem:
Muscle can potentially utilise amino acids to produce glucose for energy;
BUT
- To convert pyruvate to glucose requires energy
- To remove nitrogen as urea requires energy
How does the body overcome this issue?
Solution – transfer problem to the liver (glucose-alanine cycle)
What is the ccori cycle?
The Cori cycle (also known as the Lactic acid cycle), named after its discoverers, Carl Ferdinand Cori and Gerty Cori, refers to the metabolic pathway in which lactate produced by anaerobic glycolysis in the muscles moves to the liver and is converted to glucose, which then returns to the muscles and is metabolized
Draw a diagram showing the role of liver metabolism of tryglycerides?
Look at hassan’snotes on the google drive
Acetyl-CoA can be used as an energy source for the liver
What happens to the glycerol in the diagram below?
What two lipoproteins does the liver produce?
What are their roles?
The liver produces two lipoproteins. VLDL and HDL.
VLDL has a high triacylglycerol component and it’s major role is to deliver fatty acids to body tissues (lipoprotein lipase cleaves the fatty acids from triglycerides). Those fatty acids can be used as an energy source of can be stored in the adipose tissue as tri-glycerides.
HDL are often referred to as ‘empty’ lipoproteins – they have high protein content but low fat content. Their role is to mop up excess cholesterol in the circulation and return to the liver – hence why they are often referred to as ‘good’ fat.
Once VLDL have delivered fatty acids to tissues, they are converted to LDL which are very high in cholesterol. The LDL deliver cholesterol to tissues which then use the cholesterol to make hormones and to maintain cell membrane integrity. Any excess cholesterol is returned to the liver and excreted in bile.
What are the fat soluble vitames?
Which one of them have a small reserve of?
What else is stored in th eliver which isn’t obvious?
Storage of fat soluble vitamins (A,D,E,K). Stores sufficient 6-12 month except Vit K where store is small. Vit K essential blood clotting
Storage of iron as ferritin. Available for erythropoeisis
Liver detoxification- two phase process
State it?
P450 enzymes
Phase 1 – more hyrdrophilic
Phase 2 – attach water soluble side chain to make
less reactive
