The Liver Flashcards
Where is the liver located?
Right hand side, behind the diaphragm
(Size and structure varies between species)
Anatomy of the lung
-multi lobed organ
-deep red in colour
-Largest organ in the body by weight
How many lobes does a horse, cow, sheep, pig, dog and cat have?
Horse = 3
Cow = 2
Sheep = 2
Pig = 4
Dog = 4
Cat = 4
What does the gall bladder store ?
Stores bile produced by the liver.
Prior to be secreted into the duodenum of the small intestine.
Where does the hepatic artery and portal vein enter the liver?
Hepatic porta
What is the hepatic artery ?
A blood supply.
Branch of celiac artery
Supplies 25% of blood going to liver but 60% of livers O2 supply.
What is the portal vein?
A blood supply.
Blood from the stomach, spleen, pancreas and intestines
Supplies 75% of blood going to liver.
What happens with portal blood?
Is detoxified and modified within the sinusoids (capillaries) of the liver.
Then leaves via the hepatic vein which empties into the caudal vena cava and returns to heart.
What do sinusoids do?
Bring blood into contact with epithelial cells of the liver lobules.
Blood travels from periphery of the lobules towards the central vein.
What do hepatocytes do?
Produce bile.
Between hepatocytes are channels known as bile canaliculi
They carry bile from the centre of lobule to small bile ducts at the periphery of the lobule.
Bile travels from center —> periphery.
What are endothelial cells ?
Fenestrated (honey/windows) endothelial cells line the sinusoids, these cells are bound by hepatocytes.
As blood flows through sinusoid a substantial proportion of plasma is filtered into the space between the endothelial cells and the hepatocytes (space of disse)
This plasma is considerable contribution to body lymph.
What are Kupffer cells?
Phagocytes derived from macrophages (immune function) remove foreign material, tissue debris and worn out erythrocytes.
Line of defence to stop pathogens entering from the GIT reaching the systemic circulation
What are stellate cells ?
Found in space of Disse
Have a regenerative role, responding to hepatic injury of the liver.
Also the major storage site in the body for Vit A
Liver function
Carbohydrate metabolism and maintenance of normal glucose levels.
Excess glucose is stored as glycogen (glycogen es is). If blood sugar is low liver activates pathways to release glucose into the blood (glycogenolysis)
If glycogen stores are exhausted hepatocytes activates enzymes to synthesise glucose from amino acids (gluconeogenesis).
Important for carnivores as their diet is low in starch (CHO) = produce glucose from amino acids (protein)
Protein metabolism
Synthesis of glucose from amino acids.
Removal of ammonia from the body by synthesis of urea (surplus amino acids are converted by the liver to ammonia and then urea) = excreted in urine
Synthesis of non-essential amino acids - process known as transamination.
Synthesis of plasma proteins
E.g - Albumin (maintains balance of fluids in the body, fibrinogen and prothrombin involved in blood clotting, and globulins (immune function).
