Function of the liver and hepatobiliary system Flashcards
What does the liver share a blood supply with?
The intestines
What proportion of your body weight is the liver?
1/50th
How many lobes is the liver made of?
2 lobes
What divides the two lobes of the liver?
The falciform ligament
What size are the two lobes in relation to each other?
1/3 left lobe
2/3s right lobe
How is the liver held in place?
Interabdominal pressure
Peritoneum
Where is the liver located?
Right upper quadrant
What is the hylum?
Where blood enters and leaves the liver
What two further lobes are visible from the back of the liver?
Caudate lobe
Quadrate lobe
What variations in gross liver anatomy could be caused by genetic variations?
Hereditary anatomical displacement
Accessory lobes
Clefts
What variations in gross liver anatomy could come about from internal factors?
Portal thrombosis
Cardiac cirrhosis
Fibrosis
Atrophy
What variations in gross liver anatomy could come about from external factors?
Impression effects
Where does hepatic bile drain?
Directly into the duodenum
What is the common hepatic duct?
The duct which transports bile from the liver to the gall bladder
What is the common bile duct?
The duct which transports bile from the gall bladder into the duodenum
How many segments can the liver be divided into?
8 sections
Independent blood supply and bile drainage
What is the name given to the 8 sections of the liver?
Lobule
What are lobules composed of?
Hepatocytes
Sinusoidal channels
Blood vessels
Bile canalicul
What can the liver do that no other organ can?
Regenerate its own mass
Why are colon tumours commonly metastasised in the liver?
Shared blood supply
What two vessels supply the liver?
Portal vein
Hepatic artery
What percentage of the blood supply comes from the portal vein?
75%
What percentage of blood supply comes from the hepatic artery?
25%
How does blood drain from the liver?
Via hepatic vein
What surrounds the outside of the liver?
The capsule
Name four places connective tissue is found in the liver
Capsule
Perivascular
Portal tract
Reticular network
Name four extracellular matrix molecules found inside the liver
Collagens
Stellate cells
Glycoproteins
Integrins
What two roles does the ECM play
Structure
Communication
What is an acinus?
A functional unit centred on a branch of the blood input
What is a lobule?
A functional unit centred on the blood drainage
What might disrupt lobular architecture?
Fibrosis
Cirrhosis
What are hepatocytes?
60-65% of liver cells 80% of liver volume 100 billion cells Polarised polyhedral epithelial cells 20-30micro metres Low mitotic index Main functional cell
What is between two hepatocytes?
Bile canaliculi
Name 5 functions of the hepatocyte
Protein secretion Bile secretion Storage Metabolism Detoxification
What is biliary epithelium?
1-3% of liver tissue
Form collecting vessels
Polarised columnar or cuboidal epithelial cells
Dense basement membrane
What are the roles of biliary epithelium?
Transport
Secretion
What is endothelium?
Squamous epithelial cells
Barrier at the blood stream to stop entry of bacteria and viruses
Selective uptake of solutes and particles
Regulate coagulation
Regulate leukocyte traffic
What are the four endothelium of the liver?
Arterial
Venous
Lymphatic
Sinusoidal
What are kupffer cells?
Hepatic macrophages located within sinusoids 80% of all macrophages in the body Phagocytosis Produce cytokines Present antigens Regulate microcirculation Remove endotoxins
What are stellate cells?
15% of non hepatocyte cells in the liver Star shaped Store retinoids Regulate vascular diameter Responsible for fibrosis
What digestive functions does the liver have?
Carbohydrate and fat metabolism
Storage of vitamins and minerals
Where is cholesterol synthesised?
In the liver
How much bile is made a day?
0.5L
How much bile can the gall bladder hold?
100ml
What stages turn heme into bilirubin inside the macrophages?
Heme to biliverdin
Using heme oxygenase
Biliverdin to bilirubin
Using biliverdin reductase
What colour is biliverdin?
Green
What colour is bilirubin?
Orange
What is the immune function of the liver?
Protection against pathogens arriving in the blood
Phagocytosis of old or dying cells
Innate immune functions
Induction of tolerance
What is the detoxification of the liver?
Foreign compounds are broken down into water soluble products, bile and urine
What is phase 1 and 2 metabolism?
1: Oxidation
2: Conjugations
What enzymes are used in liver detoxification?
CYPs
What are the synthetic functions of the liver?
Production of useful proteins Albumin Fibronectin (coagulation) Plasminogen Transferrin Hepcidin Alpha-1 antitrypsin