Which veins make up the hepatic portal vein?
The portal vein carries outflow from?
How much blood does the hepatic portal vein supply to the liver?
75%
Hepatic Blood Flow
Portal-caval anastomoses
4 collateral pathways
What may happen to the portal caval anastomoses?
In portal hypertension, the collateral vessels may become engorged, dilated or varicosed.
May rupture
Normal pressure of the portal vein system?
5-8 mmHg
PORTAL HYPERTENSION
Portal Hypertension - Causes
Blockage of the portal vein before the liver, due to portal vein thrombosis or occlusion secondary to congenital portal venous abnormalities
Due to distortion of the liver architecture
i. PRESINUSOIDAL - schistosomiasis; non cirrhotic portal hypertension
ii. POSTSINUSOIDAL - cirrhosis, alcoholic hepatitis, congenital hepatic fibrosis
3. Budd-Chiari and veno occlusive disease
Budd-Chiari syndrome
Thrombosis/Occlusion of the hepatic veins draining the liver
> Congenital webs
Thrombotic tendency, protein C or S deficiency
Clinical//
• Acute
– jaundice, tender hepatomegaly
• Chronic
– Ascites
Abdo pain, ascites and liver enlargement
Diagnosis//
– US of hepatic veins
Treatment//
Wilson’s Disease
Clinical //
Treatment//
copper chelation drugs - PENICILLAMINE
ZINC
Hepatic Carcinogenesis
-INFLAMMATION
degranulation cell cycle control
DNA damage due to ROS & RNS
Cirrhosis
i) Compensated
ii) Decompensated
- Liver Failure > acute on chronic ---infection ---insult ---SIRS > End-stage liver disease --- insufficient hepatocytes ---"run out of liver"
What happens in the liver sinusoids?
Arterial and venous blood mixes
Route blood takes through the liver?
Hepatic artery and hepatic portal vein –> arterioles and venues –> sinusoids –> central vein of liver lobule –> branches of hepatic vein –> hepatic vein
Features of liver lobules
How are HEPATOCYTES arranged?
Arranged in between sinusoids in plates two cells thick
What do SINUSOIDAL SPACES contain?
> Endothelial cells
- form a fenestrated structure, allowing for free movement of solutes
> Kuppfer cells
- macrophages resident to the sinusoidal space, remove particulate matter and senescent erythrocytes
> Stellate (Ito) cells
Intrahepatic Bile System
Canaliculi -> terminal bile ductules -> perilobular ducts -> interlobular ducts -> septal ducts -> lobar ducts -> two hepatic ducts -> the common hepatic duct
Bile production between meals
Stored and concentrated in the gall bladder (sphincter of Oddi closed)
Bile production DURING a meal
How does gall bladder contract, and the sphincter of oddi open?
CCK and vagal impulses
Bile from Bile Duct Cells
Alkaline, HCO3 rich
Between meals has an ionic composition
neutralisation of chyme
pH adjustment for enzyme action
mucosal protection
Bile from HEPATOCYTES
> secreted into canaliculli > Primary bile acids - CHOLIC and CHENODEOXYCHOLIC acids > Water and electrolytes > Lipids and phospholipids > Cholesterol > IgA > Bilirubin