Lecture 18- Liver Cells

What are the 5 types of liver cells

hepatocytes, stellate cells, Kupffer cells, liver sinusoidal endothelial cells, and cholangiocytes

What is the organization/structure of the liver?

It has hexagonal lobes with portal triads in the outer layer going towards the central hepatic vein. Oxygenated blood from the hepatic artery mixes with nutrient rich blood from the portal circulation from the gut and flows thru the sinosodial network to the central vein. Networks of bile canaliculi run parallel and counter to the blood flow thru sinusoids. Epithelial hepatocyte layer is separate from the endoderal LSEC layer by the space of Disse. Metabolic processes are structurally organized along metabolic zonations.

Liver primary functions

Excretion of: bilirubin, cholesterol, hormones, and drugs.

Metabolism of:fats, proteins,and carbs.

Regulation of: glucose+ iron

Storage of: glycogen, vitamins, and minerals

Synthesis of: plasma proteins like albumin and clotting factors like blood detoxification+purification, and bile production+excretion.

What is the inter-cell type and how does it contribute to liver scarring

Liver has some regenerative capabilities. Activated hepatic stellate cells make proliferative, fibrogenic myofibroblasts to drive hepatic fibrosis in liver injury. The response is characterized by specific phenotypic changes like proliferation, contractility, fibrogenesis, altered matrix degradation, chemotaxis and inflammatory signalling. It involves interactions between Kupffer macrophages , endothelial, and mesenchymal cells.