Cells of Liver
There are 4 basic cell types that reside in the liver:
- the hepatocyte
- the stellate fat storing cell
- the Kupffer cell
- the liver endothelial cell.
These so-called resident cells control many of the key functions in the liver, as well as its response to injury.
Hepatocytes make up about 80% of the cells in the liver.
- are large polyhedral epithelial cells, with large round centrally located nuclei (2 or more)
- grouped in interconnected plates that are arranged into thousand of small polyhedral lobules
- store glucose in the form of glycogen , also vitamin B12, folic acid and iron
- participate in the turnover and transport of lipids.
- synthesize some of the plasma proteins (albumin, α and β globulins, prothrombin, fibrinogen
- metabolize/detoxify fat
- participate in the turnover of steroid hormones.
- regulates cholesterol level
- secrete bile (up to 1 liter per day)
Ito cells (stellate cells) are cells of mesenchymal origin located in the perisinusoidal space of the liver lobules. Their cytoplasm contains large lipid droplets used to store vitamin A. Under certain pathological circumstances, e.g. after injury, alcohol damage or infection, Ito cells can differentiate into myofibroblast-like cells and synthesize excessive amounts of extracellular matrix, especially collagen type I and III. Thereby they cause fibrotization of the liver. Ito cells are also significantly involved in liver regeneration. </noinclude>
Liver as a histological preparation:
- LÜLLMANN-RAUCH, Renate. Histologie. 1. edition. Praha : Grada, 2012. 576 pp. ISBN 978-80-247-3729-4.
- MESCHER, Anthony L – JUNQUEIRA, Luiz Carlos Uchôa. Junqueira's Basic Histology. 12. edition. United States : McGraw-Hill Education - Europe, 2009. 480 pp. ISBN 9780071630207.
- VÁLEK, Vlastimil – KALA, Zdeněk, et al. Maligní ložiskové procesy jater : diagnostika a léčba včetně minimálně invazivních metod. 1. edition. Praha : Grada, 2006. ISBN 80-247-0961-9.
- specialized stellate macrophages
- adhere to the sinusoidal endothelium ( in the lumen of the sinusoid), mainly near portal areas (=portal triads)
- clear the blood of ingested bacterial pathogens that may enter portal blood from the gut
- remove aged erythrocytes and free heme for re-use
- act as antigen-presenting cells in adaptive immunity
- secret cytokines and chemokines that recruit and expand the population of other proinflammatory cells in the liver.
Sinusoidal Endothelial Cells
- form the wall of the blood vessels (sinusoids) that carry blood throughout the liver
- form a single layer with spaces between each cell known as fenestra, that allow an efficient flow of essential materials to pass from the blood to
- hepatocytes and vice versa
- are rich in lysosomal enzymes needed for degrading endocytosed material