The liver is one of our most important organs and the immune system of our body is a fascinating system. Would you like to learn more about both?
In this chapter you will find short descriptions and first key words to give you an overview and more insights into these subjects.
| name | greek: hepar |
| status | most essential organ for metabolism and detoxification in humans |
| location | upper right quadrant of the abdomen, below the diaphragm |
| size | largest organ in humans |
| weight | 1.500 – 2.000 g, ca. 4 % of body weight |
| composition | right hepatic lobe, left hepatic lobe |
| requirements | 28 % of the blood flow, 20 % of the total body oxygen |
| sensation of pain | - inner part of the organ is unsusceptible to pain - organ capsule is susceptible to pain, e.g. due to tension caused by organ enlargement |
| functions | - utilization of amino acids and proteins - conversion of sugar molecules into starch (energy storage) - production of energy out of fats - conversion of fats for storage - storage of starch and proteins - storage of vitamins (B12 and A) and trace elements - activation and degradation of hormones - degradation of toxins and drugs |
| products | - blood clotting factors - enzymes - hormones - bile juice (ca. 600 ml/p.d.) |
| system partners | - blood vessels - arteries - portal vein - gall bladder - bile ducts - intestine - heart |
The inflammation of the liver (= hepatitis) is a defence reaction of the immune system.
This reaction can be caused by:
Viruses causing hepatic inflammation are:
For many of the above mentioned viruses the inflammation of the liver is just one possible affected organ of the body. Only the hepatitis viruses affect primarily, but not exclusively, the liver.
The yellow fever virus also affects the liver. Infections with this virus have a high mortality rate. It is found mainly in tropical and subtropical regions in South America and Africa. A vaccination is recommended for travellers to those regions.
Other causes of hepatitis can be special bacteria and parasites.
Xenobiotics play an important role in cases of hepatitis, such as
There are different types of viral hepatitis due to different types of hepatitis viruses. They belong to different viral families not related to each other.
| Hepatitis viruses | Hepatitis A virus (HAV) | Hepatitis B virus (HBV) | Hepatitis C virus (HCV) | Hepatitis D virus (HDV) | Hepatitis E virus (HEV) |
|---|---|---|---|---|---|
| Size | 42 nm | 45 nm | |||
| Genetic information | RNA | DNA | RNA | RNA | RNA |
The hepatitis virus is composed of the following main elements:
As the virus has no innate metabolism, it uses the human cell as host cell for replication.
The hepatitis viruses replicate in the human body by
The reaction of the body against viral infections is very complex. As an early response the body produces interferons. Interferons are proteins that act as messengers in the body and play a prominent role in the defense against viruses.