What is the Thymus?

The thymus is an internal gland located behind the upper part of the breastbone. The thymus gland, in earlier times was referred to as the "juvenilation organ". Today it is called the "the central switchboard of the body’s own defences". It has a weight of 37 grams and keeps its size until puberty. After sexual maturity, the thymus gland shrinks as life progresses.

At the age of thirty, the thymus gland has only one fourth of its original weight. This phenomenon was observed by the Greek doctor Galen in 160 AD.

The thymus gland puts hormones into the blood and is responsible for growth and immunity.

If the organism has been attacked by a disease, the thymus gland sends out lymphocytes (a special kind of white blood cell) in order to kill the intruders (germs, viruses, etc.). The gland is necessary for the production of antibodies as well as for the development of cellular defense.


Each organism has to fight constantly against an enormous number of viruses, germs, fungi, parasites and foreign substances which come from the environment.

E.g. on the surface of the skin (ca. 2 sm.) we have about 2 billion germs, in the bowel (total surface over 300 sm.) we have a concentration of approximately 10 billion germs!

The significance of the bodies own defenses is therefore obvious.

For more information about the thymus please go to the following web page: en.wikipedia.org/wiki/Thymus.