Thymus

The thymus (Bries; in classical antiquity regarded as the seat of the mind) is an organ of the lymphatic system and thus part of the immune system. It is located cranial from the heart in the mediastinum behind the breastbone. With the onset of sexual maturity, the thymus regresses physiologically.

It develops from the 3rd throat pocket, is at first pairy, later unpaar, double-lobed. Grows until puberty begins, then gradually transforms into a fatty tissue body (except for remnants). Besides the bone marrow, the thymus is the primary lymphatic organ of the specific immune system, in which the development of immunocompetent T lymphocytes from stem cells takes place.