- What is the thymus?
- What is the function of the thymus?
- Where is the thymus?
- What problems can the thymus cause?
What is the thymus?
The thymus plays a significant role in the human immune system. In this small organ, some of the white blood cells (T lymphocytes or T cells) learn to recognize and attack foreign cells. For this purpose, the immune cells are characterized in such a way that they can distinguish the body's own surface structures (antigens) from, for example, bacteria or viruses from foreign antigens. This is important to prevent the immune cells attacking their own body and causing so-called autoimmune diseases.
The thymus consists of a right and a left lobe, both of which are surrounded by a connective tissue capsule. Connective tissue strands pass through the lobes from this capsule and subdivide the thymus into many small lobules called lobuli thymi. Each lobule consists of a bright medulla surrounded by a darker cortex.
In the medullary zone of the thymus are the characteristic Hassall bodies. Above all, they are easy to see optically under the microscope. The Hassall bodies are likely to be composed of coalesced cover tissue cells (epithelial cells) and look like little onions through this layering. Their function is not yet clear, but it is believed that they help in the maturation of immune cells.Cold? How the immune system works Every day we are exposed to countless pathogens. Learn how the defense works. Every day we are exposed to countless pathogens. Learn how the defense works.
Change of the thymus gland
The thymus is not equally active throughout life: even before birth, the thymus gland begins its work with the production and maturation of T lymphocytes.
In the newborn, the thymus cicra is five inches long and two inches wide. From childhood to puberty, the thymus reaches its maximum weight of 35 to 50 grams. From sexual maturity, the thymus gland shrinks. Function and tissue change. In old age there are predominantly fat and connective tissue, the weight is reduced to about three grams. This process is called Thymusinvolution. Most of the training of the immune cells, however, is already completed.
After its regression, the secondary lymphoid organs (lymph nodes, spleen) take over the tasks of the thymus.