Monmouth County's Ask The Doctor May - June 2021

The Thymus: A Forgotten, But Very Important Organ By, Lauren Kowlacki Medical science seems to be on the threshold of a revolution. It seems possible that in twenty years, doctors will be able to replace organs in the human body like parts in a car. This is thanks to the recent achievement of a team from the Medical Research Council Center for Regenerative Medicine in Edinburgh, Scotland - the group of researchers tried to regenerate the thymus gland in mice. The thymus gland is an essential organ for the development of the immune system, but very few people have any idea that it exists. The thymus gland is a small organ behind the breastbone that plays an important function both in the immune system and endocrine system. Though the thymus begins to atrophy (decay) during puberty, its effect in "training" T lymphocytesto, also known as T-cells, to fight infections and even cancer lasts for a lifetime. In the literature and also in people's awareness, the fact is often that the thymus controls and harmonizes the entire im- mune system and the immune functioning of the organism. It is the primary donor of cells for the lymphatic system, much as bone marrow is the cell donor for the cardiovascular system. It is within the thymus that progenitor cells are created and then undergo maturation and differentiation into mature T-cells. The thymus gland is located in the mediastinum, behind the sternum. It is composed of two identical lobes. Each lobe is divided into a central medulla and a peripheral cortex. The thymus is at its largest and most active during the neonatal and pre-adolescent periods. After this period the organ gradually disappears and is replaced by fat. In elderly individuals the thymus weighs 5 g. The tyhmus sheds new light on this import- ant immune defense organ, whose function is not confined to the destruction of nonfunctional T-cells. The thymus gland lies in the chest, directly behind the breastbone (sternum), and in front of the heart in the area between the lungs called the anterior mediastinum. Sometimes, however, the thymus gland is found in another (ectopic) location, such as in the neck, the thyroid gland, or on the surface of the lungs (the pleura) near the area where the blood vessels and bronchi enter the lungs. It is named the thymus due to its shape being similar to that of a thyme leaf—pyramid shaped with two lobes. The two lobes of the thymus are broken down into lobules. These lobules have an outer cortex occupied by immature T-lymphocytes, and an inner medulla occupied by mature T-lymphocytes.

ASK THE DOCTOR

SPRING 2021

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