Some of the smallest organs in the body play the largest roles. From the pituitary gland, being only the size of a pea, to the thymus gland, these small organs are involved in many different hormone pathways, many of which have yet to be fully understood. It is important to know how this gland functions and the roles it plays in both health and disease.
Anatomy
The sixth edition of the Columbia Encyclopedia states the thymus gland is a pinkish-gray mound of glandular tissue located under the upper breastbone in humans. This gland starts off the size of a newborns fist when first born and continues to grow to the size of a thin deck of cards. Once puberty starts, the tissue begins to decrease in size and blends in with the surrounding tissue.
Functions
Not much was understood about the thymus gland until the 1960s. Since then, it has become apparent that the thymus gland starts functioning as early as in the womb. This gland is responsible for development of the lymphatic system, an important part of the immune and waste removal system. According to the Columbia Encyclopedia, if the thymus is removed or fails to develop in the fetus, the whole of the immune system does not develop properly.
Hormones and Cells
The thymus gland is also responsible for helping cells take shape. The immune system has a number of white blood cells that all work together like an army to find, track and destroy foreign invaders. A large portion of the white blood cells are called lymphocytes. Lymphocytes are responsible for the initial immune response and report to the thymus to be turned into T cells. T cells are part of the white blood cells that specifically destroy germs and other foreign invaders like cancer cells. Clinton Community College states that the thymus gland not only helps turn lymphocytes into T cells but also releases thymosins, which help to further break down the division and development of T cells.
Autoimmune Disease
Since the thymus gland is responsible for developing the immune system, it can play a role in autoimmune disorders. Autoimmune diseases happen when the body no longer recognizes its own cells and begins to attack itself. A common disease associated with the thymus gland is myasthenia gravis. This disease usually starts in adults and is associated with an abnormal cluster of still-functioning cells in the gland, or a thymoma. Myasthenia gravis involves the gradual or rapid weakness of voluntary muscles, with the first ones usually being in the eyes, face and neck. This condition can effect children as well, according to the National Institutes of Health.
Cancer Research UK states other associated autoimmune conditions include systemic lupus erythematosis, rheumatoid arthritis and pernicious anemia. General treatment for these disorders, especially ones involving a thymoma, involves surgical removal of the tissue.
Cancer
Very rarely, the tissue in the thymus can become cancerous. This condition sets on much more rapidly than a thymoma and has symptoms of a cough with associated chest pain. Additionally, Cancer Research UK states a thymic carcinoma is rarely associated with autoimmune conditions. Treatment is either surgical removal or a combination of surgery, radiotherapy and chemotherapy. These carcinomas, while rare, are hard to treat, since they can rapidly spread to the lungs and lymph system.
