Immune Health
The thymus is a lymphoid organ that is fully developed in the first months of the fetus’s gestation and that increases in size until adolescence. After this stage, its atrophying process begins, progressively decreasing, which is known as “involution of the thymus”.
The thymus fulfills various functions, including stimulating bone growth, promoting the development of the sex glands and collaborating in the development and maturation of the lymphatic system. However, its main function is the production, maturation and differentiation of T-lymphocytes or T-cells. These cells belong to the immune system and are essential to combatting different foreign antigens that can invade our body.
Currently, it has been shown that the thymus has the capacity to function and produce lymphocytes in adulthood. Until now it was thought that the thymus in adulthood had no use, since after puberty this organ regresses, considerably reducing in size, therefore the potential of the thymus as an organ with an important role in the defense of the organism even in adulthood is demonstrated.
At the same time, there is a process known as immunosenescence that results in an aging of our immune system, which suffers a loss of its ability to respond to diseases and vaccines. This phenomenon is linked to a greater number of infections in the individual and it is believed that it may influence the development of cancer or autoimmune diseases. A particularly relevant aspect is that thymic function in adults is highly heterogeneous and is related to the aging of the immune system.
Proper functioning of the organs depends on the proper functioning of their cells. Older cells tend to be less efficient with age. Also, in some organs cells die and are not replaced; therefore, the number of cells decreases. The number of cells in the testes, ovaries, liver, and kidneys decreases markedly with age. When the number of cells becomes too low, the organ does not function normally. Therefore, most organs become less efficient with age. However, not all organs lose the same number of cells. The brain is an example of that. Healthy older people don’t lose a lot of neurons.
Deterioration in the function of one organ due to disease or aging can affect the function of another organ. For example, if atherosclerosis narrows the blood vessels in the kidneys, they will decrease in function because of reduced blood flow.
Often the first signs of aging are noticed in the musculoskeletal system. Then the eyes followed by the ears begin to change in early adulthood. Most of our internal functions also decrease with age. Our bodily functions reach their highest value shortly before age 30, and from then on a gradual but steady decline begins. Despite this decline, most of the functions remain correct because most organs have a functional capacity considerably higher than that required by the body (functional reserve). For example, if half of the liver is destroyed the remaining tissue is more than enough to maintain normal function. Therefore, it is diseases rather than normal aging, that explain the loss of functional capacity in advanced ages.
Some organs are more prone to malfunction than others; These organs include the heart and blood vessels, the urinary organs (such as the kidneys), and the brain.