Aging Changes in Immunity
 See all Pictures & Images
Aging changes
The thymus, one of the organs of the immune system, is the site where certain immune cells called T lymphocytes or T cells mature. The thymus begins to shrink (atrophy) after adolescence. By middle age it is only about 15% of its maximum size.
Some of the T cells directly kill foreign particles. Others help coordinate other parts of the immune system, which are specialized to attack different types of infections.
Although the number of T cells does not decrease with aging, T cell function decreases. This causes a weakening of the parts of the immune system controlled by these T cells.
|
