What is Thymus?
{{otheruses}} The '''thymus''' is a specialized [[lymphatic system|lymphoid]] organ of the [[immune system]]. The thymus is in front of the [[heart]] and behind the [[breastbone]]. In the thymus, [[T cell]]s or T [[lymphocyte]]s mature. T cells are critical to the [[adaptive immune system]], where the body adapts specifically to foreign invaders. The thymus is where T cells develop from hematopoietic (blood-forming) cells. In addition, this is where the T cells get tolerant to cells of the body. The thymus is largest and most active during the newborn and pre-[[adolescent]] periods. By the early teens, the thymus begins to slow down. However, it continues to make [[lymphocytes]] throughout adult life. [[Category:Lymphatic system]]