| The thymus is a specialized part of the endocrine system, playing a critical role in the immune system. Within the thymus, Thymus cell lymphocytes or T cells mature. T cells are critical to the adaptive immune system, where the body adapts specifically to foreign invaders. The thymus is located in the upper front part of the chest, behind the sternum, and in front of the heart. It is made up of two lobes, each consisting of a central medulla and an outer cortex, surrounded by a capsule. |