What is the correct maturation sequence for T cells in the thymus?

The correct maturation sequence for T cells in the thymus involves several distinct phases, which aligns with the choice highlighting the maturation and selection processes occurring in the cortex, followed by migration to the medulla, and finally, the release of mature T cells into secondary lymphoid organs.

In the thymus, progenitor T cells originating from the bone marrow migrate to the cortex, where they undergo crucial steps of maturation known as positive and negative selection. Positive selection ensures that T cells can recognize self-MHC molecules, while negative selection eliminates T cells that react strongly against self-antigens, thus preventing autoimmunity. This process of education is vital for establishing a functional and self-tolerant T cell repertoire.

Once T cells have successfully undergone maturation and selection in the cortex, they migrate to the medulla for further maturation and the final selection process. After completing these stages, the mature T cells exit the thymus and enter the peripheral circulation, where they are distributed to secondary lymphoid organs such as lymph nodes and the spleen. Here, they can encounter antigens and become fully activated in response to immune challenges.

This comprehensive maturation process underscores the importance of the thymus in developing a competent and self-tolerant immune system. Other options fail to accurately