Do you know what the thymus does?
The thymus is a primary lymphoid tissue; along with bone marrow, it is the site where T lymphocytes, components of adaptive immunity, develop. While T cells complete maturation in the thymus, B cells complete development in the bone marrow.
Secondary lymphoid tissues, on the other hand, are sites where fully developed B and T lymphocytes circulate awaiting activation by pathogens. These include the spleen, appendix, tonsil, adenoid, Peyer’s patch, etc.
Image from David B. Fankhauser, Ph.D, University of Cincinnati Clermont College

Do you know what the thymus does?

The thymus is a primary lymphoid tissue; along with bone marrow, it is the site where T lymphocytes, components of adaptive immunity, develop. While T cells complete maturation in the thymus, B cells complete development in the bone marrow.

Secondary lymphoid tissues, on the other hand, are sites where fully developed B and T lymphocytes circulate awaiting activation by pathogens. These include the spleen, appendix, tonsil, adenoid, Peyer’s patch, etc.

Image from David B. Fankhauser, Ph.D, University of Cincinnati Clermont College