Which structure contains both B and T cells and is involved in immune response?

The lymph node is a vital structure in the immune system that plays a central role in both the activation of B and T cells and in the overall immune response. Lymph nodes serve as filtering stations for lymph, a fluid that circulates through the lymphatic system and contains various immune cells, including lymphocytes. When pathogens or foreign antigens are detected in the lymph, these nodes rapidly respond by activating the immune cells within.

B cells, which are responsible for antibody production, and T cells, which help in cell-mediated immunity, both reside in the lymph nodes. When exposed to antigens, B cells can differentiate into plasma cells to produce antibodies, while T cells can become activated to kill infected cells or help orchestrate the immune response. The organized structure of lymph nodes facilitates this interaction, creating an efficient environment for the immune response.

The spleen also plays a role in filtering blood and contains B and T cells, but it is primarily involved in the response to bloodborne pathogens rather than the overall immune response through lymphatic circulation. The thymus is essential for T cell maturation but does not contain both B and T cells in significant numbers nor is it directly involved in the immune response to pathogens. The liver is involved in various metabolic processes and immune