Blood-filtering organ
Match the lymphoid structure with its function
Peyers patch, lymphoid follicles, lymph nodes, spleen, high endothelial venues
1. Provide a concentrated and organized environment of antigen, antigen-presenting cells, T cells, and B cells in which naïve B cells and T cells can be activated
2. Capped by an M Cell which allows ready access to sample antigens from the intestine
3. Macrophages along the marginal sinuses of this blood-filtering organ clean up debris and pathogens and can then serve as antigen-presenting cells to T cells and B cells transiting the organ
4. Described as islands of dendritic cells in a sea of B cells
5. Passages or “doorways” through which B cells and T cells enter secondary lymphoid organs from the blood

