Periarteriolar lymphoid sheaths (or periarterial lymphatic sheaths, or PALS) are a portion of the white pulp of the spleen.
They are populated largely by T cells and surround central arteries within the spleen; the PALS T-cells are presented with blood borne antigens via myeloid dendritic cells.
In contrast, the lymphoid portions of the white pulp are dominated by B cells.
This article related to the lymphatic system is a stub.
You can help Wikipedia by expanding it.