The agranulocytes include [[Lymphocytes - Introduction|lymphocytes]] and [[Monocytes|monocytes]]. Lymphocytes differ from granulocytes and monocytes as they form part of the acquired immune response, dividing into B or T cells to fight attacks by foreign cells, bacteria and viruses. Monocytes leave the blood stream to enter tissues where they become [[Macrophages|macrophages]], which engulf bacteria and tissue debris by phagocytosis. Other cell types found in tissues include [[Mast Cells|mast cells]], which are found in mucosal and connective tissues and are granular in nature. | The agranulocytes include [[Lymphocytes - Introduction|lymphocytes]] and [[Monocytes|monocytes]]. Lymphocytes differ from granulocytes and monocytes as they form part of the acquired immune response, dividing into B or T cells to fight attacks by foreign cells, bacteria and viruses. Monocytes leave the blood stream to enter tissues where they become [[Macrophages|macrophages]], which engulf bacteria and tissue debris by phagocytosis. Other cell types found in tissues include [[Mast Cells|mast cells]], which are found in mucosal and connective tissues and are granular in nature. |