Phagocytes

Phagocytes destroy invading microorganisms by engulfing and digesting them (phagocytosis).
Neutrophils typically have a lobed nucleus and granular cytoplasm.
Neutrophils can leave the blood by squeezing through the walls of capillaries to move through tissues, engulfing any pathogens they find.
Macrophages are large phagocytes found in organs such as the lungs, liver, spleen, kidney, and lymph nodes, rather than remaining in the blood.
After being made in the bone marrow, macrophages travel in the blood as monocytes, which develop into macrophages.
Macrophages can act as antigen-presenting cells (APCs).

Lymphocytes

There are three types of lymphocytes - T-killer cells, T-helper cells, and B-lymphocytes.
T-killer cells search the body for cells that display antigens on their cell surface membrane. They then destroy the cell by poking holes in its membrane with perforins.
T-helper cells release cytokines – cell-signalling molecules that stimulate specific B lymphocytes to divide, develop into plasma cells and secrete antibodies.
Cytokines also enhance the phagocytosis of macrophages by stimulating them to become angry macrophages.
B-lymphocytes secrete antibodies specific to an antigen when mature. Some B-lymphocytes stay in the body for months or years as memory cells.