The cytoplasm of neutrophils is neutral in color and granular. They are spherical and the nucleus is 2-5 lobed. Their diameter is 12-15 µm. Their number is 4900 per cubic milliliter. That is the highest which is 70%. Lifespan 2-5 days. It is produced in red bone marrow. They exhibit amoeboid motility and enter the site of infection through pores in the cellular network. This process is called diapedesis. They destroy microbes by the process of phagocytosis.
Function of neutrophils
(i) They send chemical messages about microbes
(ii) Increases vascular permeability by secreting lipids
(iii) Swallows microbes by the process of phagocytosis