They are a type of cells that are part of the immune system, responsible for defending the human body from pathogenic microorganisms such as bacteria, parasites, viruses or fungi. These cells are grouped as granulocytes thanks to the fact that their structure has small granules, which inside contain chemical substances necessary to achieve phagocytosis and inflammation, important processes when it comes to defending the body, this group of cells are generated at the level of bone marrow from “myeloid” stem cells, in this group we enclose lymphocytes, monocytes and polymorphonuclear cells (neutrophils, basophils, eosinophils). Each one has specific functions.
- Neutrophil: it is the most abundant in peripheral blood, in charge of defense against bacteria in the first place and works through phagocytosis, most of these cells that circulate in the peripheral blood are segmented forms considered mature, at birth between the levels of granulocytes the neutrophil reaches up to 60% which decreases from four to six months of age, to later increase at four years of life to maintain itself in adult life.
- Eosinophil: eosinophils work in allergic reactions, parasitic infestation and chronic inflammation, and it also has the ability to engulf bacteria, eosinophil concentrations remain at 1 to 3% throughout the life of the human being.
Basophil: these work exclusively in allergic reactions in conjunction with eosinophils, these are the least abundant granulocytes in peripheral blood at an amount of 0 to 1%.
- Lymphocyte: this differs into two types, T lymphocyte is the main one in the immune response against pathogens, it generates phagocytosis and degradation of these microorganisms, two types of T lymphocytes are known, the first TCD4 lymphocyte or helpers, these present antigens, and the second TCD8 or cytotoxic lymphocytes responsible for the destruction of the antigen and the cell infected with it; on the other hand, there is the B lymphocyte, which is responsible for the generation of specific antibodies against each antigen.
- Monocyte: these act against any pathogen that generates an endotoxin that is recognized in peripheral blood, as well as being the main antigen presenters against lymphocytes, the monocyte when it is parked in a tissue is known as macrophage.
