Normal flora on the skin produce metabolic products that inhibit the growth of pathogenic bacteria. Gastric juice from the stomach contains hydrochloric acid as well as digestive enzymes. This process is performed by certain kinds of white blood cells or leukocytes. In this section, we will concentrate on the main phagocytic cells - the neutrophils and monocytes . These cells, which are the first ones to appear at the site of an infection, are phagocytic.
Monocytes are poorly phagocytic until stimulated to become more active by a progressing infection.
At the infection site, the neutrophils are the first phagocytes to arrive. Later the monocytes leave the bloodstream and enter the site of the infection. When they do this, the monocytes enlarge and become macrophages. Mainly, the white blood cells known as neutrophils and the monocytes are the phagocytic cells. Monocytes are poorly phagocytic until stimulated to become more active by a progressing infection.