Neutrophils are normally found in the bloodstream and are the major type of phagocyte, present about 50% to 75% of the total circulating Leukocytes. One Liter of human blood contains about five billion (4-5x109) neutrophils,] which are about 6-10 µm in diameter. Once neutrophils have been activated, it takes neutrophils about 30 minutes to leave the blood stream and arrive the site of an infection. After their “work” Neutrophils do not return to the blood; they turn into pus cells and die. Mature neutrophils are smaller than monocytes, and have a segmented nucleus with several sections(two to five segments); each section is connected by chromatin filaments. In contrast to other Leukocytes the average lifespan of inactivated human neutrophils in the circulation has been reported by different approaches to be between 5 and 90 hours. After migration into the issue they survive only 24-48 hours.