Granulocytes

They are leukocytes, with the presence of granules in their cytoplasm. The granulated cells include- eosinophil, basophil, and neutrophil.

Eosinophils

• They are the cells of leukocytes, which are present in the immune system.
• These cells are responsible for combating infections in parasites of vertebrates and for controlling mechanisms associated with allergy and asthma.
• Eosinophil cells are small granulocyte, which are produced in the bone marrow and makes 2 to 3 per cent of whole WBCs. These cells are present in high concentrations in the digestive tract.

Basophils

• They are the least common of the granulocytes, ranging from 0.5 to 1 per cent of WBCs.
• They contain large cytoplasmic granules, which play a vital role in mounting a non-specific immune response to pathogens, and allergic reactions by releasing histamine and dilating the blood vessels.
• These white blood cells have the ability to be stained when exposed to basic dyes, hence referred to as basophil.
• These cells are best known for their role in asthma and their result in inflammation and bronchoconstriction in the airways.
• They secrete serotonin, histamine and heparin.

Neutrophils

• They are normally found in the bloodstream.
• They are predominant cells, which are present in pus.
• Around 60 to 65 per cent of WBCs are neutrophils with a diameter of 10 to 12 micrometres.
• The nucleus is 2 to 5 lobed and the cytoplasm has very fine granules.
• Neutrophil helps in the destruction of bacteria with lysosomes, and it acts as a strong oxidant.
• Neutrophils are stained only using neutral dyes. Hence, they are called so.
• Neutrophils are also the first cells of the immune system to respond to an invader such as a bacteria or a virus.
• The lifespan of these WBCs extends for up to eight hours and is produced every day in the bone marrow.