LEUCOCYTES OR WHITE BLOOD CELLS (WBC)
1. 2. 3. 4. Leucocytes are colorless due to the absence of hemoglobin. Large in size than RBC's Size: 8 -15 micrometers. They possess a nucleus. Total count - 6000 to 11000/ cumm. of blood.
Divided into two types: 1. Granular Leucocytes 2. Non granular Leucocytes 1. Granular Leucocytes: The cells have granules in their cytoplasm and nucleus with two or more lobes. They are of three types: a) Eosinophils: Cells have a bilobed nucleus. They take up a red acid dye called eosin. b) Basophils: Cells take up a basic dye called methyl blue. They have a bilobed nulceus. c) Neutrophils: They take up neutral dye and have a multilobed nucleus.
2. Non granular Leucocytes: Do not have granules in their cytoplasm. They have unilobed nucleus. 1. Lymphocytes: Cells have round nucleus, scanty cytoplasm, formed in bone marrow. They are of two types: T -lymphocytes, B lymphocytes. 2. Monocytes : They have large cells with a kidney shaped nucleus.
Functions 1. Neutrophils: Provide the body with a defense against infecting microorganisms by destroying them through phagocytosis. 2. Eosinophils: They phagocytose the particles which are formed when antigen and antibodies react.
3. Basophils: They destroy the products of antigen antibody reaction. 4. Lymphocytes are responsible for development of immunity against foreign substances or antigens in the form of antibodies. 5. Monocytes: They are actively motile and phagocytose in action and they destroy the invading microorganism by phagocytosis.