Immune system provide immunity to the body. Immune system comprises non-specific and specific immune components. Non-specific part of immune system comprises skin,tears,lysosymes etc., the name specifies that this part of the immne system cannot differentiate at molecular level but any thing and everything that is found harmfull or disturbing the homeostasis of the body will be destroyed by either enzyme activity or acidic or alkaline secretions.
Specific immune system consists of WBC or leucocytes. leucocytes are classified into two types based on granules present in the cytoplasm of the cell. Agranulocytes and granulocytes. Agranulocytes comprises Lymphocytes and Monocytes.On the other hand Granulocytes comprises Eosinophil, Basophil and Neutrophil.
Eosinophils acts on parasites, basophil(mast cells) releases histamine which raises the body temperature, neutrophil phagocytose. They identify the molecule as foreign based on the surface molecules as non self and these foreign molecules are called antigen.
Lymphocytes mainly B-lymphocytes release antibodies and monocytes mature into macrophages