<unk>  <unk> <unk> n antibody playing a critical role in mucosal immunity. More<unk>  is produced than all other types of antibody combined. In its secretory form, is the main<unk> ound in mucous secretions, including tears, saliva, colostrum, intestinal juice, vaginal fluid and secretions from the prostate and respiratory epithelium. It<unk> lso found in small amounts in blood. Because it is resistant to degradation by enzymes, secretory<unk>  can survive in harsh environments such as the digestive and respiratory tracts, to provide protection against microbes that multiply in body secretions.<unk> <unk>  poor activator of the complement system, and opsonises only weakly. Its heavy chains are of the type α.
Immunoglobulin A
Immunoglobulin G
Immunoglobulin M
Immunoglobulin E
Immunoglobulin D
Gamma globulin
Immunoglobulin heavy chain
Light chain