IMMUNOLOGY

Detailed explanation-1: -When a pathogen is recognized as foreign, chemicals called cytokines are released. A cytokine is a chemical messenger that regulates cell differentiation (form and function), proliferation (production), and gene expression to produce a variety of immune responses. Approximately 40 types of cytokines exist in humans.

Detailed explanation-2: -These cells detect antigens-proteins on the surface of pathogens which are different to the surface markers on the body’s own cells. When lymphocytes identify antigens as not belonging in the body, they produce antibodies against them. This can take a few days, during which time you may feel ill.

Detailed explanation-3: -Antibodies are protective proteins produced by your immune system. They attach to antigens (foreign substances)-such as bacteria, fungi, viruses and toxins-and remove them from your body.