ANATOMY

Detailed explanation-1: -antigen, substance that is capable of stimulating an immune response, specifically activating lymphocytes, which are the body’s infection-fighting white blood cells. In general, two main divisions of antigens are recognized: foreign antigens (or heteroantigens) and autoantigens (or self-antigens).

Detailed explanation-2: -Antigen vs antibody An antigen is a foreign substance that enters your body. This can include bacteria, viruses, fungi, allergens, venom and other various toxins. An antibody is a protein produced by your immune system to attack and fight off these antigens.

Detailed explanation-3: -Lymphocytes are the white blood cells responsible for acquired (specific) immunity, including producing antibodies (by B cells), distinguishing self from nonself (by T cells), and killing infected cells and cancer cells (by killer T cells).

Detailed explanation-4: -In summary, non-self antigens are foreign substances that trigger an immune response, self-antigens are substances that are normally present in the body and are not attacked by the immune system and allergens are a type of non-self antigen that causes an abnormal immune response known as an allergic reaction.