its an allergy, or an allergic reaction
An antigen is any substance that causes your immune system to produce antibodies against it. An antigen may be a foreign substance from the environment. If you get a vaccine for rubella, the antibody formed will not act against mumps (another virus).
Provides an immediate nonspecific immune response I think this is talking about the physical barriers that stop a foreign substance from entering the body. Mucous, skin, hair... those are physical barriers that stop foreign substances from entering the body. Activates T and B cells in response to an infection There are two types of T cells, helper cells which help B cells, and Killer Cells which kill foreign substances. The T cells are activated when a phagocyte eats a foreign substance and takes it to the spleen to identify what the foreign substance is. The T cells make an antigen that binds to the foreign substance so the B cells can "kill" the foreign invader. Responds to a later exposure to the same infectious agent Sam process except it is more faster then previously. The immune system creates memory B cells that remember the foreign substance and it begins immune responses to fight off the infectious agent. Distinguishes self from non self It is all about the antigens. If the person has an antibody for a flu or something, it will fight that flu that has the antigen for the flu. If it has an antibody for something that is self that is called an autoimmune response which is not good at all.
The simple answer is nothing. Allergic reactions are caused by your own immune system attacking itself. Since your immune system is your bodies defense against pathogens, and foreign objects an allergic reaction is a type of autoimmune disorder.
An immune response is based on the ability to distinguish molecules that are part of the body ("self") from those that are not ("nonself," or foreign). Such molecules that can elicit an immune response are called antigens.
Depending on the exact response, the substance is generally called a pathogen, yet more specifically depending on the nature of the response and origin of the substance, could be an antigen, allergen, carcinogen, etc.
do you mean antigens? An antigen is any (foreign) substance that stimulates an immune reaction.
When a foreign substance enters the body.
AntigenanÂ·tiÂ·gen/ËˆantijÉ™n/Noun:A toxin or other foreign substance that induces an immune response in the body, esp. the production of antibodies.
The first defense is nonspecific.
the immune system
An antigen is a foreign body. It is used as a "template" to begin an appropriate immune response.