What happens to a foreign invader after it enters the body including the production of antibodies?
365390
It sort of depends on the invader...\n\nFor inanimate stuff--splinters of wood, glass, metal or whatever--the first thing that happens is that there is damage to cells.  Numerous compounds are released, including (but not restricted to) arachnidonic acid.  Now arachnidonic acid is converted into any one of a number of prostaglandins and leukotrienes, becoming a chemical signal that triggers a cascade of responses, including the initiation of inflammation and the attraction of an assortment of cells, including fibroblasts, macrophages and other leukocytes, and a few other critters.  Sometimes, there is enough pus formed by degenerating leukocytes that the foreign body is induced to extrude.  Other times, there is formation of a fibrous capsule around the foreign body, encapsulating it and walling it away from everything else.\n\nNow, looking at an "animate" invader, let's take the case of a bacterium...  Leukocytes are attracted to the area by substances produced locally.  Some, such as polymorphonuclear neutrophils, will actually engulf the bacteria and digest them, or at least try to (Some are too tough; mycobacteria are among 'em); macrophages will do that too.  Now, one group of leukocytes, and as I recall it that's the macrophages, will identify sections on the outside of the bacteria that look like good things to build antibodies against, and will "present" those things to lympohcytes, which will be triggered to generate antibodies against them.  As it turns out, the lymphocytes have been preprogrammed to recognize a specific appearance of object (the molecular goings on there are rather complex, but fascinating), and have just been waiting for the chance.  Antibodies will start forming; usually, the first ones will be IgM, a pentavalent antibody: it's sort of like 5 standard antibodies welded into a really big antibody.  Now, with invasion of a mucosal surface (like the lining of the nose or mouth), there is often the divalent IgA produced instead.  Either way, as the response matures, there is generation of a much more specific IgG clone--and it's the IgG antibody (monovalent, but it's Y shaped, more or less, and has two binding sites, at the ends of the arms of the Y) that is the "long term memory" antibody, for the most part.  (Where and how IgD and IgE fit into this, we're still trying to figure, although we've learned that IgE is the antibody of allergy, mainly, but also the one raised against multicellular critters, like Trichinella.)\n\nSimultaneously, of course, the cellular response is running, and as the antibody response is developing there is also the activation of the C-proteins.  That's a whole long story, but these proteins produce a cascade of response that generates an enzyme that rips holes in the outside of the bacteria's cell membrane or cell wall...\n\nThe big difference, of course, with viruses is that they actually invade cells (although Chlamydia, Chlamydophila, Ureaplasma, Mycoplasma, Rickettsia and others do so to, and are more like bacteria), and it is abnormal compounds on the outside of the infected cell that trigger the immune response.  (Some folks have hypothesized that this is one of the things that causes the association between some viral infections and autoimmune diseases, althoguh that's probably only one thing among many)\n\nMercy, I've rambled too long.  I hope that I've made some semblance of sense!!!
419756
An allergic reaction occurs due to a sensitivity to an allergen such as bees, vaccines, foods. If someone is allergic to say bees - they have generally been bitten before and their body has responded by producing antibodies. The next time they get bitten their bodies produce more of this antibody which attaches itself to the antibodies already present.  This then causes the body to release histamine etc to conteract the increase in antibodies.  As a result the person experiences things such as vasodilation (the blood vessels dilate), increased smooth muscle contraction in the lungs (makes it harder to breath) and increased mucous secretion.  In more serious cases this leads to anaphylactic shock due to the vasodilation and fluid loss.
1014480
Viruses enter your body from other bodily fluids, whether it be blood or saliva, excrement or vomit.  Viruses generally travel easier in the medium they affect, AIDS is blood-borne, and while it's possible a blood to blood transfer would infect you with a common cold or flu, it's generally spread by saliva. Generally viruses cannot survive for long outside of a host organism.\n\nYour body is under attack by viruses constantly, many times you will receive a virus and not even know because your body is able to fight it off before it can affect you. Besides the obvious, visible or physical symptoms of an infection, a doctor can test for anti-bodies to see if you've been infected. The main reason we give vaccinations is so your body can fight off a weakened or dead virus and learn to make the anti-bodies to defeat it for the next time you are infected by it. However some viruses can remain dormant for long periods of time and even tests cannot show their presence, since the viral load (amount of virus particles) is so low.  \n\nOn a side note, contrary to what was said above virus are NOT organisms. By the definitions of life it is not alive, technically it is an obligate intracellular parasite. This is for a few reasons, but the big ones are that they are not cellular based and they cannot reproduce (by themselves). They do share characteristics with living things, such as the use of DNA/RNA and the ability to evolve.
1031987
when the mosquito bites, their proboscis (the straw-like feeding device) penetrates the skin up to the subcutaneous layer of the skin beneath the dermis. When this happens, an inflammation occurs. The basophilic and mast cells (type of white blood cell) is stimulated to release HISTAMINE which contracts the smooth muscles. Since WBC uses glucose as source of energy, lactic acid is produced from glucose. Lactic acid plus the contraction of the smooth muscles plus interleukin produced by WBC gives you the ITCHINESS. The increased flow of blood in the area causes REDNESS and increase plasma concentration causes SWELLING. \n\nAnd thats how a mosquito bite itch.
1183151
The body recognizes these things, which would be allergens, as harmful foreign objects, so it attacks them, just like it does with pathogens. that's why you get all kinds of inflammation. the body doesn't know that they're in fact harmless.
389753
By blood type, tissue type, and antibodies present.  Testing will be done on the organ to make sure it viable.
348841
your body will naturally refuse anything foreign. wait it will come out on its own.
370174
They are probably a type of small, worm-like parasite living under your skin.  If you leave them, it is possible they will grow large and burst out, much like that scene in the original Alien movie where the alien bursts out of the guy's stomach.
675231
no it doesn't, you can get parasites regardless of your immune system's condition.
54342
Antigen is any substance that evokes the production of an antibody when introduced into the body. Antigens can enter the body through the respiratory tract, digestive tract, or skin. The most common antigens are proteins such as those found in/on bacteria and viruses.While an antibody Antibody, any of perhaps a million kinds of normally occurring protein molecules that are produced in the body of cells called lymphocytes and that act primarily as a defence against invasion by foreign substances. An important component of the immune system, antibodies are found in the blood of all vertebrates, in the fraction of the blood called gamma globulin.
655371
I think that the correct word you are looking for is IMMUNOGEN: "any substance or organism that provokes an immune response (produces immunity) when introduced into the body"\n\nNot all immunogens are antigens (which means "substance capable of raising antibodies against it") nor allergens ("responsible of causing allergy, a particular kind of immune response.")
476697
you get a large bump on the skin at the site of injection. it should be checked by a doctor or nurse in 2-3 days. sometimes people get false positives if they ever had a vaccine for it, especially in othr countries
414793
stem cell research (experiments on growing whole new organs from things called stem cells)\n\n\nliving donor \n\ncadaverous donor - deceased donor; most commonly from brain death\n\norgan procurement organization (OPO)\n\nharvesting\n\ndissolving stitches\n\nHyperacute rejection occurs as soon as the donated organ is in the body. This only happens if there are already antibodies in the recipient's bloodstream that react to the new organ, which would occur if the blood types of the donor and recipient were incompatible for some reason. This almost never happens, since transplant teams always test for any incompatibility ahead of time. If it were to happen, the recipient would most likely die on the operating table.  \n\nAcute rejection occurs at least a few days after the transplant, after the body has had time to recognize the foreign material. This is the normal immune response to foreign matter. \n\nChronic rejection is a very gradual rejection, lasting months or years. It can be so subtle that the patient doesn't notice any ill effects for some time. \n\n\nhttp://health.howstuffworks.com/organ-transplant.htm
366357
When you get a vaccination, you are usually being given a dead virus, or a weakened virus that won't harm you.  You body then develops antibodies to this virus.  These antibodies circulate in your blood system, usually for the rest of your life or for a given period of time and give you immunity towards the live virus if you encounter it.
148393
Usually 48-72 hours after exposure the first symptoms appear.\nShort term immunity develops after you get over it, but you can still give it to others.
121994
Dirt or foreign bodies get into areas of the body they were not meant to be. Antibodies surround the foreign body. This is the body's way of trying to expel the foreign body. When it can not be expelled, the cyst forms with a sac around it.
1177123
The germs one comes into contact with daily are familiar, assuming you spend your life in one particular geographic location, going about a regular routine. So your body gets to know those germs and learns how to defend against them, maybe even alters them in subtle ways as part of its defense. So then when you share utensils, food, etc., with another person, you are exposing yourself to unfamiliar germs, just as they are exposed to your (possibly) altered, unfamiliar germs. Your immune system has no prior information to help it fight these 'new' germs. But it will mount a defense nevertheless, and if you are relatively healthy, you will survive the encounter and your immune system will have an expanded database.