How does the immune system fight an infection?

Answer 1

The immune system has an arsenal of white blood cells that engulf and kill bacteria(exept some ) and use them for a huge and bad effect on the bacteria. Calm down,the huge and bad effect will not hurt you.

Answer 2

If you've been vaccinated against the infection, eg. Tetanus, or flu vaccine, etc, you have what's called "acquired immunity". This means that when you were vaccinated with what is actaully a weaker version of the bacteria, your B-cells recognize them and produce antibodies, your T-cells then attacking and killing the antigens. Meaning that the next time your body is attacked, the B-cells will immediately recognize them and know how to respond because of it's memory.

Answer 3

The blood is composed of 3 types of cells:white blood cells, red blood cells and platelets. The white blood cells "eat" the bacteria. Some white blood cells also produce antibodies against the bacteria.

Answer 4

The immune system fights bacteria and virus by using it's white blood cells.

We have multiple kinds of white blood cells and each of those have different functions within the immune system.

We have a monocyt which can phagocytose bacteria, virusses and other xenobiotics.

We also have lymphocytes and are able to devide these into different kinds aswel.

We have a B-lymphocyt which transforms with the help of a T-helper cell(also a lymphocyt) into a plasma cell after detecting a xenobiotic. When its a plasma cell it is able to secrete antibodies spific for that xenobiotic. The first time when a b-lymphocyt gets in contact with a xenobiotic it creates a IgM antibody. This means its a antibody of M class(Ig = Immunoglobuline). These antibodies are pentamers. To make these it takes alot of time. Every other time after then, when the B-lymphocyt gets in contact with this same xenobiotic the B-lymphocyts are able to create IgG antibodies, wich are polymers, these are faster to make, and with the help of T-memorycells the B-lymphocytes can react faster to the xenobiotics.

now what the antibodies do is not destroy the xenobiotics, they only attach to it.

With this attaching antibodies it works like a marker. Monocytes and other white bloodcells like cytotoxic grannulocytes(secrete toxic into the xenobiotic to kill it) are able to detect the xenobiotic faster and react to it.

So i mentioned the cytotoxic grannulocyto which are the neutrophilic grannulocytes. The eosino and basophilic grannulocytes are for allergic reactions. for example hay fever, The eosino's and basophiles see the plant clumps as a xenobiotic and secrete histamine. This is causing the runny nose, itching eyes and shore throat. You might feel like unnecassary but this is a protection so the clumps cant enter the body anymore through nose, eyes and mouth.

Answer 5

In very general terms, the immune system will recognize the bacteria as foreign (i.e. not "self") and will mobilize itself to destroy the invaders. There are many ways that the immune system responds to infections.

The first line of defense are physical barriers (skin and the lining of lungs and digestive tract). This serves a variety of functions, mainly to block the entry of bacteria.

The second line is the so called innate immune response (natural immunity). This powerful force is responsible for identifying the infection, moving in to do its best to eliminate the infection, and to alert the rest of the immune system that something is wrong. It will do this through a variety of mechanisms. There are too many cell types for them all to be discussed here. For bacterial infections the main players are nuetrophils (what everyone thinks of as white blood cells), macrophages (literally this means big eaters), and dendritic cells (DCs). Nuetrophils are the kamikazes of your body. They charge in and attack, eat and kill everything that they see as not you, naturally this is a messy affair. Macrophages and DCs move in next to help kill the invaders, alert the rest of your immune system that something is wrong, and to start cleaning up the mess.

Most of the time your innate response is enough to eliminate the invader, but it does not have the ability to remember what its seen before. This is where your adaptive immune response comes in (you can call this acquired immunity). This part of your immune system is why vaccines work, and why its hard for you to get the same infection twice. This response is much more targeted than the natural response and therefore when you get infected with the same bug a second time you really don't feel all that sick. This response is composed of T cells (helper and killer) and B cells (the guys that produce antibodies).

For a better description of each of these parts look at Wikipedia, or head to your local library