How does your immune system attack bacteria, viruses, parasites, etc.?

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Humberto

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I'd like to know how your body goes about killing these things.

Please don't say it's complicated.
 
When your body detects a virus (Don't know how it does that) it send a command to your white blood cells (immune system) which instruct them to burst. When a white blood cell bursts it releases a toxin that fights and kills viruses. When the virus is stronger than the toxin, that's when you would go onto antibiotics, which then kill the virus.
 
Calvin22580 said:
When your body detects a virus (Don't know how it does that) it send a command to your white blood cells (immune system) which instruct them to burst. When a white blood cell bursts it releases a toxin that fights and kills viruses. When the virus is stronger than the toxin, that's when you would go onto antibiotics, which then kill the virus.
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Antibiotics won't help very much with viral infections, they are used for bacterial infections. You can treat viral infections with Antiviral medications, see here: https://en.wikipedia.org/wiki/Antiviral_drug

You can find some info on the human immune system on wikipedia: https://en.wikipedia.org/wiki/Immune_system
 
White blood cells literally bots with the them. If they win you live, if they don't you sue them for non-performance.
 
Sinbad said:
s/very much/at all

Antibiotics have zero effect on viruses. Which is why there's still no cure for the common cold. Or Herpes.
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Well if you believe they will work you may get some perceived relief in the form of the placebo effect. :D
 
DrJohnZoidberg said:
Well if you believe they will work you may get some perceived relief in the form of the placebo effect. :D
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LOL - but I did say "on viruses" not "on you" ;) WOuld be awesome if we could get viruses to suffer a placebo effect too....
 
Sinbad said:
s/very much/at all

Antibiotics have zero effect on viruses. Which is why there's still no cure for the common cold. Or Herpes.
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Doesn't stop some moron doctors from prescribing antibiotics for a common cold, nor the insistence by some people on receiving them...:(
 
Your body is like the house in which the white blood cells live. The germs then fight the white blood cells and whoever wins get to keep it.
 
uhm .... depends on how detailed you want the answer to be.

The immune system cascade is one of the most complex things in physiology.

Basically you need to read up on these terms:

antibody
antigen
cytokine
phagocytosis
pinocytosis
lymphocytes
macrophages
neutrophil
 
Humberto said:
I'd like to know how your body goes about killing these things.

Please don't say it's complicated.
Click to expand...
There are a variety of cells involved in immune responses. The major important ones are:

1) phagocytes (such as macrophages and neutrophils); these cells ingest other harmful cells and break them down sort of like how you ingest and break down food. They are usually present on site to react immediately to infection but they have their limits and once they have consumed a certain number of invaders they die. Some of them can also be directed to consume particular entities using antibodies.

2) helper T cells; these cells do exactly what their name implies, they help. They don't diretly do any killing, what they do is they release chemicals that act like chum for real killing immune cells, attracting them and intensifying the immune response when the helper's detect the presence of an invader. Think of them as immune response cheerleaders.

3) killer T cells; these cells are really mean buggers, they possess some very potent chemicals within them that disintegrate other cells along with a set of protein complexes that function a lot like a hypodermic needle able to penetrate through the outer coatings of harmful pathogens. Killer T cells will bind to a pathogen and drill through the outer coating in order to release the potent chemicals into that pathogen and destroy it. One of the interesting things about Killer T's is that they are the cells in your immune system best equipped to deal with some of the more difficult pathogens to combat such as viruses and cancers.

4) B cells; these cells are responsible for the production of antibodies once they are activated as (they then become known as plasma cells). For pretty much each pathogen there is a specific antibody produced that responds to that pathogen and only that pathogen. Antibodies bind to that pathogen and in doing so cover up its active sites (the areas on the pathogen that allow it to bind to, and interact with, your body through which it performs its harmful effects) thereby neutralising the pathogen. The antibodies also act as big "eat me" flags for phagocytes, attracting them and encouraging them to consume the antibody-coated invader.

5_ Memory cells; whe you encounter a pathogen for the first time not all immune cells engage in the fight, some become dormant and sit in places like your lymph nodes (read up on Wikipedia about what the lymph system is but it is sort of an overflow system for the liquid component of your blood among other things). Memory cells are these dormant cells. They live a very long time and, having been created in response to a specific pathogen, carry the knowledge of how to make specific antibodies dealing with that particular pathogen. When the memory cells again detects the pathogen later it allows your body to respond far more quickly to that pathogen through the production of new B cells already tailored specifically to fight that pathogen.

Depending on the type of pathogen present your response will be different. Antibodies for example are not effective against cancers while killer T's are somewhat effective in some circumstances (though often killer T's) aren't enough and you require medical intervention such as chemo and radiotherapy). Antibodies are great against bacterial infections for example. There are also many different types of antibodies and your body cycles through each type in turn as longa s the infection endures in an attempt to find an effective type.

Note I have simplified this a little so some of what I have said is not strictly true but will do for the purposes of a basic explanation.
 
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porchrat said:
There are a variety of cells involved in immune responses. The major important ones are:

1) phagocytes (such as macrophages and neutrophils); these cells ingest other harmful cells and break them down sort of like how you ingest and break down food. They are usually present on site to react immediately to infection but they have their limits and once they have consumed a certain number of invaders they die. Some of them can also be directed to consume particular entities using antibodies. .
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I remember this tv show(cartoon) on sundays which was about the body defence system, and I can still picture these guys that used to eat the invaders, and once full, they died. Cant remember the name of the show.
 
rh1 said:
I remember this tv show(cartoon) on sundays which was about the body defence system, and I can still picture these guys that used to eat the invaders, and once full, they died. Cant remember the name of the show.
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There was also an animated movie that was awesome, all about an entire population of self aware bacteria, cells, viruses, synapses etc living in the human body, completely unaware of the result of the sum of their actions. If anyone can remember it I'd be grateful...
 
rh1 said:
I remember this tv show(cartoon) on sundays which was about the body defence system, and I can still picture these guys that used to eat the invaders, and once full, they died. Cant remember the name of the show.
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This one?
[video=youtube;Zj6G986lpag]http://www.youtube.com/watch?v=Zj6G986lpag[/video]

Loved it when I was younger... :p.
 
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DJ... said:
Every human cell contains major histocompatibility complex molecules on its surface, which code for cell surface proteins that control the adaptive immune response. More here - http://www.biology.arizona.edu/immunology/tutorials/immunology/10t.html
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This is also tied into why people that receive donor tissue need to take immune suppressant medications initially (and in many cases permanently). The immune system recognises not just viruses and bacteria and other nasty things as foreign, but also the tissues of a transplanted organ. The immune system then attacks the organ.

Or in the case of a bone marrow transplant the immune system itself is the transplanted tissue and so often recognises the body it is transplanted into as foreign, attacking its own host body :p
 
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