There are many things in Immunology that we don't know yet and it is really complicated. Let's discuss the question below!

# <center>“Why are we not allergic to everything?”</center>

<center>![](https://steemitimages.com/DQmSTsUYweGYApieiKR6EoxkeEV387HqHvhkPCDvyrHxFh7/image.png)</center>
I think, when people talk about the allergy, they will think about a body that reacts to an external substance for no reason. Am I right? There are several external substances that normally related to the reason why someone is allergic, there are dust, food, and pollen. These substance generally are not innocuous actually.Our body is trained to develop the weapon to recognize the ailment, they also destroy and block them if they coming to our body. Our immune system also know what is ours and what is not ours, they can distinguish it. For that reason, the immune system can kill the parasite, viruses, and bacteria in an effective and elegant way.

<div class="pull-right"><center><img src="https://steemitimages.com/DQmPWpvbmTiUKhR8asVwFsRAiD3L6d4y9qzsWcaGQkVF5Q6/image.png" /> <a href="https://en.wikipedia.org/wiki/Immune_system">Human Blood</a></center></div>
For this reason, that's why we're so afraid of the transplant rejection. Our immune system can recognize the organ from the other people because there is intrinsically different protein on the surface. Wait, if our immune system can recognize things or organs that not belong to our body, it will be our body enemy and it should be destroyed, but, why we're not allergic to everything? Why we're not to allergic to everything that we eat? Makes sense right? Why not it react to destroy all of those things, all of the things that we eat for example (rice, pizza, chicken, or medicine).  

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<div class="pull-left"><center><img src=https://steemitimages.com/DQmfNzGovDzPgxodPmWR4hGYtbj31cZs3S3ghP8xBQpZaH2/image.png/> <a href="https://www.theguardian.com/sport/2014/jul/09/research-shows-child-athletes-using-drugs">Medicine</a></center></div>
First of all, let we discard the medicine, medicine is a substance that not protein and it has the artificial compound. Our antibodies in our body are trained to recognize all of the protein structure, nothing invisible in our body immune system. Then, all of us like to eat chicken so much right? Chicken chop, chicken roast or KFC! But, every time we eat chicken why we don't react to them? As we know in the chicken is contain a lot of protein. I know the answer of this question "Why our body not allergic to everything" is not really clear yet, but based on what is going on right now, I will try to make the explanation okay. 

# Explanation (Immunoglobulin A & Immunoglobulin E)
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<div class="pull-right"><center><img src=https://steemitimages.com/DQmbCUKdp4xqyuWYdmaoTsqmoWYyRKed3rULUWJA3Sxg5id/image.png /> <a href="https://en.wikipedia.org/wiki/Immunoglobulin_A#cite_note-pmid17906446-5">Immunoglobulin </a></center></div>

Along with our digestive system, there is a special antibody called Immunoglobulin A or IgA, but this antibody is an antibody that is not really good to active the response of the immune system. But, IgA can block the access of any microbes or parasite in a simple way. To active a proper response another kind of Immunoglobulin is needed or called as Immunoglobulin E(IgE), there is no problem if the other kind of the Immunoglobulin not come to contact the external body.  

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<div class="pull-left"><center><img src=https://steemitimages.com/DQmSAbvXvba1j7TUMp6zVsaio478mMBw2doLZUBrxGKr7V2/image.png /> <a href="https://en.wikipedia.org/wiki/Immunoglobulin_E">Immunoglobulin</a></center></div>
Pollen and dust, most of the allergies are due to this two kinds of substance. This allergy happens caused by the effect of the response of Immunoglobulin E to kill any parasite that causing the allergy. This is very useful and better way to activate our body immune response, this will help to protect us from the internal parasites. Mastocytes, it is specific cells that dedicated to producing Histamine and this cells, Mastocytes will activate by the Immunoglobulin E. That's why you will take Antihistaminics when you are allergic. Antihistaminic is a drug, this drug is used to treat rhinitis and others allergic.  

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<div class="pull-right"><center><img src="https://steemitimages.com/DQmeKCPPq7tE64tXLSY8ereYMoj56Rv1ZAdn1qb5qyLRKRs/image.png" /> <a href="https://en.wikipedia.org/wiki/Introduction_to_viruses">Virus</a></center></div>
We are always attacked by bad stuff like the viruses and bacteria, we are always in a continuous state of inflammation every day. How many bacterial cells that you swallow every day? Bacterial cells that contain in your sandwich for your breakfast, how many? Technically, that's true that our body is reacting to everything. For your information, we are under some allergic reaction almost in every moment. We still healthy right? Yes, we're healthy because of our immune system they work really well every single day for us. For example, there also a special cell called Regulatory T-cells, most of the time this cell, T-cells will block the exaggerated allergic response that occurs in our body. 


# SUMMARY
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We are not dying every day because we only eat the food, and the food will go to our digestive system only, they don't go anywhere so, Immunoglobulin A can bind to the food that we eat. Every day, every time and also every second our body is a constant state of risk, but there also the regulative cells(T-cells) and systems will help to protect and take care of our body. Most of the molecules that are not protein or any things that no similar to anything that seen before can't be recognized. We don't really know why the allergies are only active for some molecules, and some people allergic and some are not. And why it can come and go without a reason. What you eat after you read this post, you need to think first. Whether the food that you eat can cause you allergy or not. Thanks for reading and let's continue My Biologist's Adventure. 
<center>https://youtu.be/sRMHSq2oeas</center>
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# Reference and Further Reading
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TOPIC | WEBSITES
------------ | -------------
***Wikipedia Allergy*** | <sup>https://en.wikipedia.org/wiki/Allergy</sup>
***Wikipedia Immune System*** | <sup>https://en.wikipedia.org/wiki/Immune_system</sup>
***What is Immunoglobulin A*** | <sup>https://en.wikipedia.org/wiki/Immunoglobulin_A#cite_note-pmid17906446-5</sup>
***What is Immunoglobulin E*** | <sup>https://en.wikipedia.org/wiki/Immunoglobulin_E</sup>
***Introduction of Viruses*** | <sup>https://en.wikipedia.org/wiki/Introduction_to_viruses</sup>
***What is Antihistamine*** | <sup>https://en.wikipedia.org/wiki/Antihistamine</sup>
***Wikipedia Sneeze*** | <sup>https://en.wikipedia.org/wiki/Sneeze</sup>
***Video Source*** | <sup>https://www.youtube.com/channel/UCzWQYUVCpZqtN93H8RR44Qw</sup>
***Image Source*** | <sup>https://en.wikipedia.org/wiki/Sneeze</sup>


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