What is allergic rhinitis? | Respiratory system diseases | NCLEX-RN | Khan Academy
24
August

By Adem Lewis / in , , , , , , /


– [ Voiceover] So what
is Allergic Rhinitis? The part of the word “Rhin”
comes from the Greek root that means nose like in
rhinoplasty or rhinoceros. And “itis” just means inflammation. So this is an inflammation of the nose. And “allergic” just means
that it’s caused by allergies. So let’s go ahead and draw our nose here. This is the outside of the
nose, but the inside of the nose is covered with a smooth lining. And that smooth lining is called mucosa. Mucosa lines everything inside your nose. But it’s not just totally smooth in there. There’re these bones that stick
out that are called concha. They’re called concha because
they’re kind of coiled like little snail shells. So we’ll draw those in like this. This concha kind of stick out from the side of the wall of the nose. And they can take up almost
all the space in there. But in order to figure out what’s happening a little bit better, we have to zoom in. And we have to zoom in all the way to the level of the cells. So here I’m drawing some of
the cells of the nasal mucosa. And these are big globular pink cells. But there’s a couple cells
in here that are different. And these are cells of your immune system. The ones that we are worried
about, the immune cells in the nose that deal
with Allergic Rhinitis, are called mast cells and basophils. So let’s say this particular
nose and this particular set of cells has Allergic Rhinitis. What exactly is happening? Well, in Allergic Rhinitis,
like with any allergy, your body has an overreaction to some sort of stimulus in the environment. And that stimulus is called an Allergen. And let’s take a little side
note here and talk about the allergens that are
common to people who suffer from Allergic Rhinitis. The most common culprit is pollen. And pollen can come from trees, or grass. In fact, hay can cause Allergic
Rhinitis and it gives rise to one of the other
terms called Hay Fever. Although technically, Allergic
Rhinitis isn’t a fever. Pollen also tends to be seasonal. In other words, some types of
pollen are out in the Spring. Others in the Fall. And that gives rise to yet
another term that’s synonymous with Allergic Rhinitis
or seasonal allergies. Other things that can act as allergens would be mold or animal dander. But basically anything
that can get into the air that you can inhale can act
as an allergen to somebody who suffers from Allergic Rhinitis. So let’s say this nose
in this group of cells are out there in the
environment doing their thing breathing, and suck up something that’s going to act as an allergen. So that allergen goes into the nose, and that allergen is
going to come into contact with this mast cell over here. Being a mast cell or a
basophil, on its surface it has a particular protein that’s shaped a little bit like a “Y.” And that protein is
called an Immune Globulin. Which is shorten to “Ig.” And this particular
type of immune globulin is called “IgE.” There are other types of immune
globulins, “IgG” and “IgM” but for Allergic Rhinitis
we’re concerned with “IgE.” This little grain of pollen,
or whatever the allergen is. Let’s assume it’s pollen here. It’s going to get bound
by this “IgE” molecule. And that “IgE” molecule,
just a protein sitting on the surface of this basophil,
is going to alert that cell to its presence. On a normal person, the
reaction that that cell has, should be pretty minimal. It’s just a grain of pollen. It’s not like it’s an infectious agent that’s going to go in and give your body all sorts of trouble. But in a person that suffers
from Allergic Rhinitis, this cell overreacts and
it overreacts big time. And when it sees that pollen
grain it starts letting out little molecules into
its environment that tell all the cells around it
to get excited as well. So this whole group of nasal
mucosa gets overreacted. The most common type of molecule that’s used for signaling
here, is called a histamine. So now that these immune cells
are overreacting and causing all the cells around them to
overreact to this allergen, we can predict what is going
to happen inside the nose on a larger scale. Well, the first thing is that
histamine is going to cause all sorts of problems with inflammation. And that could be really sever. The mucosa can thicken up big time and get really engorged
and edematous, swollen. And that happens all throughout the nose. Because these basophils or
mast cells aren’t just sitting in one particular area. They’re scattered everywhere. I’m going to draw some of
this inflammation on these ridges in the nose, the turbinates. But it’s happening kind of everywhere. And in addition to becoming swollen, this mucosa is going to
start to overproduce mucus. And that mucus is going to
drip down along the turbinates. It’s going to drip down
the sides of the nose here. It’s going to form big drips that hang down inside your nose. It’s going to pull on the base
of your nasal cavity here. I’ll draw a few other drips of mucus. Now, I’m drawing this mucus in green, but it’s usually, actually clear. As you know, or anybody that suffers from Allergic Rhinitis knows, this can come right out your nose here. And of course, your nose
is not an isolated thing. And as this mucus pulls
in your nasal cavity, it’s going to head down this way. And that is towards your throat. So you can cough up this stuff up as well. But your throat isn’t the only thing that’s attached to your nose. In fact, there’s a tube
that lives right about here that opens up just
underneath this first ridge. Right about there. And as the mucosa swells up,
it can swell that tube shut. And that tube is called
the nasolacrimal duct. And it connects your nose to your eye. And its job is to drain
the tears out of your eye and into your nose, where
you don’t even notice them. Now, when that duct gets swollen shut, the tears don’t have anywhere to go. And that’s going to lead to watery eyes. There’s another tube that can be affected at the back of your throat. And that tube is connected to your ear. And it’s called the Eustachian tube. And similarly, if the
swelling gets bad enough, it can block off the Eustachian tube, and cause fluid to back up in this. And that’s going to lead
to symptoms with your ear. Particularly, stuffiness and
decreased ability to hear. Of course there’s also
nerves in your nose. I’ll draw one of the nerves going off to the turbinate here. These nerves ultimately end in your brain. And as they get inflamed
with all the processes that’s happening in your nose, they become irritated and
send signals to your body. Particularly, the signal to sneeze. And then if the swelling
continues to get bigger, and more pronounced, and more pronounced, it can actually completely
block off this entire nose. And when that happens,
even air can’t get by. And when air can’t get by,
breathing becomes a problem. So let’s recap the symptoms. First, you get swelling and congestion. If you block off the nasolacrimal duct, you can get watery eyes. If you block off the Eustachian tube, you can get stuffed up ears. And that nasal mucosa is
continually making mucus. And that causes nasal drip. The irritated nerves cause sneezing. And the blocked air passages, leads to difficulty
breathing through the nose. And these symptoms are going
to vary from person to person. Some people’s overreactive immune systems are severely overreactive. These symptoms are really, really bad, or they’re happening all the time. Other people may just have
a nasal drip and that’s all. Some people’s anatomy may be such, that their nasolacrimal
duct is easily blocked by just a little bit of swelling. And that can lead to
really bad watery eyes. But not much else. It all depends on the person. It can happen for a few days if you’re exposed just briefly, or it can happen year-round
if you’re allergic to many things that are always
in your environment. Additionally, sometimes it’s really easy to figure out what it is. Sometimes it’s really hard and you can’t ever pin
down exactly what it is. But, if you remember
the underline principles of an over reactive immune
cell sitting in your nose, and you know a little bit
about the anatomy of the nose, you can predict all the
symptoms that happen in this situation.


46 thoughts on “What is allergic rhinitis? | Respiratory system diseases | NCLEX-RN | Khan Academy

  1. OMG Congratulation and thank you so much for the video. I am suffering right now with this problem and everything is very clear no me now.

  2. This video helped me so much! I have all of the problems mentioned in the video, now i really know why! Thank you so much!

  3. Wow. Thank you. Now I understand my condition so much better. I'm probably allergic to pollen since whenever I go visit my parents' house I tend to sneeze a lot even though my dorm's environment is a lot dustier compared to my parent's house. Mom has a lot of plants.

  4. Thank you so much for this its BRILLIANT! you are an amazing person it really described this to be really well thank you thank you : ))

  5. people it could be much worse trust me. This is one of my more easy to deal with health problems.

  6. i have been suffered from these allergy almost couple years..I go to specialist and the dr just give me simple medicine and felt useless to me..can somebody recommend me in order to cure this problem..thanks

  7. instead of all whining about it (i get it from a protein in dust mite shit yeah lol) so basically im fucked for life i cant avoid such a tiny allergen. Anyway yeah instead of whining lets talk about treatments… nasal sprays, tablets etc. ill give you my best one… many of you probably already know about it but its the netti pot. I boil water put it in the netti pot wait for it to cool.. so its warm and i rinse my nasal passages out with it. Gets rid of the allergens and if you do it in the morning and before bed you will see a huge difference. Of course i get it all year round so i have to do this or im fucked… it may feel strange to let water go up your nose at first but you control it.. and it helps so much. Plus its not some steroid nasal spray or a tablet.. its just water yet it works so well. The netti pot give it a try if you havent already.

  8. I did not want to wait to get the Bionase so I bought a similar product called rhinitis allergy reliever. It has not helped but I would like to try the Bionase because it may be stronger.
    Buy it on Amazon and you may return it if you do not like it I think. Call and ask them.

  9. I have this but I don't have Medicare or much money. what should I do? it is very severe and is year around. I struggled in a benadryl addiction not too long ago because of this. I would take at least 8-12 a day just to stop it. It was the only thing that helped I tried everything else. I've tried Netty pots, clairatin, zyrtec, steam, nasal sprays. I even got rid of my cat 🙁. I'm constantly sneezing and blowing my nose, it's embarrassing. I've became really anti social. Because of this and because of the Benadryl I've became really quite, irratable and non talkative which is ruining my relationship I've had with my girlfriend for 7 years. I hope someone can help me figure out where to start so I can get my life back together. Thank you.

  10. I sneeze 6-10 times straight non-stop whenever I've been exposed to perfume that too sweet-smelling, dust, under air-cond or cold environment, or exposed to spicy herbs. And when after sneeze my nose becomes red, my eyes get watery and some fluid come out from my nose. I felt so ashamed to the public bcs I sneeze a lot and non-stop and ppl keep starring at me. This is so disturbing. Pls help.
    My question is, does these considered as Allergic Rhinitis?

  11. I get this every fucking day….But im not sure who the culprit is , Ive got cats and dogs in the house, pollen everywhere around the house and prolly a lot of dust mites too.

  12. Those problems just because the dramaqueens IgE's are over reacting big time. Thank God it is for me only the nose congestions but I feel for the people who are suffering more. Goodluck yall

  13. I HAVE this I smell something like medicine all the time even smoke is smelled like medicine what's the cure why the smell !?

  14. I have this and it's so annoying I'm constantly sniffling and sneezing.Like if I'm not sneezing from pollen or pet hair then I'm sneezing and having a runny nose from dust.Any suggestions on how to manage it?

  15. Can you have allergies without sneezing? I have non stop running mucus which is thin and clear and my sinuses feel swollen. My doctor is send me for allergy tests. He says he has them too.

  16. I have allergic rhinitis. I'm the one who finishes the tissue at home and my handkerchief is my lifeline. I just wanted to know if anyone else could relate…

  17. This is ruining my life. I know it sounds dramatic but anyone else who has 24-7 allergies will know how much it gets you down. It's like waking up every single day of your life with a cold. What I would give just to be able to breathe properly and not be a snivelling, dribbly, sneezing, puffy-eyed red mess 🙁 I've tried everything.

  18. Ok here is self help treatments, steaming your face, nasal irrigation with distilled water or boiled and then cooled warm water with salt. Put vaseline in your nostrils so that the allergens dont go up into respiratory system. Take black seed oil and local honey, it helps to boost the immune system, research black seed oil. Change your bedding often if your allergic to dustmites, put on anti allergy protectors on mattress and pillow. Check if you have mould growth in your house this can cause all sinus and rhinitis problems.

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