I'm in an university psychology course and I use Hank's videos as a base to the understanding of all chapters. Thanks man!

I was born with Anosmia. The most annoying part of having anosmia is how much people forget that I can't smell.

It would've actually been funny if there was a small bite of the pizza missing after every cut to the animations :)

You have saved me and gotten me through BIO202 this semester. I can sit in a lecture for an hour and not understand a word my professor is saying. You can get the same information to me in 10 minutes and I can actually understand what you are saying. Thank you for doing what you do!!

I'm just glad to see the continued debunking of the stupid shit that was being taught when I was a kid.

I really want a behind the scenes/bloopers portion of this video XD just Hank with the pizza... I feel it would be very hilarious to watch

As an 8th grade teacher, Thank you! as a nerd, Thank you! I love that the kids I teach can see senses are far more than a standard health text book shows. I also enjoy the exposure to upper level nomenclature. Thank you!

I like the word 'umami' so much that after hearing it I started reciting it like a lunatic and completely lost focus for about a minute

Great video! Maybe I can contribute some further insight as a layman. I haven't been able to smell for over twenty years, and there are many benefits. The primary benefit is not being disgusted by pretty much anything, so I never get nauseous and I am immune to those odors that would cause ordinary people to gag etc. Vomit, feces, farts, decay, rotting food or animals cannot be smelled and therefore do not bother me. I could wade through a river of raw sewage and not be affected by the smell (not that I would lol). Getting the flu is not like it was when I could smell - it is more like a bad cold with weakness and fever, and none of the nausea and reaction to smells during a flu occur anymore. I can also interact with people without the normal distractions of body odor, bad breath, cigarette smoke or too much perfume - thus it is more pleasant and easier to engage with people, as simply people and not be burdened or offended with their smell (offensive or not). Living with, or being around people is much easier when you cannot smell. Perhaps one's impression of another is clearer, and unbiased, when the complexity of smell is removed from the equation. One could say that it was impaired too, but I don't see it that way. Another benefit is that I am not obsessed with eating all the time or "living to eat" - so weight gain and over-eating is never a problem. I do enjoy food though, because I can taste just fine. I should also point out, that the actual sense of taste (not smell), is now somehow enhanced for me. Since the input is purely taste, I can pickup subtle nuance in the pure tastes of food without the interference of smell. Another benefit is that I pretty much like every food and I don't have any aversions that are caused by powerful smells. I can't think of anything that I won't eat, sans the exotic things like grubs and insects - but I am sure I could get used to them if I lived in those parts of the world where they are the normal cuisine. I realized after many years, that when people talk about taste, most of the time they are really referring to smell. For example, saying that beets taste like dirt. Well that's not really true, it's just an expression of what people think is taste, but it is primarily smell and texture. In fact, it seems to me, that anytime someone protests certain foods, it is never about the taste, but always about the look, smell and texture. Powerful chemicals, smoke and other things like that - I cannot smell, but I can "feel" them in my nose as a sensation of burning or my eyes will react - So I am not blind to hazardous environments. I can certainly remember what things smell like, so there is a reference - and I should be clear that there are times when I wish I could smell again. Smells that I miss, like freshly cut grass, gasoline, freshly washed laundry, coffee, wine, bakeries and gourmet kitchens etc. - but in the end it is not all that bad, and one gets used to it and finds the positives to be rewarding.

I’m here because covid took away my sense of smell

I honestly love this channel so much. My teachers can be so boring and when I do ask in-depth questions, most of them tell me that it's "not in the lesson plan" and/or that I should research it on my own time. I usually forget or I never have the time BUT with the amount of information covered in just one video is impressively comprehensive and easy to access. Plus, it isn't boring to listen to :) I love the app and keep doing what you're doing!

Hey Hank! This has been one of my favorite episodes so far in this lesson series, and not only because I happen to suffer from Anosmia myself. It was enlightening to look at the senses that I personally cannot experience. I have been like this since birth, or at least as long as I can remember, and I'm just lucky enough to not have complete taste loss. Thanks for making this!

My wife had (and has) the exact same story as Olivia. It's amazing how much we rely on smell and don't realize. For Tammy, after several weeks, we did a blind taste/smell test with Lifesavers and candles to prove our theory.

It's so fast Mr. Hank!!! Awesome channel! It was so fast that taking down notes felt like playing some hardcore game! I hope that one day you'll provide us with a reading material (preferably pdfs) so that I wont have to pause/resume pause/resume the entire video to take down notes and absorb some concepts. Sorry for not as being as smart as the others. A short quiz would be nice too!

I temporarily lost my sense of smell for about a week and a half, due to a sinus infection followed by very dry sinuses. Not fun at all.

coming from someone who is Sitting in a college lecture basically a mental and emotional wreck from not understanding anything, watching these really help me to learn stuff for my tests and also make me laugh and provide helpful real life examples that i can use to help understand!

I think I'll be looking forward to this season's outtakes a lot more then usual, if only to see the ones from this particular episode. Seriously, so much willpower involved...!

I LOVE that there are different receptors for so many different smells! That's insane and beautiful.

poor olivia ;__;

My kids and I really love this channel and we are super grateful for all those making the videos, it's such a nice way to learn opposed to a textbook where we can't be sure we are pronouncing the words correctly.

the art was particulary good on this one :)

2:13-2:23 i cant do that lets all take a moment to appreciate what Hank just did

3 months after recoverd from Covid 19 - still can't smell - who's with me 😭😭😭

I just want to say, thank you for being so amazing! I'm in college, and you're videos are so helpful, and you are brilliant! Thank you so much!

These videos are all so helpful for someone struggling through their Psychology degree, I thank you

I have been waiting for this video for SO LONG!!!! I lost my sense of smell /taste when I was nine and no one understands just what that means in day to day life. Thank you for making this video!

Let me speak for the Science Olympiad kids out there: WE LOVE THESE VIDEOS

Now I want pizza :(

CrashCourse Both in the video summary and in the end of video review it says that gustation depends on four cranial nerves, but at 9:05 only 3 of them are enumerated (which is the correct number).

wait, so if I where to spend my whole life sniffing a piece of pizza, then sooner or later it will disappear?

This is the third episode I see you eating pizza !!!

thanks thought cafe if it wasent for the animations i have no idea what hankwould be saying

I love how he just say "volatile compounds" so smoothly😂

i dont even know how to thank you for all these very helpful videos. i am a biomedical sciences major and i use your videos to help me understand my biopsychology class ! you are amazing

In this video, I learned that anosmia can be caused not only by head trauma, but also through respiratory infections and aging. I also learned that each olfactory neuron has receptors for only one specific type of molecule, or smell. These signals are then sent down the axons where several axons meet up at a glomerulus. At the glomerulus, mortal cells interpret the sensory information and transfer it to the brain. The information then travels to the frontal lobe and limbic system, hypothalamus and amygdala where it triggers a powerful emotional memory. Lastly, I learned that taste is almost 80% smell, and that when you can’t smell during a cold, it becomes hard to distinguish between different types of certain flavors (such as salty, sweet, etc.).

I've been anosmic since birth, and this video has taught me more than any doctor ever has. Thank you Do you have any resources where I can learn more about the psychological and emotional effects of anosmia?

A good way to demonstrate this is to close your eyes, grab a candy like a starburst or skittle and try and guess what flavor/color it is. You'll taste a sweet, fruity flavor but you won't be able to pinpoint what it is. You'll be sure its a red starburst and then be shocked to open your eyes and find that its yellow, the worst one.

finally! updated info about the tongue and taste! this is why i love you guys, all others videos on here are completely outdated.

I usually love the Crashcourse series. This one, however, gets TASTE versus FLAVOR mixed up. Smell happens due to the nose. Taste happens due to the tongue. Flavor requires both smell and taste. So for example, a person with anosmia has no smell, has normal taste (can detect all taste qualities), but cannot detect the flavor.

I could be wrong, but I'm pretty sure receptor cells express a single odorant receptor and converge onto single glomeruli in the olfactory bulb. So those colored receptors shouldn't all go to the same glomeruli.

Well, I was TRYING to talk myself out of ordering pizza tonight. Thanks CrashCourse!

I honestly don't watch these videos to learn but because he makes boring topics interesting

I only use my nose to breathe with. Rather unfortunate, because I went one whole year smelling of sweat before someone told me.

I love Crash Course i have been watching you guys for a couple of years you guys are awesome.

These videos are actually really helping me with MCAT studying! Thanks so much

Just went through two pages of comments. It was only then I realized I was taking every opportunity to like, and post comments in agreement with, every comment declaring how gross pineapple is. I have a instinctive visceral reaction to pineapple in all its forms, whether it be pizza form or whole fruit form. Some people just don't like pineapple, I guess.

I have no sense of smell and I was really hoping this would be discussed. Thanks a lot everyone!

I'm loving this course! Learning about my brain breaks my brain though.

I don't know if anyone of you also has the same thing: I can smell an object without actually smelling it. I mean, when Hank was smelling the pizza, I also kinda... smelled the ham, cheese and so on. Not that it always happens, but I just have to focus and imagine how something smells and it's like my brain tells me that it smells the object even without it being there. Is it that my brain remembers some smells and just recalls the sensual memories of how the objects smell? It's pretty weird and I hope I described it as well as I can.

The part where Hank tells of how a badly burnt tongure will feel better after a while reminded me of something that happened to me. I got a bunch of very hot wasabi snacks and I downed them pretty quickly, but soon I found out that because they were so spicy, I couldn't taste anything for a few days. This was absolutely driving me insane, but now I wonder how that it's possible for hot and spicy food to numb the taste receptors of the tongue.

I agree. Its sort of silly that between animations he didn't take a single bit. I agree it's hard not to take a bite of pizza.

This video has made me super hungry... WHY DID I HAVE TO WATCH THIS RIGHT BEFORE LUNCH?!?

Love how I'm actually using this as revision for my year 2 medschool exams :') great video Hank, thanks very much :)

In this Crash Course, I learned: Schools still do not actually have actual scientists check the things they teach before teaching them.

Hello, CrashCourse. Just wondering: if each olfactory neuron has receptors for just one kind of smell, does that mean people who super smell like my mum have a lower threshold for action potentials to happen? or does it mean they have more olfactory neurons than most people?

I like how parts of our body, like the Glomerulus, take their names from Latin words for something obvious. I can just imagine what that person is thinking when they're naming a part that hasn't been named yet. "mmmm... this looks like a ball of yarn! but I can't name it Ballofyarn.. What's a word that sounds more cool and serious?? Let me fetch my Latin vocabulary book." sounds like me in english class as I write my essays.

trying to pay attention with the pizza there as a student is also hard. kept thinking "man I should order a pizza, that sounds fantastic"

I've red an article about umami. It was quite interesting.

Are there 3 or 4 cranial nerves that are involved in taste? Earlier Hanks mentioned 3, but he said 4 during the summary.

THIS IS AMAZING IT HELPS ME SO MUCH IN MY PHYSIOLOGY COURSE TONS OF LOVE

"We are at the aarrgh" hahah so hungry😂😂

This was the most intuitive episode of all crash cour. You guys have truly taken the art of teaching to a whole new level.

1:45 BABIES CAN DO THAT! dayum, their good

Watching this when i know I’m going to be eating pizza for dinner is the most satisfying feeling ever 😂

Do those molecules ever fall off the receptors? If so where do they go?

i cant imagine a world without Crashcource, nor pizza for that matter :)

I was going through my subscriptions checking what videos were uploaded today and this one caught my attention because I was born without a sense of smell and have never been able to smell anything all my life. I don't have a sense of smell but I am still able to taste things. I went to the doctor once when I was little so they can try and figure out why it is that I don't have a sense of smell but can taste but they didn't even have an answer for me. I get the idea of how smelling something works, but it's still difficult for me to completely understand and imagine.

I read that the mouth is the quickest part of our body to heal, and that makes sense to me... like if I mildly burn my tongue, it feels better in minutes or an hour, vs my hand hurting all day. when I bite my tongue, as long as I don't accidentally bite it again... it heals a lot faster than a cut on my finger. Is it just that injuries affecting the skin are slower to heal because the outer layer of skin is dead, or do we really heal faster in our mouths? It makes a lot of sense. My mom raised gerbils for a long time and the worst injury or illness a gerbil could get was a cut or infection in their mouth. It's not uncommon if they go too long without chewing something hard and wearing down their teeth. When your mouth hurts, you don't want to chew solid food. In the wild there aren't that many available forms of soft food for your sensitive teeth. Basically if your mouth is infected, you may die of starvation before the infection actually gets you.

Love your videos. They help so much. Thank you.

You could've talked more about the amazing wiring in the olfactory bulbs and how amazing the symmetry of these two is. And how the chemo sensing neurons send there axons through holes in the scull ^^

hangry hank has me cracking up bahaha

8:55 Hank, could I rewire someone's brain to make everything taste like poop?

I recently suffered the exact situation described in the video. I was cycling to work when I was struck by a taxi. After a few days in hospital suffering a bleed on the brain, fractured skull and heavy concussion, I suddenly found that I couldn't smell anything but what seems to be gas, and nothing has changed for almost five months now. This has not only spoiled every meal and glass of beer consumed since, but also my work as a bartender/waiter. I have to impart my beer and food knowledge to customers when asked for advice and to pair food and drink. I can't recognise subtleties in hops any more, and find myself seeking out extremes in bitter, hoppy and sour beers simply to taste a lot of something. Question: is there anything that can be done to 'retrain' by olfactory system into recognising smells again?

I'd like to know why anosmia isn't considered a disability if it is so important for sensing danger.

I'd love to see the outtakes for this episode

This was perfect info. I have a cold and can’t smell anything so I noticed I in turn cannot taste my food as much. I knew they were connected but got curious as to why/how. Thanks dude!

I temporarily lost my sense of smell a few years ago when I took a course of some antibiotic whose name I can't recall. It came back once the course of the treatment was done, but it was certainly a weird experience. Not as devastating as what that woman went through though.

Good debunking, but the cranial nerves innervate tongue in a little bit different regions, and although all tastes can be detected over the entire surface of the tongue, different regions have different thresholds for various taste This differentiation was also shown by fMRI scan, showing different local activation on the insular cortex in the response to each of the tastes encoded by taste receptors.

dose anyone else think of the old factory when you hear olfactory.

I love your episodes i swear this helps me alot with psychology ❤️❤️❤️❤️ i just wish u didnt talk so fast 😂 but u r a great teacher and very entertaining

I had hoped to find more information about smell in terms of it's function in other disorders, like PTSD. Could CrashCourse do a series of psychosomatic conditions?

how am i just finding this channel, this is a life saver!!!!!!

You crack me up. Thanks for being awesome and helping me so much throughout the years.

At 10:05 - that's me! Yay, I got animated!

3:19 😂 his voice

Love you!!! Couldn’t get through college without you!!!

Gooooood lecture

Interestingly, I heard in my physiology class that the amount of things you can smell is controversial. So it’s safe to say you can smell at least 10,000 upward to 1 trillion different kinds of smells!

In the end, I didn't learn anything. That pizza had 100 percent of my attention the entire time.

I'm sure this is asked often, but is there a way I could see a works cited for these videos? I dont know if I should be embarrassed or not, but I'm using some of these videos as part of my studies for my Masters.

+crashcourse hank u indeed have a really good self control xD

does this guy present this information off the dome? or is he reading from a teleprompter? i love these videos and watch them all the time and i must say, I'm very impressed with how fascinating he can make this

Did anyone else repeat 8:01 until they got it right? Just me? "Lava hot, melty, cheesy hotpocket"

he's not just a philosophy teacher?!! oh my god what a legend.

Here’s a great tip for all those who have trouble with how fast Hank speaks: open the video in KZfaq then click on the settings cogwheel in the corner of the screen then look for the speed setting (for me it’s near the bottom of the list) and choose a slower speed (75% or even less ). Voila!

I have total anosmia. Had it as long as I can't remember so I dont miss anything. it is annoying as hell every day tho

I taught a biochemistry class about smell literally 2 days ago :D. This was great! Thanks :)

......and Raaaaah!!!! My anatomy lectures creatively simplified

I so wanna see the outtakes for this episode.