Taste & Smell: Crash Course Anatomy & Physiology #16

Hank resists the urge to devour a slice of pizza so that he can walk you through the way we experience our major special senses. It all boils down to one thing: sensory cells translate chemical, electromagnetic, and mechanical stimuli into action potentials that our nervous system can make sense of. Today we're focusing on smell (olfaction) and taste (gustation), which are chemical senses that call on chemoreceptors. As usual, we'll begin with a quick look at how these things can go wrong.

Pssst... we made flashcards to help you review the content in this episode! Find them on the free Crash Course App!

Chapters:
Introduction: Anosmia 00:00
How Smell Works 2:13
Olfactory Epithelium 2:47
Olfactory Sensory Neurons 3:19
Glomerulus 3:47
How the Brain Processes Smell 4:48
How Taste Works 6:19
What Are Taste Buds (Taste Receptor Epithelial Cells)? 6:40
Types of Taste Receptor Epithelial Cells: Gustatory and Basal 7:53
How Different Tastants are Sensed 8:37
Review 9:28
Credits 10:05

***

Thanks to the following Patrons for their generous monthly contributions that help keep Crash Course free for everyone forever:

Mark Brouwer, Simun Niclasen, Brad Wardell, Roger C. Rocha, Jan Schmid, Elliot Beter, Nevin Spoljaric, Sandra Aft, SR Foxley, Jessica Simmons, Stefan R. Finnerup, Jason A Saslow, Robert Kunz, Jessica Wode, Mike Drew, Steve Marshall, Anna-Ester Volozh, Christian Ludvigsen, Jeffrey Thompson, James Craver, Suzanne, Dustin & Owen Mets, Amy Fuller, Simon Francis, Max Bild-Enkin, Ines Krueger, King of Conquerors Gareth Mok, Chris Ronderos, Gabriella Mayer, jeicorsair, Tokyo Coquette Boutique, Konradical the nonradical

***

Want to find Crash Course elsewhere on the internet?

[nuclearteacup]

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

[EconaelGaming]

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

[hahman]

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

[ncusick]

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!!

[whitneyempey]

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

[KemaTheAtheist]

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

[YoderJosh]

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!

[crashcourse]

Pssst... we made flashcards to help you review the content in this episode! Find them on the free Crash Course App!

[cinnamongummm]

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!

[williamfrost]

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

[username]

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!

[lungelobuthelezi]

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

[Maxseven]

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.

[darkmage]

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...!

[WorkFromHomeFriday]

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.

[NeatLedger]

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!

[oxymorono]

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

[fegolem]

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.

[christineexe]

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!

[jessiekadalon]

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!