April 16, 2013 • 37 mins
From Nose to Tail: Mysteries of the Mouth: Food goes on quite a fantastic journey through the human body and Stuff to Blow Your Mind is here to guide you on the way. Join Robert and Julie as they begin at digestion's base camp: a world of smell, taste, saliva and gnashing teeth.
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Speaker 1 (00:03):
Welcome to Stuff to Blow Your Mind from how Stuff
Works dot com. Hey, welcome to Stuff to Blow your Mind.
My name is Robert Lamb and Julie Douglas, and uh,
we're beginning a journey this week. The title indicates, from
nose to tail, we are going to take a fantastic
(00:25):
journey through the digestive system. Along the way, we'll even
we even talked to a special guest. And we're gonna
begin where it all starts with the nose, with the mouth,
with the entry point to the gastro intestinal highway. Yeah,
and I really wanted to try to imagine this journey
we're about to take with something that was sort of
(00:45):
a spectacular food spectacular in the sense that it would
really need a lot of digestive juices to break down.
And so immediately I thought about the hags, as this
is a sheep stomach stuffed with meat and harley. Yeah, yeah, um,
it's known as the savory pudding. It does contain sheep's pluck,
(01:06):
his heart, liver, and lungs. Obviously you are a vegetarian now,
but have you had hags? Have you not? So you've
just you've gazed at it from far well, you know,
there's a Robert Burns poem um. Yeah, and so you
know something that's celebrated in poetry you have to sort
of examine along the digestive tract, right, Yeah, I mean
(01:29):
you're digesting the digestive tract to certain extent essentially, because yes,
traditionally this this sheep's pluck, which is heart, liver, and lungs,
which is minced with onion, oatmeal, spices, and salt, uh
mixed with stock. It is all then dumped into the
lining of an animal stomach where it simmers for about
three hours. And really, I mean we everyone likes to
(01:50):
have fun with the haggests. But I mean there are
a lot of different meats and tasty dishes even that
that come from from organs and from the guts of animals.
And you know, you can make a very strong argument
that we should be eating more guts. You could. I
don't know if you should. Well, there's there's certainly a
big ethical debate there to be had as well. But
(02:11):
I mean, from the standpoint to say a dog or
a cat, that's the starting place with the guts. You
go straight for the soft meats, you go for the organs. Yeah,
and I can't make fun of it too much because
here in America we have something called her duncan. It's
just the turkey, chicken, and duck all stuffed in each other,
wrapped in an enigma. Yes, all right, So what happens
(02:32):
if you're Robert Burns and you're celebrating your favorite haggis
and you've got a fork full of it, and you're
about to put it into your mouth, Well, you're gonna
want to smell it. I mean, you are going to
smell it. There's there's there's no mistaking that, but that
This is certainly the first step. Because ultimately, when we
were talking about taste and smell, we're talking about chemical analysis.
Think of us again as less as the refined human,
(02:56):
you know, divine being that is into tasting wonderful foods
and and reading art and listening to music. Think instead
of us as the as the the evolved meat machine
that needs to consume things to steal its energy so
that it can keep going. So the first step is
analyze matter to see to what degree it can be
(03:16):
consumed and then turned into energy. Yeah, and it turns
out that the nose is actually a really huge part
of being able to taste something. Right, this is where
it all begins. It's called ortho nasal old faction, and
this is the smelling of the aromas from the outside
of the mouth. Now, only five to ten percent of
the air you inhale while breathing reaches something called the
(03:36):
old factory epiphelium, and that is located at the roof
of the nasal cavity. Okay, so if you're smelling smelling
something like across the room, you're not necessarily tasting it. No, no, um,
It's really that. The story here is that there's something
at play that is really dictating how you taste food.
And it's called retro nasal old faction. And according to
(04:00):
Mary Roach and her book Gulp of the sensory experience
of eating is old faction. And when food enters your
mouth and it begins to break down the chemical composition
to these aromatic gases, they then drift up into the
posterior narroors in the back of the mouth where they
connect with old factory receptors. So essentially, we've just had
(04:21):
this fort full of haggis enter into the mouth and
it's all those aromas are going to the back of
the throat and telling you how it is tasting before
you're even able to masticate it and chew it. So
this is step two as the meat machine had. The
meat machine has smelled the matter, found that it smells appetizing.
Now we shall touch it with the taste buds and
(04:42):
begin phase two of matter analysis. Yes, and and I
love this quote from Mary Rich's book. She says that
taste is like a doorman for the digestive tract, a
chemical skin for possible dangerous bitter sour elements and desirable
salty sweet nutrients. So she's talked about, uh, some of
the types of taste that we we have on our
(05:03):
tongue here. And that is a sweet bitter, salty sour
and your mommy, yeah, that the brothy like a karaoke
kind of a flavor. Yeah, And that is what is
lulling around your tongue. So of course you have to
start really thinking about the tongue here. And it's not
just a finger in your mouth directing food around, right,
there's a lot going on. The enzymes actually in the
(05:25):
saliva began to break food down and we'll talk more
about saliva in a moment, and they deliver them to
this rough terrain on your tongue, which is covered in
something called papali, and that is where you have your
taste bud receptors. And you have a very You've got
a ton of them. You've got fifty to one taste
cells and each taste bud receptor. And this I thought
(05:46):
was really interesting when you compare it to a catfish. Yes, yeah, yeah,
because in the book Gulp, Mary Riach talks about the
catfish is essentially one big tongue. Yeah, it's like a
swimming tongue. It comes up, it's rubbing up against something,
it's tasting it. Um. Because ultimately, when we're talking about
about taste buds, these are just these, these are just
skin cells. These are modified skin cells that have specialized
(06:08):
for a purpose. And some some animals do not have
taste buds, as she mentioned, the sperm whale, for instance,
swallow stuff whole. So it doesn't it doesn't need a doorman.
Anybody can come in. There's there's no age restriction, high restriction, etcetera.
Everyone's welcome. Um. But but then with with with humans,
we're bringing things to our lips, so it makes sense
(06:31):
for us to then have the taste buds inside our mouth.
But the catfish is swimming around in the muck just
tasting everything it touches. The house flies everyone knows when
it lands on something, it's tasting with its feet. There's
no need for it to uh to transfer the material
to a secondary source. But far more efficient, right, yeah,
far more efficient actually, I mean if we if we
(06:52):
happen to just land on our food, I'm sure the
same sort of process would be at play. Well, well,
can you imagine if everything we touched we tasted? I would,
I tell you, we would all have some very taste
neutral gloves uh and uh and slacks in our life.
Marta would be entirely just trying to imagine you it's
this overgrown fly on Morta, our local train system. Well,
(07:14):
every time I see somebody spit gum on Marta, whether
they're doing it appropriately into a trash can or inappropriately
down into the tracks, I like to think imagine if
there was a cursed piece of gum. When you're chewing it,
it tastes. It tastes just like normal gum, but where
when you spit it out, it basically becomes a taste
(07:35):
receptor and anything the gum touches you taste for the
rest of your life. That's awful. And I see that
it's a bit of a morality play going on here,
but it's you know, and that would obviously be a crazy,
um unrealistic sense world that you would then inhabit. But
these these real world examples who were looking at them,
(07:56):
the catfish, the house fly, they live in a in
a sense world we can scarcely imagine, you know, because
for us, taste is this thing we we only drag
out when we need it, we only unleash it on
the world who we need it. But with the catfish,
that the taste is its means of connecting with the
world around it. Okay, so let's imagine that this gum
(08:16):
did sort of assume the place of a tongue, right this,
this poor discarded piece of gum at the bottom of
the tracks here at the train station. Uh. It would
then send taste receptor signals to your brain, still picking
up on let's say, um, let's say there's a dog
bearinget pete on it. Uh, some of that uric acid
(08:37):
to the brain, and then your brain would say, oh, man,
I think that I have tasted this before. Oh God,
this is disgusting, or if you're Robert Burns and you're like,
well that's maybe that's a little bit like a highuess um.
That's the cool thing that's going on here is that
your tongue is delivering all of these sensory uh inputs here,
and then your brain is doing a scan and trying
(08:59):
to match it past history, but also trying to figure
out whether or not it's dangerous. Yes. And then of
course you're combining that with smell, which is an even
larger database. But of course the sense of smell is
interesting in that it it's not something we we really
think about consciously. It doesn't really connect with this consciously,
but it goes directly to the brain, and it's more
of an emotional memory response, which is why you're walking
(09:21):
down the street you smell like a weird smell and
you'll be like super nostalgic about it and uh and
you don't really know why. But taste receptors uh. The
other thing I wanted to mention that Mary Roach points
out is that we don't just have them in our mouth.
We have taste receptors in the gut, in the upper esophagus,
in the voice box, but the tongues buds are the
only ones that are hardwired to to our consciousness, right,
(09:43):
which is good because otherwise you would be picking up
on tastes like bile. Yeah, but and if correct me,
if I'm wrong, If you have or when you have
these receptors and the gut sensing things, it's more to
try to figure out if there's a bitter component to
that morsel of food, to make sure that it's not
something that's dangerous. Yes, or in some cases too it's
(10:04):
it's tied into hormonal responses as well. But but then
also it's easy to say, oh, well, if I had
if I had these taste receptors activated in my gut,
if they were actually hooked up to my conscious mind,
then I would probably be thinking, oh, that tastes gross.
But but I can only imagine that if you could
consciously taste with your gut, then the right things would
taste right, you know what I'm saying, Like, it's uh,
(10:26):
it's easy to get caught up in taste when we're
thinking about not only taste as a human experience, but
taste in other animals, other species. To think of it
from this sort of closed minded perspective of the things
that tastes good to us and the things that don't
taste good to us. But then, but ultimately, so we
said the start, it's it's chemical analysis. It's analysis of
(10:46):
matter to see if it is appropriate for transformance into food.
And it's true, and it's true. In all of this
chemical process is happening on your tongue, which, by the way,
is the hardest working muscle in your mouth, because even
when you're sleeping and still pushing saliva around and making
sure that everything is working properly. Um, And I can't
(11:07):
help keep thinking about the tongue parasite. Do you remember
samootha execua um that takes over a certain fish's tongue,
replaces it, eats it out, and then just squats there
on the tongue. Stump kind of connects in and it
becomes the tongue. It becomes a tongue. And I can't
help but think it probably does not care about taste
(11:29):
at this point, but surely it has some sort of
sensory device in place to make sure that whatever it's
picking up isn't dangerous for it A tongue within a tongue. Yeah, alright, Well,
on that note, we're going to take a quick break
and when we come back we will do some more
exploration in the mouth gnashing of teeth. All right, we're back.
(11:52):
So again we're at the we're at base camp for
the intestinal journey that goes from snout the sphincter, as
they say. So we've talked about the tongue we have.
We've talked about smell and how that plays into the
chemical analysis of matter that we are going to transform
into energy. So it it's time to talk about the
(12:14):
teeth and talk about the jaw, our means of mastication. Yeah.
And before we can even talk about that, I have
to give out a shout out to the old Ordovician period. Yeah,
because this is uh when our early vertebrate ancestors actually
transform their guilt arches into jaws. We're talking about eighty
million years ago. But if that had not happened, we
(12:37):
wouldn't even have the ability to to gnash our teeth
and to break things down and be so successful as
a species. Right, So the next time you wake in
your jaws sore from from gnashing your teeth all night,
then you can thank these ancient critters. Yeah. Or if
you're listening to this right now, grabbing some lunch or
some dinner, you know, keep that in mind, and also
keep in mind, this is really cool. And again this
(12:59):
is a revelation from the book Gulp by Mary Roach.
But the way you chew is unique to you. Um
hit me. Just grab this little quote here says there
are fast tours and slow tours, long tours and short tours,
right chewing people and left chewing people. Some of us
choose straight up and down, and others choose side to
side like cows. Your oral processing habits are a physiological fingerprint. Yeah,
(13:23):
that's crazy. I've never thought about that. I mean, I
obviously I've watched enough police investigation shows to know that
you know everyone's bite Their bite marks are individual to
them and can be used to to figure out exactly
who bit who. But but chewing as well, which have
a chew fingerprint? Yeah? Which is so you have any
unique chewing characteristics? No, I give the job done. But
(13:46):
that's about as as much as I think about it.
I know, well, I know that I chew on my
left side just because I have a dental problem on
my right side that I haven't taken care of. But Um,
it's kind of interesting to know that everybody has a
different kind of chewing rhythm going on. And I think
that speaks this idea that there are teeth are so
much more sensitive than we realize and are doing this job.
(14:09):
They can actually detect a grain of sand or grit
ten microns in diameter. And Mary Rich says that a
micron is one an inch and if you shrink a
coke can until it was the diameter of a human hair,
the letter O in the product name would be about
ten microns across. Just to give you an idea of
(14:30):
how sensitive your teeth are to what's in your mouth. Yeah,
it's crazy when you think about it, um, Like I
I often think back to the comparison between say a
chimpanzees muscles and and the humans muscles. A chimpanzee has
has more brute strength, like tremendous more brute strength than
a human, but human has has more dexterity. And when
(14:52):
when you when you look at the human mouth, there
is so much delicacy to what we can do with
it and just so much unnerving power, you know, and
you think about the things we stick in it, um,
you know, fingers, what have you, or just the fact
that our teeth are touching each other. I mean, if
if if you, like me, have had any experience grinding
(15:12):
your teeth at night, you know how self destructive the
system can be when it's not not working properly, because
there's just it's a it's a powerful set of jaws
you have there. Yeah, and your teeth are sitting there
sort of like the levee for your mouth too, because
if they weren't there, then you'd have a bunch of
saliva sort of drooling out like a one year old does.
So yeah, I mean that that's very cool that the
(15:34):
teeth are that sensitive, and then your jaw muscles are
that sensitive too, as you if you, as you said,
there's a lot of power going on there and in
terms of pressure per single burst of activity, the jaw
muscles are the strongest muscles that we have. Yeah, and
you don't even think about them being muscles for the
most part. I mean, even when they're kind of sore,
(15:55):
like like I'll find that, like I challenge anyone out
there who's not driving right now to reach up and
kind of gently massage your jaw muscles to remind yourself
that they are there and you you really start to go,
oh wow, you know there's actually some some stiffness, some
sore nous up in there, and uh it's uh, I
mean it's there's just a lot of muscle and it
(16:16):
feels delightful by the way it does. Yeah, do it
if you want to. You need to relax, rub your
your jaw muscles a little bit. Uh. And then of
course you've got all the mechanics going on. So you've
got all of that pressure per single burst going on
if you're chewing something, and it's really amazing that you
have that amount of pressure and yet your jawn can
sense and ease up at the precise moment that it
(16:38):
needs to you to make sure it doesn't come crashing
down together. Yeah, you can, Like you can pop a grape,
you can crunch a nut in your mouth and not
then destroy the teeth that are crashing together. Anything you believe.
Mary Roach also points out that anytime you're you're crunching
something in your mouth, like that's a tiny sonic boom
taking place inside your skull. Yeah. She calls it the
physics of eating. And it's really cool because your brain is, uh,
(17:01):
it's trying to get all these auditory clues about what's
going on as well, So you know, it's taking in
the input about the taste, the smell, but then yeah,
you've got the cellular walls of say, like the grape
you said, popping in your mouth, breaking down, making that
sonic boom, and telling you that this is something that's
really fresh. It's a fresh produce, it's not rotting on
(17:21):
its way out, and it's not harmful. So even something
like that, that tiny little detail is being processed. Yeah,
that's why we love crunchy things. That's why people can
eat potato chips all day because that the crunt, even
though the potato chip itself is horrible for you, the
crunch is communicating with your primordial wiring and you're thinking
(17:41):
off fresh food, fresh food, fresh food as you can't stop,
you know, popping them as you layer on processed food
after processed food into your mouth. Yeah, I mean it,
And it really gets into wine. Texture is so important food.
In our three D Printing episode, actually part two of
the three D episode three D Printing Episode, I believe,
we talked about the challenges, some of the challenges of
printing food and how they've basically sort of U tabled
(18:05):
the physical printing until they can get the taste sensations right.
But like that would be one of the big challenges
making sure that you have the right array of Christmas
and UH and other textures. It's why for me, sushi
is so amazing because you have you can you have
so many different textures going on in the food product.
But it's not just the taste but the the textual
(18:26):
It's not just the taste but the the texture as
you experience as you eat it. Yeah, and UH there's
a great chapter that's sort of tangential here, but it
talks about pet food. Oh god, that is an amazing chapter. Yeah,
and it talks about the palatants that are added to Essentially,
the palatants are what make it enticing to cats and dogs. Yeah,
it's like a liquid layer, or in some cases it's
(18:47):
powdered on. And one of the guys that she talks to,
he was previously in the uh the Cheetos business, I think,
or the Frito's one of the ohs of chips where
of course you have a standard sort of corn mush
dried husk of a thing, but then it's coated with
with some sort of delicious dust or or or liquid
(19:08):
to make it into a NonStop snacks and station, right,
So they get the texture first. They get the texture first.
And if you just eat the un h just a
naked cheeto, then it's it's gonna have no flavor. It's
just like eating cardboard, but you put the flavor on
it and then people can't resist it. And it's the
same thing with pet food. And I think it's so
(19:29):
interesting that it goes back to this idea of our
brain clocking the physics again of the food, like it
is the food ripe? Is the is the fruit good?
Is the is the produce fresh? Is it going to
make that sonic boom that my brain knows is healthy?
And then somehow that sort of got warped into the
processed food landscape. Yeah. That chapter has been one of
(19:53):
my favorites that I've I've read in the book thus
far it um because it also helps sort of show
how every animal lives in a in a different sense
world um, and how silly it is to apply human
or even individualized human taste expectations to other things. For instance,
the palatant for cat food that Mary Roach tastes. She says,
(20:16):
it basically has no flavor, but it's the but it's
the flavor coating that drives cats bananas. So the thing
that cats love tasting the most, we can't even really perceive,
which is funny when you think about those I think
it's fancy feasts as commercials where they serve up um
the meal to a big, white, fluffy cat in a
(20:36):
crystal bowl. You know, we can't help it project on.
You know that cat, like you want fifteen different flavors,
you want choices, and and no, cats don't want choices,
as she points out at as cat owners can can
also attest to cats don't want I want it mixed up.
They want the same thing. Even domestic cats that are
eating uh, wild animals. Marry Roach points out that they
(20:58):
tend to be either burgers or ouncers um and that
helps to dictate what their preferences and food choices, right, yeah, exactly. Uh.
And then to your point too, I mean, the whole
thing about the dog food cat food industry is you're
selling a product for animals, but you're selling it to humans.
So you have to find that that that crossover between
the two taste. You have to find stuff that smells
(21:21):
gross enough that dogs love it, but not so gross
that humans don't want to be around it. You have
to market to humans who want the best healthy food
for their for their pet, that that that have it
in their mind that they need a steak dinner when
really they just want to eat the delicious guts out
of something. Or on the other side of that, where
there's vegetarian kibble available for cats and dogs, when in fact,
(21:45):
especially for a cat, you know, the diet is a
meat based carnivore o G carnivore. They don't want veggies,
and you know they'll nibble on a little wheat grass
when they need a vomit. But that's about it. But
it's really interesting to see it from this side, the
marketing side, in the psychological side. Um. One of my
other favorite chapters that Mary Rich has is sort of
(22:05):
an Ode to Saliva. Yes, And I thought that was
wonderful because really it is a big player, not just
in breaking down our food but in other ways, and
so I wanted to talk about that a little bit. Okay,
so another really great chapter that Mary Rich has is
basically an Ode to Saliva, and I'm glad that she
has this chapter. Because there's so much going on in
(22:27):
your saliva. And we had touched on it briefly when
we talked about regurgitation celebration and we talked about vultures,
but it is an amazing substance. Yeah, so yeah, we're
talking about spit here, of course, and as as everyone knows,
spit is not just water. I mean, it's nine pcent water,
but there's some other important things going on, and it's
you know, think about it, like, you know, what is
(22:47):
it for? Is it? It's not just a matter of
keeping your mouth wet. It's also about getting the food wet,
breaking down the food a little bit in your mouth
before it goes down. Basically, it's involved in creating the
bullus h. So again think back to the human body
is the meat machine that must transform other matter into energy.
(23:10):
So it has smelled the food and found it appetizing.
It has tasted the food and found it appetizing. So
the next step, of course, is to chew it up,
break it down into smaller pieces, get it all nice
and wet and mucky, and transform it into a package
that can then be sent down the gut highway. And
this is the bullus right, this ball of food, this
(23:31):
massive masticated mess, masticated meat putting. Yeah, especially with the hegas. Right.
So what I love about what it's made up of
is that it's just so wildly different. So, yes, it
is mostly water, but you do have electrolytes, you have
antibacterial compounds, enzymes, which we'll talk about, and then muse
(23:53):
and mucus. Really, and the reason why you have this
mucus in your saliva or this mucin is because you
need it to be viscus unit to be able to
travel well, because it can then deliver all of those
flavors and um bits and morsels of your food to
your tongue to give it again that the sort of
um landscape that it needs to tell your brain. Hey,
(24:15):
this is what this is, because if you had a
dry tone, you wouldn't be able to taste anything essentially, Sorry,
I was thinking about my tongue. Is it sets there?
Let me tell you about other I think superhero properties
of saliva. It helps to return pH levels to normal
in your mouth. And that's really important because of course
you've got enamel on your teeth. You don't want it
to be eaten away by something. So let's say that
(24:37):
you drank something like orange juice, which is very acidic,
and the pH bubbles are high, and you drank it,
you know, morning, noon and night, couldn't get enough of it. Um. Thankfully,
when you do that, the saliva actually increases and it
helps to reduce that pH level and make it safe
inside of your mouth for your teeth actually to exist
and just crumble away. Yeah, I mean it's a portant
(25:00):
really to give your your mouth a little meat time sometimes.
You know. By what I mean by that is you've
eaten breakfast, you've brust your teeth and all that. You know,
you've mouth washed, and you've given it's been thirty minutes
since you've had your mouth washed, and maybe even an
hour doesn't mean you need to jump right back into
snacks and then brush your teeth. Like, let your mouth
have a little this normal time to to sort of settle,
(25:20):
especially when you consider that your your mouth are actually
your parroted gland produces about three pints of saliva a day.
In sevent of that saliva is something called stimulated saliva,
so it's working over time, trying to break things down
for you. Yeah, it needs a little meat time. It's important. Stuff.
(25:41):
Don't just spit it on the train station, you know.
I was. That's another thing. If people aren't spitting gummed,
then they're just spitting. When yesterday a dude was on
the train and seated, train came to a stop. He
got up from his seat, went up to the doors
when they open, spit out of the train, and then
returned to a seat. Which, on one hand, he was
nice enough to spit out of the train at a stop,
(26:01):
but still it's like, how what needed out that bag? Well,
you know, it's interesting, and this comes up in Gulp
in the book, is that it is cultural. So if
you go to certain countries, they find it disgusting to
spit into a cloth because you know, let's say they're
trying to hawk up presumably some flem from their body
and spit that out. They think it's disgusting to keep
(26:22):
that in something, So why not just spit it out?
Why would you collect it in a vessel? Yeah, I guess,
And certainly people I see people that seem to think that.
On public transportation, they spit it just directly onto the tiles. Right.
They don't really have excuses because they're not a different country. Uh,
or maybe I don't know. Maybe they're from another country
and they think they're just doing the thing they're supposed
to do. The other thing I want to talk about
(26:44):
in terms of spit, and yes, don't just go spit
it everywhere, because it really is kind of like liquid gold. Um.
I mean, I guess it's very much too like like
we're mentioned in Cornet McCarthy in a recent podcast, read
a Court McCarthy book with a bunch of cowboys in it,
and people just spitting like crazy. Every every line of dialogue,
somebody spits. But every time they do that, these wonderful
enzymes are being released. And unless they're being used for
(27:08):
a purpose, they're just flattering to the ground, then these
enzymes aren't doing any well. Yeah, it's it's a waste
of of of important resources, which is why I like
in the Doune universe among the freeman, i'd like to
to spit. You know, that's a big deal if you're
gonna spit or or weep or something, because you're the
precious liquids you're leaving that well. Yeah, because the saliva
has anti clumping properties and that discourages bacteria from rounding
(27:32):
itself up and adhering to your teeth and gums and
creating colonies. And uh, it also is something that helps
to heal wounds a lot quicker. So you'll see again
in other cultures like for instance, in Greece, you'll see
someone sort of spit on their kids wound or um.
You know, it applies spit in other areas of use,
(27:55):
and that's because of getting these antimicrobial properties that it possesses.
Well you we men, And in a previous episode, I
believe it was the vulture vomit one about the studies
that are going into looking at mothers who choose their food,
human mothers who choose their food for their their their children.
And the idea there is that you're it's the spit,
it's the key to it. Well, yeah, you're the human
(28:15):
blender for them. But also you're coating something that could
be highly allergenic. Um, you're coating those proteins and with
that saliva and you're making less allergenic for the child.
So in a way it's protecting the child as well. Um.
But I wanted to I wanted to leave this area
of this topic by looking at our laundry detergent because
(28:39):
this is a great little tidbit that came up in
the book, and I thought it was great. Mary Roach
had said, Okay, if your saliva has enzymes like amylase,
which breaks down starches to sugars, lip a's which breaks
down fats, and proteas which breaks down protein, that sounds
a lot like what's going on in your laundry and
(29:00):
your laundry detergent. And she did confirm that, in fact,
two of these are actually used in laundry detergent. And
she says that laundry detergent is essentially a digestive tract
in a box. So powerful is that saliva. Wow. I'm
not suggesting everybody just starts spinning into the washing machines now,
but you know, the next time you have a little
(29:21):
stain in your shirt, don't hesitate, you know, rub a
little spin into it. See what happens. All right, Well,
there you go. There is Ah, there's base camp for
the journey through the human body. Um, hopefully we will
we'll come back and continue this journey in future episodes
and uh and take you the rest of the way.
It only gets crazier from here. Alright. So when you
(29:42):
say crazy, I think you mean flatulence. Well, that's gonna
happen eventually, but there's always there's just a whole world.
It's a Lord of the rings Eska journey ahead of
it through the human body. All right, I'm look for it.
All right. Well, on that note, let's call over the
robot and get a little listener mail. All right, So
we are we're currently in As I am reading this,
(30:04):
we have received some emails regarding part one of the
Printer of the Gods episode, the three D Printer of
the Gods episode, but part two has not currently aired yet,
so the the emails that I have that respond to
that just bear in mind that they haven't heard part two.
So first, uh, I want to mention that we uh
we heard from a listener of the name of Lease
(30:25):
Lease Rights in and says, hi, Robert and Julie, just
listen to your three D printing episode. It's interesting stuff,
some of which I really hadn't considered before. The Devon
Tess dress was amazing, and the potential for custom fitting
is very cool. I have a common in particular about
the article on Warhammer miniatures that Robert sided. I haven't
played Warhammer in particular, but I started playing d n D.
That's dungeons and dragons, uh for you novices out there
(30:48):
in the late nineteen seventies. And I worked in a
gaming store in the early to mid nineteen eighties, and
I feel pretty comfortable saying that the article missed the
point about miniatures. Not only have people always painted them,
there's always a long history of altar them, in some
cases resculpting them to amazing degrees um with files and
epoxy and in some cases blowtorches. We're talking about lead
miniatures here, not the resin which games works up uses today. True,
(31:12):
I don't know anyone who built one from scratch, but
there are all sorts of people who have unique miniatures
which don't resemble the base models at all. It's not
merely the game changer you portray it as, at least
in the field of miniature gaming. Likewise, as far as
customizing all sorts of things in the MySpace effect, I
think it's odd to assert that this begins and ends
with three D printing. All sorts of people can and
do customize off the rack clothing, for example, and have
(31:34):
done so for years. They're even people who make their
own clothing from scratch. You might say that three D
printing makes it easier to do that, but even without
ever actually having played with a three D printer cat file,
I'd be willing to bet it still takes skill and
patience and trial and error to get it right. Although
three D printing provides new and interesting materials to play
with and uh, and it may spark a fad in
really individual and funky clothing for a while, I find
(31:56):
it hard to think that it will usher in a
new era of mass individual expread and most of the
masses just don't want to put in that much work.
If they did, they wouldn't have waited for three D
printing to do it. What it will do is provide
a different type of outlet for that really small fraction
of the people who like to make and or customize
their stuff. Cool Well, some interesting thoughts are from from
Lease now. I do want to note that a Warhammer
(32:18):
article that i U I cited they do go into
the customization a little bit, because, certainly with with miniature
gaming today, and you know it's earlier days as well,
you'll have indige individuals who buy the miniature, and the
miniature at the very least comes unassembled and unpainted. So
there are various style choices are gonna come there. Especially
it has multiple parts, uh like likewise, you can then
(32:40):
do various things to it. You can use some uh,
some putty, some uh some various other materials to change
it and make it into the thing you want. Customization,
so that that's uh to our point, that is an
important part of a miniature hobbyists. But all and also
it's again worth noting that yes, we do have the
ability to alter are our products already you can You
(33:02):
can buy clothing off the rack and then alter them
if you have the skill set to do it. But
I still think it's gonna it's gonna change things. But
we'll see how it goes. But most of the sources
I was looking at, maybe they were overselling the idea
in some cases, but I think it really a big
game changers and I think it's it was a good
analogy for for looking at the macro and micro of
its abilities to change the sort of objects we put
(33:23):
out in the world. That's just me talking from my
allergy medicine. There we cool. I also want to mention
we we did receive at least one comment from someone
who wasn't sure exactly where we stood on this whole
exchange of ideas that we see on the Internet, and
we'll be printed. So we brought intellectual property just as
(33:44):
an idea that here's another way in which intellectual property
has not been defined just such a degree that you
might have some people who were taking advantage of it.
Maybe not, We don't know. It's just a question mark. Yeah.
I mean, that's the thing about freedom is that you
freedom gives you the power to create things. It also
has it gives you the ability to u do some
(34:06):
some less advantageous things. And the example I was making
the podcast was that certainly with the Internet now you
can go out and you can steal something that is
somebody's pretty solid intellectual property. And then if we have
with with the age of three D printers, we'll be
able to steal a physical object more or less. So
that was sort of the analogy we were making. But
(34:27):
certainly not every form of sharing on the Internet is
UH is stealing just right, And I think that we're
still at a point where we're trying to figure out
what is stealing, what is sharing, what is fair use
and UH, as we had pointed out thinking the podcast
before oftentimes technologies way ahead of those sort of issues. Anyway, cool,
and then I have just a three quick uh Facebook
(34:49):
comments I wanted to read. This person comes from Meg Mega, says,
listening to the three D Printer podcasts while it work
as a miniature painter for Privateer Press, this is the
first podcast I've listened to it work that's been relevant
to my job. Looking forward to hearing more from you guys.
We also heard from uh from Critter. I don't think
this is Critter Jones, unless Critter Jones has a new
last name, so but maybe we have two listeners name Critter.
(35:12):
Either way, I like that Critter writes and says Hi,
Robert and Julie. I just listened to the interview with
Neil deGrasse Tyson and it blew my mind. I just
love hearing him talk, and so many of the questions
were in the realm of what if Uh, it was
interesting to hear him take them on. He's so intellectually honest.
I thoroughly enjoyed the episode. Please have more scientific guests
on as often as you can. I'd love to hear
(35:33):
you speak with Brian Cox, certainly perhaps about the dark
matter energy issue. And Oliver sacks Allah lepre con hallucinations.
I found them to be fascinating people to hear. Thanks
and keep up the mindful work. Well, thank you very much. Yeah. Actually,
we have an interview with Maria Roach on the books here,
so pretty soon we'll roll that out for you guys,
and we hope that you enjoy it as well. Yeah.
(35:54):
And if yeah, everyone continues to like the interviews and
they perform well, certainly we love talking to uh TO experts,
so we will will try to bring some more on
the podcast and maybe some video stuff as well. And
finally we heard from Chuck and Chuck and responding to
the three D printer says, no, not Josh and Chuck.
It's different, Chuck. There are more Chucks us, just as
(36:15):
there are more critters out there. Chuck says, cool episode, guys,
but please get the firearms terminology right. Unless you were
talking about black powder pistols, all guns are semi automatic.
I think the term you wanted to refer to was
fully automatic. It's a difference between pulling the trigger and
firing one round and pulling the trigger and firing multiple rounds.
That totally was not Chuck Bryant. Yeah, no, actually, thank
(36:38):
you for the distinction. That's really important totally. Uh So,
there you have it. A little listener mail there. We
think you think the robot as always for bringing them
over to us, and if you would like to reach
out to us and share your thoughts on the mouth,
on the tongue, on taste, on how cat's taste haagus um,
anything we talked about in this episode, let us know.
(37:00):
You can find us on Facebook and Tumbler. We are
Stuff to Blow your Mind on both of those. You
can find us on Twitter, where our handles blow the mind,
and be sure to visit our new website. We have
a website at www dot stuff to Blow your Mind
dot com, and you can always stop us online at
blow the Mind at Discovery dot com. For more on
(37:26):
this and thousands of other topics, visit how stuff works
dot com
Welcome to Stuff to Blow Your Mind from how Stuff
Works dot com. Hey, welcome to Stuff to Blow your Mind.
My name is Robert Lamb and Julie Douglas, and uh,
we're beginning a journey this week. The title indicates, from
nose to tail, we are going to take a fantastic
(00:25):
journey through the digestive system. Along the way, we'll even
we even talked to a special guest. And we're gonna
begin where it all starts with the nose, with the mouth,
with the entry point to the gastro intestinal highway. Yeah,
and I really wanted to try to imagine this journey
we're about to take with something that was sort of
(00:45):
a spectacular food spectacular in the sense that it would
really need a lot of digestive juices to break down.
And so immediately I thought about the hags, as this
is a sheep stomach stuffed with meat and harley. Yeah, yeah, um,
it's known as the savory pudding. It does contain sheep's pluck,
(01:06):
his heart, liver, and lungs. Obviously you are a vegetarian now,
but have you had hags? Have you not? So you've
just you've gazed at it from far well, you know,
there's a Robert Burns poem um. Yeah, and so you
know something that's celebrated in poetry you have to sort
of examine along the digestive tract, right, Yeah, I mean
(01:29):
you're digesting the digestive tract to certain extent essentially, because yes,
traditionally this this sheep's pluck, which is heart, liver, and lungs,
which is minced with onion, oatmeal, spices, and salt, uh
mixed with stock. It is all then dumped into the
lining of an animal stomach where it simmers for about
three hours. And really, I mean we everyone likes to
(01:50):
have fun with the haggests. But I mean there are
a lot of different meats and tasty dishes even that
that come from from organs and from the guts of animals.
And you know, you can make a very strong argument
that we should be eating more guts. You could. I
don't know if you should. Well, there's there's certainly a
big ethical debate there to be had as well. But
(02:11):
I mean, from the standpoint to say a dog or
a cat, that's the starting place with the guts. You
go straight for the soft meats, you go for the organs. Yeah,
and I can't make fun of it too much because
here in America we have something called her duncan. It's
just the turkey, chicken, and duck all stuffed in each other,
wrapped in an enigma. Yes, all right, So what happens
(02:32):
if you're Robert Burns and you're celebrating your favorite haggis
and you've got a fork full of it, and you're
about to put it into your mouth, Well, you're gonna
want to smell it. I mean, you are going to
smell it. There's there's there's no mistaking that, but that
This is certainly the first step. Because ultimately, when we
were talking about taste and smell, we're talking about chemical analysis.
Think of us again as less as the refined human,
(02:56):
you know, divine being that is into tasting wonderful foods
and and reading art and listening to music. Think instead
of us as the as the the evolved meat machine
that needs to consume things to steal its energy so
that it can keep going. So the first step is
analyze matter to see to what degree it can be
(03:16):
consumed and then turned into energy. Yeah, and it turns
out that the nose is actually a really huge part
of being able to taste something. Right, this is where
it all begins. It's called ortho nasal old faction, and
this is the smelling of the aromas from the outside
of the mouth. Now, only five to ten percent of
the air you inhale while breathing reaches something called the
(03:36):
old factory epiphelium, and that is located at the roof
of the nasal cavity. Okay, so if you're smelling smelling
something like across the room, you're not necessarily tasting it. No, no, um,
It's really that. The story here is that there's something
at play that is really dictating how you taste food.
And it's called retro nasal old faction. And according to
(04:00):
Mary Roach and her book Gulp of the sensory experience
of eating is old faction. And when food enters your
mouth and it begins to break down the chemical composition
to these aromatic gases, they then drift up into the
posterior narroors in the back of the mouth where they
connect with old factory receptors. So essentially, we've just had
(04:21):
this fort full of haggis enter into the mouth and
it's all those aromas are going to the back of
the throat and telling you how it is tasting before
you're even able to masticate it and chew it. So
this is step two as the meat machine had. The
meat machine has smelled the matter, found that it smells appetizing.
Now we shall touch it with the taste buds and
(04:42):
begin phase two of matter analysis. Yes, and and I
love this quote from Mary Rich's book. She says that
taste is like a doorman for the digestive tract, a
chemical skin for possible dangerous bitter sour elements and desirable
salty sweet nutrients. So she's talked about, uh, some of
the types of taste that we we have on our
(05:03):
tongue here. And that is a sweet bitter, salty sour
and your mommy, yeah, that the brothy like a karaoke
kind of a flavor. Yeah, And that is what is
lulling around your tongue. So of course you have to
start really thinking about the tongue here. And it's not
just a finger in your mouth directing food around, right,
there's a lot going on. The enzymes actually in the
(05:25):
saliva began to break food down and we'll talk more
about saliva in a moment, and they deliver them to
this rough terrain on your tongue, which is covered in
something called papali, and that is where you have your
taste bud receptors. And you have a very You've got
a ton of them. You've got fifty to one taste
cells and each taste bud receptor. And this I thought
(05:46):
was really interesting when you compare it to a catfish. Yes, yeah, yeah,
because in the book Gulp, Mary Riach talks about the
catfish is essentially one big tongue. Yeah, it's like a
swimming tongue. It comes up, it's rubbing up against something,
it's tasting it. Um. Because ultimately, when we're talking about
about taste buds, these are just these, these are just
skin cells. These are modified skin cells that have specialized
(06:08):
for a purpose. And some some animals do not have
taste buds, as she mentioned, the sperm whale, for instance,
swallow stuff whole. So it doesn't it doesn't need a doorman.
Anybody can come in. There's there's no age restriction, high restriction, etcetera.
Everyone's welcome. Um. But but then with with with humans,
we're bringing things to our lips, so it makes sense
(06:31):
for us to then have the taste buds inside our mouth.
But the catfish is swimming around in the muck just
tasting everything it touches. The house flies everyone knows when
it lands on something, it's tasting with its feet. There's
no need for it to uh to transfer the material
to a secondary source. But far more efficient, right, yeah,
far more efficient actually, I mean if we if we
(06:52):
happen to just land on our food, I'm sure the
same sort of process would be at play. Well, well,
can you imagine if everything we touched we tasted? I would,
I tell you, we would all have some very taste
neutral gloves uh and uh and slacks in our life.
Marta would be entirely just trying to imagine you it's
this overgrown fly on Morta, our local train system. Well,
(07:14):
every time I see somebody spit gum on Marta, whether
they're doing it appropriately into a trash can or inappropriately
down into the tracks, I like to think imagine if
there was a cursed piece of gum. When you're chewing it,
it tastes. It tastes just like normal gum, but where
when you spit it out, it basically becomes a taste
(07:35):
receptor and anything the gum touches you taste for the
rest of your life. That's awful. And I see that
it's a bit of a morality play going on here,
but it's you know, and that would obviously be a crazy,
um unrealistic sense world that you would then inhabit. But
these these real world examples who were looking at them,
(07:56):
the catfish, the house fly, they live in a in
a sense world we can scarcely imagine, you know, because
for us, taste is this thing we we only drag
out when we need it, we only unleash it on
the world who we need it. But with the catfish,
that the taste is its means of connecting with the
world around it. Okay, so let's imagine that this gum
(08:16):
did sort of assume the place of a tongue, right this,
this poor discarded piece of gum at the bottom of
the tracks here at the train station. Uh. It would
then send taste receptor signals to your brain, still picking
up on let's say, um, let's say there's a dog
bearinget pete on it. Uh, some of that uric acid
(08:37):
to the brain, and then your brain would say, oh, man,
I think that I have tasted this before. Oh God,
this is disgusting, or if you're Robert Burns and you're like,
well that's maybe that's a little bit like a highuess um.
That's the cool thing that's going on here is that
your tongue is delivering all of these sensory uh inputs here,
and then your brain is doing a scan and trying
(08:59):
to match it past history, but also trying to figure
out whether or not it's dangerous. Yes. And then of
course you're combining that with smell, which is an even
larger database. But of course the sense of smell is
interesting in that it it's not something we we really
think about consciously. It doesn't really connect with this consciously,
but it goes directly to the brain, and it's more
of an emotional memory response, which is why you're walking
(09:21):
down the street you smell like a weird smell and
you'll be like super nostalgic about it and uh and
you don't really know why. But taste receptors uh. The
other thing I wanted to mention that Mary Roach points
out is that we don't just have them in our mouth.
We have taste receptors in the gut, in the upper esophagus,
in the voice box, but the tongues buds are the
only ones that are hardwired to to our consciousness, right,
(09:43):
which is good because otherwise you would be picking up
on tastes like bile. Yeah, but and if correct me,
if I'm wrong, If you have or when you have
these receptors and the gut sensing things, it's more to
try to figure out if there's a bitter component to
that morsel of food, to make sure that it's not
something that's dangerous. Yes, or in some cases too it's
(10:04):
it's tied into hormonal responses as well. But but then
also it's easy to say, oh, well, if I had
if I had these taste receptors activated in my gut,
if they were actually hooked up to my conscious mind,
then I would probably be thinking, oh, that tastes gross.
But but I can only imagine that if you could
consciously taste with your gut, then the right things would
taste right, you know what I'm saying, Like, it's uh,
(10:26):
it's easy to get caught up in taste when we're
thinking about not only taste as a human experience, but
taste in other animals, other species. To think of it
from this sort of closed minded perspective of the things
that tastes good to us and the things that don't
taste good to us. But then, but ultimately, so we
said the start, it's it's chemical analysis. It's analysis of
(10:46):
matter to see if it is appropriate for transformance into food.
And it's true, and it's true. In all of this
chemical process is happening on your tongue, which, by the way,
is the hardest working muscle in your mouth, because even
when you're sleeping and still pushing saliva around and making
sure that everything is working properly. Um, And I can't
(11:07):
help keep thinking about the tongue parasite. Do you remember
samootha execua um that takes over a certain fish's tongue,
replaces it, eats it out, and then just squats there
on the tongue. Stump kind of connects in and it
becomes the tongue. It becomes a tongue. And I can't
help but think it probably does not care about taste
(11:29):
at this point, but surely it has some sort of
sensory device in place to make sure that whatever it's
picking up isn't dangerous for it A tongue within a tongue. Yeah, alright, Well,
on that note, we're going to take a quick break
and when we come back we will do some more
exploration in the mouth gnashing of teeth. All right, we're back.
(11:52):
So again we're at the we're at base camp for
the intestinal journey that goes from snout the sphincter, as
they say. So we've talked about the tongue we have.
We've talked about smell and how that plays into the
chemical analysis of matter that we are going to transform
into energy. So it it's time to talk about the
(12:14):
teeth and talk about the jaw, our means of mastication. Yeah.
And before we can even talk about that, I have
to give out a shout out to the old Ordovician period. Yeah,
because this is uh when our early vertebrate ancestors actually
transform their guilt arches into jaws. We're talking about eighty
million years ago. But if that had not happened, we
(12:37):
wouldn't even have the ability to to gnash our teeth
and to break things down and be so successful as
a species. Right, So the next time you wake in
your jaws sore from from gnashing your teeth all night,
then you can thank these ancient critters. Yeah. Or if
you're listening to this right now, grabbing some lunch or
some dinner, you know, keep that in mind, and also
keep in mind, this is really cool. And again this
(12:59):
is a revelation from the book Gulp by Mary Roach.
But the way you chew is unique to you. Um
hit me. Just grab this little quote here says there
are fast tours and slow tours, long tours and short tours,
right chewing people and left chewing people. Some of us
choose straight up and down, and others choose side to
side like cows. Your oral processing habits are a physiological fingerprint. Yeah,
(13:23):
that's crazy. I've never thought about that. I mean, I
obviously I've watched enough police investigation shows to know that
you know everyone's bite Their bite marks are individual to
them and can be used to to figure out exactly
who bit who. But but chewing as well, which have
a chew fingerprint? Yeah? Which is so you have any
unique chewing characteristics? No, I give the job done. But
(13:46):
that's about as as much as I think about it.
I know, well, I know that I chew on my
left side just because I have a dental problem on
my right side that I haven't taken care of. But Um,
it's kind of interesting to know that everybody has a
different kind of chewing rhythm going on. And I think
that speaks this idea that there are teeth are so
much more sensitive than we realize and are doing this job.
(14:09):
They can actually detect a grain of sand or grit
ten microns in diameter. And Mary Rich says that a
micron is one an inch and if you shrink a
coke can until it was the diameter of a human hair,
the letter O in the product name would be about
ten microns across. Just to give you an idea of
(14:30):
how sensitive your teeth are to what's in your mouth. Yeah,
it's crazy when you think about it, um, Like I
I often think back to the comparison between say a
chimpanzees muscles and and the humans muscles. A chimpanzee has
has more brute strength, like tremendous more brute strength than
a human, but human has has more dexterity. And when
(14:52):
when you when you look at the human mouth, there
is so much delicacy to what we can do with
it and just so much unnerving power, you know, and
you think about the things we stick in it, um,
you know, fingers, what have you, or just the fact
that our teeth are touching each other. I mean, if
if if you, like me, have had any experience grinding
(15:12):
your teeth at night, you know how self destructive the
system can be when it's not not working properly, because
there's just it's a it's a powerful set of jaws
you have there. Yeah, and your teeth are sitting there
sort of like the levee for your mouth too, because
if they weren't there, then you'd have a bunch of
saliva sort of drooling out like a one year old does.
So yeah, I mean that that's very cool that the
(15:34):
teeth are that sensitive, and then your jaw muscles are
that sensitive too, as you if you, as you said,
there's a lot of power going on there and in
terms of pressure per single burst of activity, the jaw
muscles are the strongest muscles that we have. Yeah, and
you don't even think about them being muscles for the
most part. I mean, even when they're kind of sore,
(15:55):
like like I'll find that, like I challenge anyone out
there who's not driving right now to reach up and
kind of gently massage your jaw muscles to remind yourself
that they are there and you you really start to go,
oh wow, you know there's actually some some stiffness, some
sore nous up in there, and uh it's uh, I
mean it's there's just a lot of muscle and it
(16:16):
feels delightful by the way it does. Yeah, do it
if you want to. You need to relax, rub your
your jaw muscles a little bit. Uh. And then of
course you've got all the mechanics going on. So you've
got all of that pressure per single burst going on
if you're chewing something, and it's really amazing that you
have that amount of pressure and yet your jawn can
sense and ease up at the precise moment that it
(16:38):
needs to you to make sure it doesn't come crashing
down together. Yeah, you can, Like you can pop a grape,
you can crunch a nut in your mouth and not
then destroy the teeth that are crashing together. Anything you believe.
Mary Roach also points out that anytime you're you're crunching
something in your mouth, like that's a tiny sonic boom
taking place inside your skull. Yeah. She calls it the
physics of eating. And it's really cool because your brain is, uh,
(17:01):
it's trying to get all these auditory clues about what's
going on as well, So you know, it's taking in
the input about the taste, the smell, but then yeah,
you've got the cellular walls of say, like the grape
you said, popping in your mouth, breaking down, making that
sonic boom, and telling you that this is something that's
really fresh. It's a fresh produce, it's not rotting on
(17:21):
its way out, and it's not harmful. So even something
like that, that tiny little detail is being processed. Yeah,
that's why we love crunchy things. That's why people can
eat potato chips all day because that the crunt, even
though the potato chip itself is horrible for you, the
crunch is communicating with your primordial wiring and you're thinking
(17:41):
off fresh food, fresh food, fresh food as you can't stop,
you know, popping them as you layer on processed food
after processed food into your mouth. Yeah, I mean it,
And it really gets into wine. Texture is so important food.
In our three D Printing episode, actually part two of
the three D episode three D Printing Episode, I believe,
we talked about the challenges, some of the challenges of
printing food and how they've basically sort of U tabled
(18:05):
the physical printing until they can get the taste sensations right.
But like that would be one of the big challenges
making sure that you have the right array of Christmas
and UH and other textures. It's why for me, sushi
is so amazing because you have you can you have
so many different textures going on in the food product.
But it's not just the taste but the the textual
(18:26):
It's not just the taste but the the texture as
you experience as you eat it. Yeah, and UH there's
a great chapter that's sort of tangential here, but it
talks about pet food. Oh god, that is an amazing chapter. Yeah,
and it talks about the palatants that are added to Essentially,
the palatants are what make it enticing to cats and dogs. Yeah,
it's like a liquid layer, or in some cases it's
(18:47):
powdered on. And one of the guys that she talks to,
he was previously in the uh the Cheetos business, I think,
or the Frito's one of the ohs of chips where
of course you have a standard sort of corn mush
dried husk of a thing, but then it's coated with
with some sort of delicious dust or or or liquid
(19:08):
to make it into a NonStop snacks and station, right,
So they get the texture first. They get the texture first.
And if you just eat the un h just a
naked cheeto, then it's it's gonna have no flavor. It's
just like eating cardboard, but you put the flavor on
it and then people can't resist it. And it's the
same thing with pet food. And I think it's so
(19:29):
interesting that it goes back to this idea of our
brain clocking the physics again of the food, like it
is the food ripe? Is the is the fruit good?
Is the is the produce fresh? Is it going to
make that sonic boom that my brain knows is healthy?
And then somehow that sort of got warped into the
processed food landscape. Yeah. That chapter has been one of
(19:53):
my favorites that I've I've read in the book thus
far it um because it also helps sort of show
how every animal lives in a in a different sense
world um, and how silly it is to apply human
or even individualized human taste expectations to other things. For instance,
the palatant for cat food that Mary Roach tastes. She says,
(20:16):
it basically has no flavor, but it's the but it's
the flavor coating that drives cats bananas. So the thing
that cats love tasting the most, we can't even really perceive,
which is funny when you think about those I think
it's fancy feasts as commercials where they serve up um
the meal to a big, white, fluffy cat in a
(20:36):
crystal bowl. You know, we can't help it project on.
You know that cat, like you want fifteen different flavors,
you want choices, and and no, cats don't want choices,
as she points out at as cat owners can can
also attest to cats don't want I want it mixed up.
They want the same thing. Even domestic cats that are
eating uh, wild animals. Marry Roach points out that they
(20:58):
tend to be either burgers or ouncers um and that
helps to dictate what their preferences and food choices, right, yeah, exactly. Uh.
And then to your point too, I mean, the whole
thing about the dog food cat food industry is you're
selling a product for animals, but you're selling it to humans.
So you have to find that that that crossover between
the two taste. You have to find stuff that smells
(21:21):
gross enough that dogs love it, but not so gross
that humans don't want to be around it. You have
to market to humans who want the best healthy food
for their for their pet, that that that have it
in their mind that they need a steak dinner when
really they just want to eat the delicious guts out
of something. Or on the other side of that, where
there's vegetarian kibble available for cats and dogs, when in fact,
(21:45):
especially for a cat, you know, the diet is a
meat based carnivore o G carnivore. They don't want veggies,
and you know they'll nibble on a little wheat grass
when they need a vomit. But that's about it. But
it's really interesting to see it from this side, the
marketing side, in the psychological side. Um. One of my
other favorite chapters that Mary Rich has is sort of
(22:05):
an Ode to Saliva. Yes, And I thought that was
wonderful because really it is a big player, not just
in breaking down our food but in other ways, and
so I wanted to talk about that a little bit. Okay,
so another really great chapter that Mary Rich has is
basically an Ode to Saliva, and I'm glad that she
has this chapter. Because there's so much going on in
(22:27):
your saliva. And we had touched on it briefly when
we talked about regurgitation celebration and we talked about vultures,
but it is an amazing substance. Yeah, so yeah, we're
talking about spit here, of course, and as as everyone knows,
spit is not just water. I mean, it's nine pcent water,
but there's some other important things going on, and it's
you know, think about it, like, you know, what is
(22:47):
it for? Is it? It's not just a matter of
keeping your mouth wet. It's also about getting the food wet,
breaking down the food a little bit in your mouth
before it goes down. Basically, it's involved in creating the
bullus h. So again think back to the human body
is the meat machine that must transform other matter into energy.
(23:10):
So it has smelled the food and found it appetizing.
It has tasted the food and found it appetizing. So
the next step, of course, is to chew it up,
break it down into smaller pieces, get it all nice
and wet and mucky, and transform it into a package
that can then be sent down the gut highway. And
this is the bullus right, this ball of food, this
(23:31):
massive masticated mess, masticated meat putting. Yeah, especially with the hegas. Right.
So what I love about what it's made up of
is that it's just so wildly different. So, yes, it
is mostly water, but you do have electrolytes, you have
antibacterial compounds, enzymes, which we'll talk about, and then muse
(23:53):
and mucus. Really, and the reason why you have this
mucus in your saliva or this mucin is because you
need it to be viscus unit to be able to
travel well, because it can then deliver all of those
flavors and um bits and morsels of your food to
your tongue to give it again that the sort of
um landscape that it needs to tell your brain. Hey,
(24:15):
this is what this is, because if you had a
dry tone, you wouldn't be able to taste anything essentially, Sorry,
I was thinking about my tongue. Is it sets there?
Let me tell you about other I think superhero properties
of saliva. It helps to return pH levels to normal
in your mouth. And that's really important because of course
you've got enamel on your teeth. You don't want it
to be eaten away by something. So let's say that
(24:37):
you drank something like orange juice, which is very acidic,
and the pH bubbles are high, and you drank it,
you know, morning, noon and night, couldn't get enough of it. Um. Thankfully,
when you do that, the saliva actually increases and it
helps to reduce that pH level and make it safe
inside of your mouth for your teeth actually to exist
and just crumble away. Yeah, I mean it's a portant
(25:00):
really to give your your mouth a little meat time sometimes.
You know. By what I mean by that is you've
eaten breakfast, you've brust your teeth and all that. You know,
you've mouth washed, and you've given it's been thirty minutes
since you've had your mouth washed, and maybe even an
hour doesn't mean you need to jump right back into
snacks and then brush your teeth. Like, let your mouth
have a little this normal time to to sort of settle,
(25:20):
especially when you consider that your your mouth are actually
your parroted gland produces about three pints of saliva a day.
In sevent of that saliva is something called stimulated saliva,
so it's working over time, trying to break things down
for you. Yeah, it needs a little meat time. It's important. Stuff.
(25:41):
Don't just spit it on the train station, you know.
I was. That's another thing. If people aren't spitting gummed,
then they're just spitting. When yesterday a dude was on
the train and seated, train came to a stop. He
got up from his seat, went up to the doors
when they open, spit out of the train, and then
returned to a seat. Which, on one hand, he was
nice enough to spit out of the train at a stop,
(26:01):
but still it's like, how what needed out that bag? Well,
you know, it's interesting, and this comes up in Gulp
in the book, is that it is cultural. So if
you go to certain countries, they find it disgusting to
spit into a cloth because you know, let's say they're
trying to hawk up presumably some flem from their body
and spit that out. They think it's disgusting to keep
(26:22):
that in something, So why not just spit it out?
Why would you collect it in a vessel? Yeah, I guess,
And certainly people I see people that seem to think that.
On public transportation, they spit it just directly onto the tiles. Right.
They don't really have excuses because they're not a different country. Uh,
or maybe I don't know. Maybe they're from another country
and they think they're just doing the thing they're supposed
to do. The other thing I want to talk about
(26:44):
in terms of spit, and yes, don't just go spit
it everywhere, because it really is kind of like liquid gold. Um.
I mean, I guess it's very much too like like
we're mentioned in Cornet McCarthy in a recent podcast, read
a Court McCarthy book with a bunch of cowboys in it,
and people just spitting like crazy. Every every line of dialogue,
somebody spits. But every time they do that, these wonderful
enzymes are being released. And unless they're being used for
(27:08):
a purpose, they're just flattering to the ground, then these
enzymes aren't doing any well. Yeah, it's it's a waste
of of of important resources, which is why I like
in the Doune universe among the freeman, i'd like to
to spit. You know, that's a big deal if you're
gonna spit or or weep or something, because you're the
precious liquids you're leaving that well. Yeah, because the saliva
has anti clumping properties and that discourages bacteria from rounding
(27:32):
itself up and adhering to your teeth and gums and
creating colonies. And uh, it also is something that helps
to heal wounds a lot quicker. So you'll see again
in other cultures like for instance, in Greece, you'll see
someone sort of spit on their kids wound or um.
You know, it applies spit in other areas of use,
(27:55):
and that's because of getting these antimicrobial properties that it possesses.
Well you we men, And in a previous episode, I
believe it was the vulture vomit one about the studies
that are going into looking at mothers who choose their food,
human mothers who choose their food for their their their children.
And the idea there is that you're it's the spit,
it's the key to it. Well, yeah, you're the human
(28:15):
blender for them. But also you're coating something that could
be highly allergenic. Um, you're coating those proteins and with
that saliva and you're making less allergenic for the child.
So in a way it's protecting the child as well. Um.
But I wanted to I wanted to leave this area
of this topic by looking at our laundry detergent because
(28:39):
this is a great little tidbit that came up in
the book, and I thought it was great. Mary Roach
had said, Okay, if your saliva has enzymes like amylase,
which breaks down starches to sugars, lip a's which breaks
down fats, and proteas which breaks down protein, that sounds
a lot like what's going on in your laundry and
(29:00):
your laundry detergent. And she did confirm that, in fact,
two of these are actually used in laundry detergent. And
she says that laundry detergent is essentially a digestive tract
in a box. So powerful is that saliva. Wow. I'm
not suggesting everybody just starts spinning into the washing machines now,
but you know, the next time you have a little
(29:21):
stain in your shirt, don't hesitate, you know, rub a
little spin into it. See what happens. All right, Well,
there you go. There is Ah, there's base camp for
the journey through the human body. Um, hopefully we will
we'll come back and continue this journey in future episodes
and uh and take you the rest of the way.
It only gets crazier from here. Alright. So when you
(29:42):
say crazy, I think you mean flatulence. Well, that's gonna
happen eventually, but there's always there's just a whole world.
It's a Lord of the rings Eska journey ahead of
it through the human body. All right, I'm look for it.
All right. Well, on that note, let's call over the
robot and get a little listener mail. All right, So
we are we're currently in As I am reading this,
(30:04):
we have received some emails regarding part one of the
Printer of the Gods episode, the three D Printer of
the Gods episode, but part two has not currently aired yet,
so the the emails that I have that respond to
that just bear in mind that they haven't heard part two.
So first, uh, I want to mention that we uh
we heard from a listener of the name of Lease
(30:25):
Lease Rights in and says, hi, Robert and Julie, just
listen to your three D printing episode. It's interesting stuff,
some of which I really hadn't considered before. The Devon
Tess dress was amazing, and the potential for custom fitting
is very cool. I have a common in particular about
the article on Warhammer miniatures that Robert sided. I haven't
played Warhammer in particular, but I started playing d n D.
That's dungeons and dragons, uh for you novices out there
(30:48):
in the late nineteen seventies. And I worked in a
gaming store in the early to mid nineteen eighties, and
I feel pretty comfortable saying that the article missed the
point about miniatures. Not only have people always painted them,
there's always a long history of altar them, in some
cases resculpting them to amazing degrees um with files and
epoxy and in some cases blowtorches. We're talking about lead
miniatures here, not the resin which games works up uses today. True,
(31:12):
I don't know anyone who built one from scratch, but
there are all sorts of people who have unique miniatures
which don't resemble the base models at all. It's not
merely the game changer you portray it as, at least
in the field of miniature gaming. Likewise, as far as
customizing all sorts of things in the MySpace effect, I
think it's odd to assert that this begins and ends
with three D printing. All sorts of people can and
do customize off the rack clothing, for example, and have
(31:34):
done so for years. They're even people who make their
own clothing from scratch. You might say that three D
printing makes it easier to do that, but even without
ever actually having played with a three D printer cat file,
I'd be willing to bet it still takes skill and
patience and trial and error to get it right. Although
three D printing provides new and interesting materials to play
with and uh, and it may spark a fad in
really individual and funky clothing for a while, I find
(31:56):
it hard to think that it will usher in a
new era of mass individual expread and most of the
masses just don't want to put in that much work.
If they did, they wouldn't have waited for three D
printing to do it. What it will do is provide
a different type of outlet for that really small fraction
of the people who like to make and or customize
their stuff. Cool Well, some interesting thoughts are from from
Lease now. I do want to note that a Warhammer
(32:18):
article that i U I cited they do go into
the customization a little bit, because, certainly with with miniature
gaming today, and you know it's earlier days as well,
you'll have indige individuals who buy the miniature, and the
miniature at the very least comes unassembled and unpainted. So
there are various style choices are gonna come there. Especially
it has multiple parts, uh like likewise, you can then
(32:40):
do various things to it. You can use some uh,
some putty, some uh some various other materials to change
it and make it into the thing you want. Customization,
so that that's uh to our point, that is an
important part of a miniature hobbyists. But all and also
it's again worth noting that yes, we do have the
ability to alter are our products already you can You
(33:02):
can buy clothing off the rack and then alter them
if you have the skill set to do it. But
I still think it's gonna it's gonna change things. But
we'll see how it goes. But most of the sources
I was looking at, maybe they were overselling the idea
in some cases, but I think it really a big
game changers and I think it's it was a good
analogy for for looking at the macro and micro of
its abilities to change the sort of objects we put
(33:23):
out in the world. That's just me talking from my
allergy medicine. There we cool. I also want to mention
we we did receive at least one comment from someone
who wasn't sure exactly where we stood on this whole
exchange of ideas that we see on the Internet, and
we'll be printed. So we brought intellectual property just as
(33:44):
an idea that here's another way in which intellectual property
has not been defined just such a degree that you
might have some people who were taking advantage of it.
Maybe not, We don't know. It's just a question mark. Yeah.
I mean, that's the thing about freedom is that you
freedom gives you the power to create things. It also
has it gives you the ability to u do some
(34:06):
some less advantageous things. And the example I was making
the podcast was that certainly with the Internet now you
can go out and you can steal something that is
somebody's pretty solid intellectual property. And then if we have
with with the age of three D printers, we'll be
able to steal a physical object more or less. So
that was sort of the analogy we were making. But
(34:27):
certainly not every form of sharing on the Internet is
UH is stealing just right, And I think that we're
still at a point where we're trying to figure out
what is stealing, what is sharing, what is fair use
and UH, as we had pointed out thinking the podcast
before oftentimes technologies way ahead of those sort of issues. Anyway, cool,
and then I have just a three quick uh Facebook
(34:49):
comments I wanted to read. This person comes from Meg Mega, says,
listening to the three D Printer podcasts while it work
as a miniature painter for Privateer Press, this is the
first podcast I've listened to it work that's been relevant
to my job. Looking forward to hearing more from you guys.
We also heard from uh from Critter. I don't think
this is Critter Jones, unless Critter Jones has a new
last name, so but maybe we have two listeners name Critter.
(35:12):
Either way, I like that Critter writes and says Hi,
Robert and Julie. I just listened to the interview with
Neil deGrasse Tyson and it blew my mind. I just
love hearing him talk, and so many of the questions
were in the realm of what if Uh, it was
interesting to hear him take them on. He's so intellectually honest.
I thoroughly enjoyed the episode. Please have more scientific guests
on as often as you can. I'd love to hear
(35:33):
you speak with Brian Cox, certainly perhaps about the dark
matter energy issue. And Oliver sacks Allah lepre con hallucinations.
I found them to be fascinating people to hear. Thanks
and keep up the mindful work. Well, thank you very much. Yeah. Actually,
we have an interview with Maria Roach on the books here,
so pretty soon we'll roll that out for you guys,
and we hope that you enjoy it as well. Yeah.
(35:54):
And if yeah, everyone continues to like the interviews and
they perform well, certainly we love talking to uh TO experts,
so we will will try to bring some more on
the podcast and maybe some video stuff as well. And
finally we heard from Chuck and Chuck and responding to
the three D printer says, no, not Josh and Chuck.
It's different, Chuck. There are more Chucks us, just as
(36:15):
there are more critters out there. Chuck says, cool episode, guys,
but please get the firearms terminology right. Unless you were
talking about black powder pistols, all guns are semi automatic.
I think the term you wanted to refer to was
fully automatic. It's a difference between pulling the trigger and
firing one round and pulling the trigger and firing multiple rounds.
That totally was not Chuck Bryant. Yeah, no, actually, thank
(36:38):
you for the distinction. That's really important totally. Uh So,
there you have it. A little listener mail there. We
think you think the robot as always for bringing them
over to us, and if you would like to reach
out to us and share your thoughts on the mouth,
on the tongue, on taste, on how cat's taste haagus um,
anything we talked about in this episode, let us know.
(37:00):
You can find us on Facebook and Tumbler. We are
Stuff to Blow your Mind on both of those. You
can find us on Twitter, where our handles blow the mind,
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dot com, and you can always stop us online at
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(37:26):
this and thousands of other topics, visit how stuff works
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