(singers)
♪ Science ♪
♪ Out loud ♪♪
(man narrating)
We are the most complex
technology on the planet.
Our bodies, honed by thousands
of years of evolution.
Our brains, capable of billions
of calculations per second.
Our position
on the food chain?
The top.
[bobcat snarls]
We are humans.
Bow down before
our physiological majesty.
Hear us...
[sneezes]
Okay, so this might be
our weak point.
Or is it?
Yeah, mucus oozes out of us when
we're sick, but it's also...
One important defense mechanism
our body sets up to protect us.
She would know.
So mucus, which we call snot,
is actually everywhere.
It's human motor oil.
It's in your nose,
on your eyes, in your throat,
lungs, stomach, intestines,
lady parts, dude parts.
The stuff that makes up mucus
is between almost
every single cell in your body,
and you make
a gallon of it every day.
Mucus protects you
in a ton of different ways.
The first way
is by moisturizing.
Mucus is a meshwork
of proteins
with long sugars
branching off of it.
This combo, called mucin,
can bind to and retain
an insane amount of water.
Big deal, right?
It is a big deal.
Without that moisture,
you couldn't eat without
ripping up your esophagus.
Your eyes would dry out,
and your airways,
lungs, and throat
wouldn't trap
and dispose of particles,
which brings up
way number two.
(woman)
Your body constantly
secretes mucus
when your eyes tear up,
or you blow your nose,
or you swallow
your post nasal drip,
or you go to the bathroom.
By trapping
unwanted particles,
this mucus system
is like a car wash
that's flushing out germs
before they can take hold.
This is fake snot made from
corn syrup, gelatin, and water.
It's disgustingly convincing
and would do a decent job
at moisturizing
and protecting
against particles.
But real mucus is loaded
with immune cells
that fight bacteria
and viruses.
And the chemical structure
of mucins keeps bacteria moving
by giving them handholds
to propel themselves on.
If bacteria stop moving,
they could clump together
to form biofilms,
which even the toughest
antibiotics can't always kill.
Researchers are trying to learn
from our own body's
natural defenses
to understand
and fight infections.
In fact, studying mucus
could help us with
many different things--
antibiotic resistance,
cavities in our teeth,
respiratory disease,
even preterm labor.
We're trying to see
if we can use mucus
to predict if a woman is at risk
of delivering a baby too early.
And mucus
doesn't just sit there.
It changes and adapts
to its environment.
Take cervical mucus.
You ladies don't want random
stuff getting in your uterus,
and mucus helps protect
against germs.
But when a woman
wants to have a baby,
mucus lets sperm through.
When she ovulates,
it physically and biologically
changes to let that happen.
And when mucus does let stuff
like good bacteria, or sperm,
or certain particles through,
it doesn't get ripped up
but instead restores its
original mechanical properties
and self-heals,
which is something that
no single man-made material
can do nearly as well
or as easily.
So, see, we are majestic
specimens of life on Earth.
We are humans.
Bow down before us.
Hear us...
[sneezes]
Accessibility provided by the
U.S. Department of Education.
Hi, guys, it's Elizabeth.
Thanks for watching
Science Out Loud.
If you liked it,
subscribe to our channel.
And if you want to
learn more about snot,
go to our website
at k12videos.mit.edu.
Cut.
Uh!
