If we just hung out here in silence for a second…
Yep, we’re both still breathing.
Whew.
It has a lot of names: hypoxic drive, respiration, breathing…
needless to say, you know what it is.
It’s this.
But have you ever thought about it?
I mean not in the way that you’re thinking about breathing now.
HA.
Deal with that.
But have you thought about how your body does this when you’re asleep, when you’re distracted
or really focused.
No matter what you’re doing (for the most part) your body is breathing for you.
That drive to breathe is strong.
The reason you can do it without thinking is because your brainstem is doing the work
and making the decisions.
But we’ll come back to that in a sec.
Breathing is a really complex balance of pulling oxygen in from the environment, and getting
carbon dioxide out of your blood.
Even though we need oxygen to survive, the main influencer of the drive to breathe isn’t
oxygen, but CO2 -- or really, CO2’s tendency to dissolve into water.
Out in the world, carbon dioxide binds with H2O to create carbonic acid… it’s why
a glass of water left overnight tastes funny.
It’s gots CO2 in it.
The more CO2 there is in your blood, the more acidic it is.
The brain doesn’t like blood that’s too acidic or too basic, so it needs to monitor
it constantly.
That’s why, spread throughout all this are chemoreceptors … central chemorteceptors
are in your brain … peripheral chemoreceptors are in the body’s blood vessels.
Those receptors sense subtle shifts in the levels of carbon dioxide and the acidity of
your blood, and send that info to the respiratory centers in the medulla of your brain stem.
Based on the acidity readings from those chemoreceptors, your brain directs your lungs to make little
adjustments in your rate of breathing to try and keep your CO2 levels as steady as possible.
It happens all the time.
Now you’re thinking about your breathing again.
HA!
Here’s the fun part.
If you’re say, HYPOventilating, HYPER in medical context makes sense -- it’s FAST.
HYPO is the opposite.
Slow…
So you’re HYPOventilating…
When that happens, the CO2 level goes up, and your brain wants to get rid of it!
So, it drives you to breathe more.
That’s called the hypercapnic drive to breathe…
HYPO - HYPER.
Thus if you’re HYPERventilating, then your carbon dioxide level goes down… that’s
called HYPOcapnia… the drive to breathe goes down as well.
This all makes sense.
And yet, we wouldn’t be humans if we didn’t see something working beautifully and say,
“Hold my beer.”
The hypoxic drive is part of the autonomic nervous system -- pupil dilation, heartbeat,
breathing, digestion -- all that stuff.
It’s like the Morlocks of the civilization that is your body.
Nerd reference.
Anyway.
Sometimes people try to trick their brains and create a state of HYPOcapnia -- low CO2,
remember? -- by hyperventilating on purpose.
I’m talking about Freedivers.
To hold their breath for a long time, some freedivers will hyperventilate before ducking
into the water.
They can stay underwater longer BUT!!
BIG B-U-T.
This hypocapnic state can cause a phenomenon called “ascent blackout” which is deadly.
Basically, the hyperventilation makes you get rid of more carbon dioxide, making you
want to breathe slower.
But, while underwater, you’re not replacing O2, for obvious reasons.
Remember, your brain isn’t as driven by the need for O2 as it is driven by clearing
CO2.
So, after a bit with low CO2 levels and decreasing O2 levels, the diver runs out of oxygen to
burn, and passes out.
All without the brain ever triggering the sympathetic nervous system to kick in and
breathe.
Instead, the diver has to surface and intentionally take a breath in time.
This is super dangerous.
DON’T DO IT.
SERIOUSLY.
Don’t.
This can even happen in shallow water…
it’s called shallow water blackout.
And people die.
Of course, even though CO2 is the driver, oxygen still matters!
The brain does monitor oxygen levels.
If they drop really low, the body will kick that drive to breathe again.
But this matters more at high altitudes where there’s less air -- that’s a whole other
thing.
Look, the bottom line here is -- when you’re not thinking about breathing your body is
doing LOTS OF THINGS to keep you alive.
Respiration is a base function of a living thing.
So, we’re really good at doing this even when we’re distracted by our phones, or
are driving, or sleeping!
The body is such a cool machine.
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The body doesn’t just need oxygen -- we also need food; and if you’re going to eat,
you may as well learn too!
Our friends at Thrillist just launched their brand new show Food/Groups!
My buddy Dave Infante is going to talk to food experts as they hunt down a dish that’s
authentically tied to a different neighborhood, nationality, or lifestyle.
Check out an episode here if you love food and love learning about humans, cultures and
awesomeness!
Are you still thinking about breathing?
How many times did you think about it during this episode?
Tell us down in the comments and make sure you subscribe for more seeker, thanks for
watching.