Latest / Talking Science / The Heart – The Pump That Never Rests

Transcript

The Heart – The Pump That Never Rests · Talking Science

0:00
I want you to do something for me right now.
0:01
Just take a second, wherever you are, and place
0:05
your hand flat against the center of your chest.
0:07
Just right there over the breastbone. Yeah. And
0:10
if you wait a moment, you know, you can feel
0:13
it, that steady rhythmic thump. It's always there.
0:16
Right. And what you are feeling is a muscle that's
0:19
roughly the size of your clenched fist. And it
0:22
has been beating since before you were even born.
0:24
Which is just wild to think about. It really
0:27
is. And if you are like most people, you probably
0:30
have absolutely no idea how much physical force
0:33
that tiny engine is generating just to keep you
0:35
sitting upright right now. Oh, for sure. We completely
0:38
take it for granted. Exactly. So today we are
0:41
doing a deep dive into the mechanics of the human
0:44
heart and the circulatory system. Yes. We are
0:47
tearing down the whole engine today. We're going
0:49
to unpack how this relentless biological machine
0:51
actually keeps you alive. We're going to, you
0:54
know, demystify its architecture. And we're going
0:56
to look at what is literally happening under
0:59
the hood when the plumbing breaks down. It really
1:02
is profound when you stop to actually feel it,
1:05
like you said. I mean, that little muscle hasn't
1:07
taken a single day off. Not one. And the sheer
1:10
scale of the workload it handles is, it's staggering.
1:14
When you run the numbers on this, you are looking
1:16
at a system that executes roughly 100 ,000 beats
1:20
every single day. Okay, let's unpack this. Because
1:24
100 ,000 beats a day, I mean, that means over
1:28
an average lifetime, we were looking at more
1:30
than 2 .5 billion. Two and a half billion without
1:34
stopping. Two and a half billion. And with every
1:37
single one of those flexes, it is generating
1:39
enough pressure to push fluid through a plumbing
1:43
network that is so incredibly vast, it genuinely
1:46
defies logic. It sounds like science fiction.
1:48
Right. If you were to somehow take all of your
1:50
blood vessels out and lay them end to end, they
1:53
would stretch for about 100 ,000 kilometers.
1:55
Yeah. And to put that physical distance in perspective,
1:57
that is enough piping to circle the entire Earth
2:00
twice over. Twice. inside of one person. Cooked
2:03
entirely inside of you. And fluid doesn't just
2:06
move through pipes on its own, you know. It requires
2:09
immense continuous pressure to overcome the friction
2:12
of all those miles of biological tubing. Because
2:14
it has to reach everywhere, right? Exactly. Every
2:16
single cell in your body needs a constant unbroken
2:19
supply of oxygen and nutrients to survive. And
2:23
they are constantly generating waste products
2:25
that need to be carried away. Right. So the heart
2:27
is simply the engine creating that pressure.
2:32
When I was looking at the anatomy of it in our
2:34
sources, I kept thinking about the physics. How
2:36
so? Well, if it's just pushing fluid in a massive
2:40
circle, why is the architecture so complicated?
2:43
I mean, it's not just one big pump sitting in
2:46
the middle of our chest. No, it's not. And this
2:48
raises an important question. Why would one single
2:50
pump not be enough? Right. It comes down to the
2:53
destinations. Right. Blood needs to pick up oxygen
2:55
from your lungs, and then it needs to deliver
2:57
that oxygen to your toes, your brain, your stomach.
3:00
Which are very different distances. Exactly.
3:02
Because those are two entirely different jobs
3:05
requiring two very different amounts of force,
3:07
the heart actually runs two circuits at exactly
3:11
the same time. It's doing two things at once.
3:13
Yes. It is literally two separate pumps fused
3:17
together, sitting side by side, working in tandem.
3:20
See, here's where it gets really interesting
3:22
for me. Because looking at it as two separate
3:25
pumps makes the whole anatomical design suddenly
3:28
make sense. It clears up a lot of the mystery.
3:30
Yeah, because the right side of the heart is
3:33
essentially receiving the blood that is returning
3:35
from the body. This is blood that has already
3:37
dropped off its oxygen to your cells and is now
3:40
carrying a waste product. Carbon dioxide. Precisely.
3:44
The right side takes that oxygen -depleted blood
3:47
and pumps it a very short distance, literally
3:49
just next door to your lungs. Just a quick trip.
3:52
Right. In the lungs, the blood dumps the carbon
3:55
dioxide, which is the gas you exhale, and picks
3:57
up a fresh new load of oxygen from the air you
3:59
just breathed in. I was actually trying to picture
4:02
this division of labor, and I came up with an
4:04
analogy. Oh, let's hear it. So think of the right
4:06
side of your heart like a little local delivery
4:08
van. Okay, I like that. It just does these quick
4:11
short trips back and forth to the local warehouse,
4:14
the lungs to drop off trash and pick up new supplies.
4:17
Yeah. It doesn't need a massive engine for that.
4:20
That's exactly it. It's a low pressure job. But
4:23
then that freshly oxygenated blood travels back
4:26
from the lungs to the heart. And this time it
4:28
enters the left side. And that's a whole different
4:30
ballgame. A vastly different job. It has to take
4:33
that fresh blood and pump it out with enough
4:35
force to push it all the way to your entire body.
4:38
Right. Up against gravity to your brain, all
4:40
the way down to your feet and back again. So
4:42
if the right side is the local delivery van.
4:45
The left side is like a massive long -haul semi
4:48
-truck. Oh, absolutely. It has to drive those
4:51
supplies clear across the country to every distant
4:54
zip code in your body. And that perfectly explains
4:57
the physical structure of the organ. Because
4:59
of the muscle mass. Right. The left side of the
5:01
heart is physically much more muscular and thick
5:04
than the right side. It literally built a much
5:06
bigger engine to push fluid through 100 ,000
5:09
kilometers of pipe. The physical demands on that
5:12
left ventricle, that left lower chamber, are
5:14
immense. And then, you know, the body uses up
5:17
the oxygen that the semi -truck delivers. The
5:20
now depleted blood travels back to the right
5:22
side of the heart, and the whole double loop
5:24
begins again. But if you have this heavy -duty
5:27
semi -truck pushing fluid that hard, how does
5:31
it not just, you know, wash backward the second
5:33
the muscle relaxes? The recoil, yeah. Right,
5:35
like what is the actual mechanical sequence of
5:38
the beat? To understand the beat, you have to
5:40
look at the internal architecture. The heart
5:42
is divided into four rooms, or chambers, two
5:45
on the right pump, two on the left pump. Okay,
5:47
four rooms. And sitting between these chambers
5:49
are sets of one -way doors, which we call valves.
5:52
Valves, right. A heartbeat is simply the highly
5:55
coordinated squeeze of those muscular chambers
5:58
driving the blood forward, combined with those
6:00
doors instantly snapping shut behind the blood.
6:03
So it can't go back. Exactly. To absolutely prevent
6:06
it from sloshing backward into the chamber it
6:08
just left. Wow. So when I hear that classic sound,
6:12
like when a doctor puts a stethoscope to your
6:14
chest and you hear that famous lub -dub, lub
6:17
-dub, I've got my whole life assuming that was
6:20
the acoustic sound of a muscle flexing, like
6:22
a bicep tensing up. And you are not alone. Most
6:24
people assume it's the muscle, but it is purely
6:27
mechanical. Really? Yes. That lub -dub sound
6:31
is the acoustic slam of those one -way valves
6:34
snapping shut in rapid sequence against the fluid.
6:36
That is mind -blowing. Yeah. Lub is the first
6:38
set of doors slamming. Dub is the second set.
6:41
You are quite literally listening to a hydraulic
6:44
machine locking its doors against the backward
6:46
pressure of the blood. So the lub -dub is literally
6:49
just the plumbing system fighting gravity. Basically,
6:51
yes. But muscles don't just flex on their own.
6:54
They need an ignition switch. And this brings
6:57
us to the electrical system, which is, I mean,
6:59
this is where things get... truly bizarre it
7:02
is arguably the most elegant part of the entire
7:04
organ tucked away right inside the muscular wall
7:08
of the right side of the heart is a tiny specialized
7:11
cluster of cells we call it the natural pacemaker
7:14
the natural pacemaker okay its sole biological
7:16
purpose is to spontaneously fire off a tiny electrical
7:20
spark this is on its own yes that spark spreads
7:23
rapidly across the heart muscle and that wave
7:26
of electricity is what commands the chambers
7:29
to contract in exactly the right order at exactly
7:33
the right millisecond. Okay, wait, wait. Let
7:34
me push back on this for a second just to make
7:36
sure I am grasping the implications here. Are
7:39
you saying my brain isn't actively telling my
7:41
heart to beat right now? What's fascinating here
7:44
is exactly that. Your heart does not wait for
7:47
conscious or even unconscious instructions from
7:50
your brain to initiate a physical beat. That
7:52
is wild. It sets its own autonomous pace. Now,
7:55
your brain and your nervous system can send chemical
7:57
signals to the pacemaker to say, hey, we are
8:00
running for our lives. Speed the assembly line
8:02
up. Or, you know, we're sleeping. Right. We are
8:04
deep in sleep. Slow things down. But the fundamental
8:08
spark, the actual ignition of the engine, is
8:11
generated by the heart itself, completely independent
8:14
of the brain. That explains so much about medical
8:16
emergencies. Like that is why if you've ever
8:19
seen footage or read about transplant surgeries,
8:22
a human heart can literally be removed from a
8:25
body and for a brief time just keep right on
8:28
beating in a tray as long as it has oxygen. Exactly.
8:30
Because it's providing its own spark plug. It
8:32
has its own isolated power grid. Yeah. And understanding
8:35
that grid is exactly... exactly how medical technology
8:38
was able to invent artificial pacemakers. Oh,
8:40
of course. Yeah. If that tiny natural cluster
8:43
of cells, that ignition switch, starts to falter,
8:45
or if the wiring gets frayed as we age, a surgeon
8:49
can implant a small artificial battery that simply
8:51
takes over the job. It just mimics the spark.
8:53
Precisely. It sends that exact same regular autonomous
8:57
electrical spark into the muscle to keep the
8:59
rhythm going perfectly. So we have this brilliant
9:02
autonomous electrical grid. setting the pace,
9:05
and these mechanical doors snapping shut to push
9:08
the fluid forward. But let's look at the cargo
9:10
that is actually moving along these highways.
9:13
The blood itself. Yeah, because we talk about
9:14
blood like it's just a simple red liquid, right?
9:16
Like water with food coloring in it. Well, it
9:19
is far more complex than that. Blood is actually
9:21
a living tissue. A tissue. Yes. And it has several
9:26
highly distinct jobs happening simultaneously.
9:29
To start with... All of this living cellular
9:31
cargo is suspended and carried in a straw -colored
9:34
fluid called plasma. Plasma, okay. If you were
9:37
to put a vial of blood in a centrifuge and spin
9:40
all the heavy cells down to the bottom, you'd
9:42
be left with this yellowish, watery liquid on
9:44
top. That plasma is the river itself. And floating
9:48
in that river, you have the cargo ships, the
9:50
most famous, of course, being the red blood cells.
9:53
The red blood cells are the dedicated oxygen
9:55
ferries. They are packed with a highly specialized
9:57
iron -rich protein called hemoglobin. Hemoglobin,
10:00
right. I remember that from science class. As
10:02
they pass through the lungs, that hemoglobin
10:05
binds tightly to oxygen molecules. That iron
10:08
-rich protein binding with oxygen is exactly
10:11
what turns the blood that bright, deep red color.
10:14
That makes perfect sense. And riding right alongside
10:16
them in the plasma, you have the white blood
10:19
cells, which are essentially the internal security
10:22
apparatus. Yes, the immune defenders. Right.
10:24
They are a core part of your immune system, constantly
10:28
patrolling the bloodstream, looking for invading
10:30
bacteria, viruses, or even abnormal cells to
10:33
attack and dismantle. And finally, you have the
10:35
platelets. Ah, the platelets. These aren't even
10:38
full cells, actually. They are tiny, specialized
10:41
fragments of cells. Their job is to act as the
10:45
emergency structural repair crew. How does that
10:47
work? If a blood vessel gets damaged, cut, or
10:50
torn, structural proteins in the pipe wall are
10:53
suddenly exposed to the flowing blood. The platelets
10:56
instantly detect those proteins, rush to the
10:58
site, stick to the walls and to each other, and
11:01
form a physical plug, a clot, to stop the leak
11:04
before you bleed out. That's incredible. So you
11:06
have the river of plasma, the red oxygen cargo
11:09
ships, the white security guards, and the platelet
11:13
repair crews. And they are all traveling on a
11:16
very specific set of roads. They sure are. The
11:20
plumbing itself is divided into three main types
11:22
of vessels, right? Yes, and their structures
11:25
are dictated entirely by physics. The first are
11:28
the arteries. Okay, arteries. Arteries always
11:30
carry blood away from the heart. Because they
11:33
are taking the direct high pressure physical
11:35
blast from that heavy duty left pump we talked
11:38
about, arteries have to be built tough. They
11:40
need to handle the semi -truck pressure. Exactly.
11:42
They have thick, highly muscular elastic walls
11:45
that expand and contract to handle the sheer
11:48
force of the fluid hitting them. Which brings
11:51
up a term everyone listening has heard a thousand
11:53
times blood pressure. Oh, yes. When a doctor
11:56
wraps that cuff around your arm and pumps it
11:58
up, they aren't just taking like an abstract
12:01
health reading. They are literally measuring
12:03
the physical tension inside your own pipes in
12:05
that exact moment. That is literally what they're
12:07
doing. They are measuring the sheer physical
12:10
force of the blood pushing outward against those
12:13
thick artery walls as the heart pumps. That is
12:16
exactly what that number is. It's a measure of
12:18
the tension in the system. So the arteries carry
12:21
the high -pressure blood away. But as they get
12:23
further from the heart, they branch out getting
12:25
smaller and smaller until they turn into the
12:28
second type of vessel capillaries. The capillaries
12:31
are, honestly, they're my favorite detail in
12:34
all of this. They are pretty amazing. These vessels
12:36
are so incredibly fine, so microscopic, that
12:40
the blood cells actually have to pass through
12:42
them in single file. Like a tunnel. Yeah. I was
12:44
visualizing it like a massive national road network.
12:47
The arteries coming off the heart are like massive
12:49
high -speed concrete multi -lane highways. Sure.
12:52
But eventually those highways have to take exits
12:54
into towns, then neighborhoods, and finally down
12:57
to tiny single -lane dirt roads, the capillaries.
13:01
I love that analogy. And it's on those microscopic
13:03
single -lane dirt roads that the actual hand
13:07
-to -hand delivery of oxygen and nutrients to
13:09
your individual muscle and organ cells takes
13:11
place. It's the perfect visual because the capillaries
13:14
have incredibly thin walls, often just one cell
13:17
thick, specifically so that oxygen and nutrients
13:21
can easily slip through the wall into the surrounding
13:24
tissue and carbon dioxide can slip back in. Just
13:27
a quick swap. Right. Once that molecular exchange
13:30
happens, those tiny capillaries merge back together.
13:33
They get wider and wider, turning into the third
13:37
type of vessel veins. And veins are the return
13:39
trip. Exactly. Veins are the low pressure return
13:43
pipes that bring the now depleted blood back
13:46
to the right side of the heart, the local delivery
13:48
van, to start the whole massive process over
13:50
again. So understanding this high pressure plumbing
13:53
network, and especially those sticky little repair
13:55
platelets that form clots, is critical when we
13:59
look at why this system breaks down. This is
14:01
the really important part. Yeah, because when
14:02
we talk about cardiovascular disease, we are
14:04
talking about the world's leading cause of death.
14:06
But I feel like most people... Deeply, let's
14:08
understand what is actually failing. How do you
14:11
mean? Well, we usually think of a heart attack
14:13
as the engine itself just giving out, like a
14:15
motor blowing a gasket. And that is the most
14:18
common misconception. It is almost never a problem
14:21
with the motor itself. It is a problem with the
14:23
plumbing. The plumbing, okay. Here is the mechanism
14:26
the heart muscle is working constantly. It never
14:29
rests, which means the heart itself needs a massive,
14:32
continuous supply of its own oxygenated blood.
14:36
Right. It can't just run on fumes. Exactly. And
14:38
it doesn't just absorb oxygen from the blood
14:40
sloshing around inside its internal chambers.
14:43
It relies on its own private, dedicated set of
14:46
arteries called coronary arteries, which wrap
14:49
around the outside surface of the heart like
14:51
a crown. So the engine needs its own fuel lines
14:53
to keep pumping fuel to everything else. Precisely.
14:56
Now, over many years or decades, those vital
15:00
coronary fuel lines can slowly start to narrow.
15:03
From what? Fatty deposits, cholesterol, and cellular
15:06
waste, which we collectively call plaques, gradually
15:08
build up inside the inner walls of those specific
15:11
arteries. Just kind of lining the pipes? Right.
15:13
This slow, decades -long buildup process is a
15:16
condition known as atherosclerosis. So we have
15:19
this gunk slowly turning a wide pipe into a very
15:22
narrow pipe. But a heart attack is sudden. It
15:25
happens in minutes. So the slow narrowing isn't
15:29
what instantly kills you. No, the narrowing just
15:31
sets the stage for the catastrophe. Okay, so
15:33
what actually triggers it? What happens is that
15:36
the surface of one of these fatty plaques on
15:38
the artery wall suddenly tears or ruptures. And
15:42
when that inner lining tears, remember those
15:44
platelets we talked about? The emergency repair
15:46
crew? Oh, wow. Wait, the body senses the ruptured
15:50
plaque as a damaged blood vessel? It thinks it's
15:52
springing a leak. Yes. you got it that is tragic
15:56
it really is The platelets detect the exposed
15:59
proteins from the tear, and they instantly rush
16:01
in to fix it. They do their evolutionary job
16:03
perfectly. They clump together and form a rapid
16:06
blood clot over the rupture. But the bite was
16:09
already narrow. Exactly. Because the artery was
16:11
already severely narrowed by the plaque buildup,
16:14
that sudden structural clot entirely blocks whatever
16:17
small opening was left in the pipe. It just clugs
16:19
it completely. Suddenly, in a matter of seconds,
16:22
absolutely zero blood can flow past that point.
16:25
So what does this all mean? It means the repair
16:27
crew actually causes the final blockage. Sadly,
16:30
yes. And the patch of heart muscle downstream
16:33
of that blocked pipe is instantly starved of
16:36
oxygen. It is suffocating. It is suffocating.
16:40
And if that physical clot isn't cleared by emergency
16:43
doctors very, very quickly, that specific section
16:46
of the heart muscle begins to permanently die.
16:49
That is terrifying. And that is the literal definition
16:52
of a heart attack. It is not the heart simply
16:55
stopping out of nowhere. An electrical failure
16:57
where the heart just stops beating is called
16:59
cardiac arrest. Oh, I see. Yeah. A heart attack
17:02
is a plumbing blockage that cuts off the heart's
17:04
own personal supply lines, suffocating a section
17:07
of the muscle while it... desperately tries to
17:09
keep working. And it's worth noting that a stroke
17:11
is basically the exact same mechanical plumbing
17:14
failure, right? A ruptured plaque and a sudden
17:16
clot, yes. But the blocked pipe happens to be
17:19
feeding a section of the brain instead of the
17:22
heart. Correct. It is the exact same underlying
17:24
disease process, just striking a different destination
17:27
in the highway network. Man, I know that talking
17:31
about ruptured plaques and suffocation strokes
17:33
sounds... It's terrifying. It can be very scary
17:37
to think about. It feels like we are all just
17:40
walking around with these fragile time bombs
17:42
in our chests. But looking at it as a mechanical
17:46
plumbing issue completely changed how I think
17:49
about maintenance. It actually makes it incredibly
17:51
empowering. If we connect this... To the bigger
17:55
picture, empowerment is exactly what this knowledge
17:57
provides. Because we can do something about it.
18:00
Absolutely. It is true that some of your risk
18:03
for cardiovascular disease comes down to age
18:05
and genetics. You can't control who your parents
18:07
are and you can't stop the clock. Right. But
18:10
a massive proportion of your risk is dictated
18:13
by mechanical factors you completely control.
18:15
We're talking about the major lifestyle factors.
18:17
High blood pressure, smoking, physical inactivity,
18:19
poor diet. The classics. Yeah. When you just
18:22
hear a doctor list those off, they sound like
18:23
generic wellness tips. But when you understand
18:26
the mechanics, you realize they're physical maintenance
18:28
steps for the pipes. It's pure engineering. Right.
18:31
Take smoking, for example. How does inhaling
18:34
smoke actually cause a heart attack in a chest
18:37
pipe? It is entirely chemical and mechanical.
18:40
Okay. The thousands of toxic chemicals in cigarette
18:42
smoke enter your bloodstream and physically scar
18:45
the delicate, slippery inner lining of your blood
18:48
vessels. They damage the walls? Yes. They essentially
18:51
create microscopic potholes and rough patches
18:54
along the walls. Those rough patches are exactly
18:57
where circulating cholesterol gets caught and
18:59
begins to build those deadly plaques. Smoking...
19:03
destroys the Teflon coating of your highways.
19:05
So quitting smoking isn't just about your lungs.
19:07
It's stopping the active destruction of your
19:10
plumbing's nonstick surface. Beautifully put.
19:13
And what about exercise? Why does going for a
19:15
jog protect the heart? Because it forces the
19:18
system to adapt. When you exercise, your heart
19:20
pumps harder and your blood vessels are forced
19:23
to dilate to widen to accommodate the increased
19:26
blood flow. It's like a workout for the pipes
19:27
themselves. Doing this regularly keeps the muscular
19:30
walls of your arteries flexible, elastic, and
19:32
strong. If you are entirely inactive, the vessels
19:35
become stiff and rigid. And I'm guessing rigid
19:38
pipes aren't good. No, rigid pipes under pressure
19:41
are far more likely to sustain the micro tears
19:44
that lead to plaque buildup. Which ties perfectly
19:46
into blood pressure. If you have chronic high
19:49
blood pressure, it's like running a garden hose
19:51
at maximum blast 24 hours a day, seven days a
19:54
week. It's so much unnecessary wear and tear.
19:57
Eventually, the rubber is going to get stressed.
19:59
fray and sustained damage. Yeah. Managing your
20:01
blood pressure through diet like you know watching
20:04
your sodium intake or through medication is literally
20:07
just turning the faucet down so the pipes don't
20:09
blow out. Exactly. And a balanced diet simply
20:12
manages the amount of raw material like LDL cholesterol
20:15
that is floating around in the plasma looking
20:18
for a pothole to get stuck in. All connected.
20:20
The evidence in the medical community is overwhelming
20:23
moving your body not smoking. eating reasonably,
20:27
and managing your blood pressure genuinely, measurably
20:30
protects this mechanical system. It honestly
20:33
asks for very little in return for beating 100
20:36
,000 times a day without complaint. It really
20:38
doesn't ask for much. It's doing the most vital
20:41
job in your entire body. And all it really asks
20:43
is that we take it for a walk to keep the pikes
20:46
flexible and eat a vegetable now and then so
20:48
we don't clog the fuel lines. When you view it
20:50
as a machine, it's a very fair trade. It really
20:53
is. So just to wrap up our journey today, we've
20:56
zoomed in on this fist -sized double pump engine.
20:59
We've seen how the right side acts as the local
21:02
van feeding the lungs, while the left side is
21:05
a semi -druck powering the entire body. A brilliant
21:08
division of labor. We explored its autonomous
21:11
electrical grid that sparks every single beat
21:14
without waiting for the brain's permission. We
21:17
rode along a 100 ,000 -kilometer network of muscular
21:20
highways and microscopic dirt roads, carrying
21:23
a living cellular cargo. It's quite a trip. And
21:26
most importantly, we've seen how keeping those
21:27
pipes flexible and clear of plaques is the ultimate
21:30
key to maintaining the whole incredible system.
21:33
And as we sign off, I want to leave you with
21:34
one final thought to mull over, building on what
21:36
we discussed about that natural pacemaker. Oh,
21:39
I like this. We talked about how the heart has
21:41
its own independent electrical system, right?
21:44
It sets its own pace. It doesn't wait for the
21:46
brain to initiate the beat. Right, the autonomous
21:49
spark. Which raises an absolutely fascinating
21:51
question about the human experience. When you
21:55
feel sudden gripping anxiety or a massive rush
21:59
of excitement or a moment of deep, profound calm,
22:02
we usually assume those emotions originate entirely
22:05
in our minds and our body just reacts. Sure.
22:07
Brain first, body second. But if this little
22:10
engine in your chest is autonomously adjusting
22:12
its pace to the physical chemistry of your body,
22:15
independent of your brain's direct control, how
22:18
much of what we consider to be our emotions is
22:20
actually just our brain reacting to the autonomous
22:22
speeding up or slowing down of that little electrical
22:25
spark in our chest. Oh, wow. Are we feeling our
22:28
thoughts or are we simply feeling our pump? Wow.
22:30
Are we feeling our thoughts or are we feeling
22:32
our pump? I am going to be thinking about the
22:34
direction of that feedback loop all day. Thank
22:37
you for joining us on this deep dive. The next
22:39
time you happen to feel your pulse, maybe spare
22:41
a quick thought of gratitude for the hardest
22:43
working muscle you own. See you next time.