Would you like to inspect the original subtitles? These are the user uploaded subtitles that are being translated:
1
00:00:00,000 --> 00:00:16,060
Think about it.
2
00:00:16,060 --> 00:00:24,940
When you're sitting still and not breathing, what is the only thing in your body that's
3
00:00:24,940 --> 00:00:29,140
palpably moving?
4
00:00:29,140 --> 00:00:44,840
Every second, your body gives you a little sign to prove that it's still there, a pulse.
5
00:00:44,840 --> 00:00:57,100
It is billions of cells beating for billions of times in a lifetime, never pausing to rest.
6
00:00:57,100 --> 00:01:06,640
Behind that beat is an unbelievably vast system whose one and only job is to make sure every
7
00:01:06,640 --> 00:01:16,020
cell in your body stays alive.
8
00:01:16,020 --> 00:01:26,500
The speed, the strength, the frequency, the rhythm.
9
00:01:26,500 --> 00:01:29,060
It tells us so much.
10
00:01:29,060 --> 00:01:39,580
A heart that thumps, blood that flows through thousands of miles of arteries and veins.
11
00:01:39,580 --> 00:01:45,940
Also we can attempt the crazy feats that make humans unique.
12
00:02:09,580 --> 00:02:24,920
Human life depends on one substance above all others, oxygen.
13
00:02:24,920 --> 00:02:31,860
We can go about three weeks without food, three days without water.
14
00:02:31,860 --> 00:02:38,340
But without oxygen, we wouldn't last three minutes.
15
00:02:38,340 --> 00:02:39,980
But why?
16
00:02:39,980 --> 00:02:46,140
Well, if you think about it, each of us is just a huge pile of cells, somewhere around
17
00:02:46,140 --> 00:02:49,140
37 trillion.
18
00:02:49,140 --> 00:02:56,200
Blood cells, skin cells, brain cells.
19
00:02:56,200 --> 00:03:04,420
And every single one of those cells contains an engine that runs on oxygen.
20
00:03:04,420 --> 00:03:08,260
Think of it like a fire that's always burning.
21
00:03:08,260 --> 00:03:13,460
One is the wood or coal.
22
00:03:13,460 --> 00:03:17,900
And to keep the fire stoked, all we have to do is breathe in.
23
00:03:17,900 --> 00:03:23,780
But getting a supply of oxygen is actually the easy part.
24
00:03:23,780 --> 00:03:30,620
Once it's inside the body, all that fuel has to somehow find its way into those 37 trillion
25
00:03:30,620 --> 00:03:33,260
engines.
26
00:03:33,260 --> 00:03:38,140
And that requires a system that never rests.
27
00:03:38,140 --> 00:03:46,380
The cardiovascular and circulatory system represent our major engine in our bodies.
28
00:03:46,380 --> 00:03:53,300
Now this system makes sure that all of our cells have oxygen going in, carbon dioxide
29
00:03:53,300 --> 00:04:03,900
leaving, plenty of nutrients, and essentially keeps us going.
30
00:04:03,900 --> 00:04:11,460
The body itself is pretty small, but the network of vessels is enormous.
31
00:04:11,460 --> 00:04:18,700
The vessels themselves laid end to end would be about 100,000 miles long, which would encircle
32
00:04:18,700 --> 00:04:21,340
the globe probably four times.
33
00:04:21,340 --> 00:04:29,060
This vast network of pumps, valves, and tunnels delivers oxygen to cells in every corner of
34
00:04:29,060 --> 00:04:33,940
your body without you ever having to think about it.
35
00:04:33,940 --> 00:04:41,700
And what's more insane than that is we can train that system to work even more efficiently,
36
00:04:41,700 --> 00:04:58,540
especially when oxygen is harder to come by.
37
00:04:58,540 --> 00:05:06,700
It would be difficult to sum me up in one word because I'm a bit of a contradiction.
38
00:05:06,700 --> 00:05:15,420
On one hand, I'm a Southern belle, a debutante, and afraid of heights.
39
00:05:15,420 --> 00:05:27,860
But I'm also an extreme alpinist, an ice climber, and a rock climber.
40
00:05:27,860 --> 00:05:30,220
My name is Kitty Calhoun.
41
00:05:30,220 --> 00:05:34,380
Ice climbing is who I am.
42
00:05:34,380 --> 00:05:42,060
High altitude ice climbing is the ultimate test for the cardiovascular system.
43
00:05:42,060 --> 00:05:48,660
Imagine you're scaling a vertical slab of ice.
44
00:05:48,660 --> 00:05:55,820
Your body is screaming for oxygen to feed your muscles, to keep moving upwards.
45
00:05:55,820 --> 00:06:03,140
It's true that any elite athlete has to have an extremely efficient cardiovascular system.
46
00:06:03,140 --> 00:06:06,500
But climbing is different.
47
00:06:06,500 --> 00:06:13,220
The air at high altitudes is depleted of oxygen, and freezing temperatures tax a system that's
48
00:06:13,220 --> 00:06:20,660
already pushed to the brink.
49
00:06:20,660 --> 00:06:30,460
Then add in one last factor, the heart-pounding knowledge that at any moment, you could slip.
50
00:06:30,460 --> 00:06:34,700
Training to climb means teaching the body to adapt to an atmosphere that can barely
51
00:06:34,700 --> 00:06:38,980
sustain human life.
52
00:06:38,980 --> 00:06:48,060
And that training begins in one place, the heart.
53
00:06:48,060 --> 00:06:57,940
The heart is the first organ to start functioning, and is typically the last one to stop functioning
54
00:06:57,940 --> 00:07:01,700
in a human lifetime.
55
00:07:01,700 --> 00:07:08,540
It's only the size of a fist, but it beats more than 100,000 times a day.
56
00:07:08,540 --> 00:07:12,940
The heart itself is just two pumps, side by side.
57
00:07:12,940 --> 00:07:18,180
On the left, the tricuspid valve collects blood from all over the body.
58
00:07:18,180 --> 00:07:23,140
On the right, the pulmonary valve takes that blood and shoots it into the organ that surrounds
59
00:07:23,140 --> 00:07:30,180
the heart, the lungs.
60
00:07:30,180 --> 00:07:38,980
There, the blood picks up oxygen from tiny air-filled sacs called alveoli that expand
61
00:07:38,980 --> 00:07:45,260
like balloons every time we inhale.
62
00:07:45,260 --> 00:07:50,140
Then it goes back to the heart so that all that oxygen-rich blood can get pumped to the
63
00:07:50,140 --> 00:07:52,980
rest of the body.
64
00:07:52,980 --> 00:07:58,700
After a minute, it returns, ready for another trip.
65
00:07:58,700 --> 00:08:03,540
That cycle happens every second of every day.
66
00:08:03,540 --> 00:08:17,980
But throw a mountain into the mix, and things get interesting.
67
00:08:17,980 --> 00:08:23,020
Ice climbing is an activity where you have to be in good cardio shape.
68
00:08:23,020 --> 00:08:29,660
When I'm not ice climbing, I'm getting a good cardio working in a short amount of time.
69
00:08:29,660 --> 00:08:34,060
In order for Kitty's heart to perform well on the ice, she needs to train it to pump
70
00:08:34,060 --> 00:08:39,300
blood as dynamically as possible.
71
00:08:39,300 --> 00:08:45,740
During exercise, there are a lot of changes that occur in our cardiovascular system.
72
00:08:45,740 --> 00:08:48,600
The heart obviously speeds up.
73
00:08:48,600 --> 00:08:54,540
The more beats per minute, the more blood flow out of the heart per minute, and therefore
74
00:08:54,540 --> 00:09:00,060
the more oxygen delivery to the tissues.
75
00:09:00,060 --> 00:09:11,260
The efficiency of oxygen transfer also increases so that muscles can use the oxygen more efficiently.
76
00:09:11,260 --> 00:09:18,300
Consistently exercising the heart muscle trains it to push more blood out with each beat,
77
00:09:18,300 --> 00:09:23,440
which means it doesn't need to beat as often.
78
00:09:23,440 --> 00:09:30,120
The human heart is, like any other part of our biology, highly adaptive.
79
00:09:30,120 --> 00:09:35,480
The more demands that are placed on our heart, the more the heart responds in terms of its
80
00:09:35,480 --> 00:09:36,480
capacity.
81
00:09:36,480 --> 00:09:43,140
Over time, we'll find the resting heart rate of a marathon runner will be much lower than
82
00:09:43,140 --> 00:09:50,060
that of a person who is much more sedentary.
83
00:09:50,220 --> 00:09:55,020
Kitty has trained her heart to withstand the physical stresses of a climb up a solid sheet
84
00:09:55,020 --> 00:09:57,360
of ice.
85
00:09:57,360 --> 00:10:03,280
But in this sport, there's more than just exhaustion at stake.
86
00:10:03,280 --> 00:10:08,260
If you're hanging by an axe from a cliff, your heart is also being challenged by something
87
00:10:08,260 --> 00:10:12,100
else — fear.
88
00:10:12,100 --> 00:10:14,660
You know, there's risk in life, right?
89
00:10:14,660 --> 00:10:18,480
If you don't step out the door, then you won't get hit by a car.
90
00:10:18,500 --> 00:10:25,280
If you don't go ice-climbing, then you won't have an accident ice-climbing.
91
00:10:25,280 --> 00:10:29,920
Risk is something that people try to shut out in their lives.
92
00:10:29,920 --> 00:10:35,200
And I think to live life fully, to experience all that life has to give, that what you have
93
00:10:35,200 --> 00:10:40,360
to do is minimize the risk by getting experience and making good decisions.
94
00:10:48,480 --> 00:11:02,680
I do feel fear standing down at the bottom and looking up at the climb.
95
00:11:02,680 --> 00:11:06,880
I still have a healthy fear of falling.
96
00:11:06,880 --> 00:11:13,360
So one of the biggest tricks that I use to keep it together mentally is breathing.
97
00:11:19,360 --> 00:11:25,960
When the system runs amok, like in a panic attack, the heart speeds up, the heart pumps
98
00:11:25,960 --> 00:11:33,020
less efficiently and is less able to meet the metabolic demands of the body.
99
00:11:33,020 --> 00:11:40,860
So an ice climber, for example, would have to get control of that response to slow down
100
00:11:40,860 --> 00:11:52,100
her heartbeat and enable the heart to fill properly and pump blood more efficiently.
101
00:11:52,100 --> 00:11:56,620
Climbing is as much mental as it is physical.
102
00:11:56,620 --> 00:12:01,540
As Kitty's heart has transformed over time to be able to handle the extreme conditions,
103
00:12:01,540 --> 00:12:05,140
so has her brain.
104
00:12:05,140 --> 00:12:10,960
I start climbing and I'm focused on breathing and making sure that I work my feet up high
105
00:12:10,960 --> 00:12:16,760
and then push up off my legs like you're doing a squat.
106
00:12:16,760 --> 00:12:23,820
When you do pull with your arms, you really try to use your back as much as you can.
107
00:12:23,820 --> 00:12:26,460
Everything is a balance.
108
00:12:26,460 --> 00:12:30,660
It's all a highly coordinated dance.
109
00:12:30,660 --> 00:12:36,380
The mind keeps everything in check while muscles all over the body reach their limit
110
00:12:36,380 --> 00:12:41,780
in constant need of more oxygen.
111
00:12:41,780 --> 00:12:48,620
Kitty's well-trained heart handles all these tasks easily.
112
00:12:48,620 --> 00:12:55,900
The hard part is getting the supply of oxygen in the first place.
113
00:12:55,900 --> 00:13:01,620
At high altitudes, the atmosphere contains a lot less oxygen.
114
00:13:01,620 --> 00:13:05,820
That means there's less fuel for red blood cells to extract from the air entering the
115
00:13:05,820 --> 00:13:07,820
lungs.
116
00:13:07,820 --> 00:13:12,580
If you've ever been up that high, you know how heavy your breathing gets.
117
00:13:12,580 --> 00:13:21,220
To try and compensate, the heart goes into overdrive to pump blood to starving muscles.
118
00:13:21,220 --> 00:13:26,220
The low levels of oxygen in the blood can cause headaches and fatigue as the body tries
119
00:13:26,220 --> 00:13:29,020
to function with less fuel.
120
00:13:29,020 --> 00:13:36,740
It can also affect the mind.
121
00:13:36,740 --> 00:13:40,900
Every organ depends on the heart for its function.
122
00:13:40,900 --> 00:13:46,680
The brain cannot function without a moving heart.
123
00:13:46,680 --> 00:13:50,420
Without oxygen, the brain gets foggy.
124
00:13:50,420 --> 00:13:54,740
That's another reason spending too much time up in the clouds is dangerous.
125
00:13:54,740 --> 00:14:04,180
Your judgment goes right out the window.
126
00:14:04,180 --> 00:14:07,620
But once again, Kitty's body is different.
127
00:14:07,620 --> 00:14:12,740
Her red blood cells are better at adjusting to the changing atmosphere, which gives her
128
00:14:12,840 --> 00:14:15,000
the edge she needs to get to the top.
129
00:14:15,000 --> 00:14:20,000
Whoo, yay.
130
00:14:20,000 --> 00:14:27,000
Oh man, feels good.
131
00:14:27,000 --> 00:14:41,800
When I'm at the top, I feel a sense of relief for sure.
132
00:14:41,860 --> 00:14:45,860
A sense of accomplishment.
133
00:14:45,860 --> 00:14:51,660
Climbing is a form of therapy for me because I can just escape.
134
00:14:51,660 --> 00:14:53,180
And I enjoy breathing hard.
135
00:14:53,180 --> 00:14:56,340
I enjoy the strength aspect of it.
136
00:14:56,340 --> 00:15:11,900
I enjoy just moving in a different way.
137
00:15:11,900 --> 00:15:25,420
This frozen ice face melts when the seasons change, leading streams into rivers.
138
00:15:25,420 --> 00:15:32,820
Humans snake through the landscape and bring life.
139
00:15:32,820 --> 00:15:38,220
Humans use these waterways for transport and trade.
140
00:15:38,220 --> 00:15:41,920
We construct cities around them.
141
00:15:41,920 --> 00:15:46,060
They hold spiritual meaning for us.
142
00:15:46,060 --> 00:15:52,000
The constant flow of water through rivers has supported life for millennia.
143
00:15:52,000 --> 00:16:01,840
Much like the labyrinth intertwined right underneath our skin.
144
00:16:01,840 --> 00:16:09,500
Because our blood has to be conveyed to every cell in the body, the enormity of the blood
145
00:16:09,500 --> 00:16:14,840
vessels in our body is really mind boggling.
146
00:16:14,840 --> 00:16:20,600
A lot of simpler life forms don't need a circulatory system because they're just one-cell beings
147
00:16:20,600 --> 00:16:26,920
and they can rely on the diffusion of molecules within their one cell to carry everything
148
00:16:26,920 --> 00:16:28,800
around that they need to.
149
00:16:28,800 --> 00:16:38,360
But we as humans are made up of many cells and we needed to evolve a system that would
150
00:16:38,360 --> 00:16:47,920
allow us to very efficiently move oxygen throughout our body.
151
00:16:47,920 --> 00:16:55,240
Over the course of a day, blood will travel about 12,000 miles through arteries and veins.
152
00:16:55,240 --> 00:17:04,200
It's a system defined by constant motion, something that's also reflected in our evolution
153
00:17:04,200 --> 00:17:14,440
as a species.
154
00:17:14,440 --> 00:17:15,440
Humans are absolutely built to move.
155
00:17:15,440 --> 00:17:19,600
I mean, if you look at our ancestry and the way we used to move around, our musculoskeletal
156
00:17:19,600 --> 00:17:27,260
system is designed for us to be agile, to go long periods of time by moving.
157
00:17:27,260 --> 00:17:30,800
And our hearts can perfectly accommodate this by making sure we get the right amount of
158
00:17:30,800 --> 00:17:34,760
blood when we need it.
159
00:17:34,760 --> 00:17:37,160
But here's the tricky thing.
160
00:17:37,160 --> 00:17:42,840
Not only does our circulatory system allow us to move, it only works properly if we are
161
00:17:42,840 --> 00:17:47,880
living.
162
00:17:47,880 --> 00:17:54,760
For most of us, modern life doesn't involve hunting or crossing continents on foot.
163
00:17:54,760 --> 00:18:00,840
And what we're finding out is that if we stay still for too long, the whole system breaks
164
00:18:00,840 --> 00:18:28,640
down.
165
00:18:28,640 --> 00:18:33,560
Having a bus, you're just sitting there driving.
166
00:18:33,560 --> 00:18:39,600
Day in, day out, eight hours shift.
167
00:18:39,600 --> 00:18:43,800
Sometimes if you're really busy, you may spend your entire shift in the seat because you're
168
00:18:43,800 --> 00:18:51,120
running behind schedule or something.
169
00:18:51,120 --> 00:18:55,320
You're sitting in traffic, sometimes you might sit in the seat for three hours in traffic.
170
00:18:55,320 --> 00:18:59,200
Again, you're not moving.
171
00:18:59,200 --> 00:19:04,360
The advice I give people is just you got to be moving.
172
00:19:04,360 --> 00:19:09,680
You're going to sit down, you're going to die.
173
00:19:09,680 --> 00:19:13,940
I'm a prime example.
174
00:19:13,940 --> 00:19:24,160
I'm Steve Dean and I drive a city bus.
175
00:19:24,160 --> 00:19:29,040
I think one of the life lessons that the cells I've studied has taught me is this
176
00:19:29,040 --> 00:19:33,320
concept of if you don't use it, you lose it.
177
00:19:33,320 --> 00:19:39,000
Cells know what they're doing, but they need to be challenged.
178
00:19:39,000 --> 00:19:43,460
One of the biggest obstacles our circulation is up against is something that we have absolutely
179
00:19:43,460 --> 00:19:50,680
no control over, gravity.
180
00:19:50,680 --> 00:19:52,460
Humans are an upright species.
181
00:19:52,460 --> 00:19:56,040
We walk on two legs.
182
00:19:56,040 --> 00:20:00,520
Once our blood has traveled down the arteries and unloaded oxygen to all the cells below
183
00:20:00,520 --> 00:20:06,900
the heart, that same blood then has to move straight upwards again through our veins to
184
00:20:06,900 --> 00:20:15,060
get back to where it started, working against Earth's gravitational pull the entire time.
185
00:20:15,060 --> 00:20:21,060
In most cases, arteries rely on the heart to pump blood, but veins have to get their
186
00:20:21,060 --> 00:20:26,380
power from another source, muscles.
187
00:20:26,380 --> 00:20:31,820
When you tense your leg muscles, they propel blood upwards.
188
00:20:31,820 --> 00:20:37,620
But this ingenious adaptation only works if the muscles are active, otherwise the pumps
189
00:20:37,620 --> 00:20:41,980
have no energy to work with.
190
00:20:41,980 --> 00:20:45,420
Think about sitting for long periods of time.
191
00:20:45,420 --> 00:20:50,380
Your leg muscles aren't doing anything, so they can't pump that blood back to the heart
192
00:20:50,380 --> 00:20:52,020
with any real force.
193
00:20:52,020 --> 00:20:59,740
And that can lead to major problems.
194
00:20:59,740 --> 00:21:06,540
A bus driver's heart cruising through traffic with no issue is beating at a resting pace.
195
00:21:06,540 --> 00:21:12,300
There is no sense of urgency to increase the heart rate and throw more blood to the body.
196
00:21:12,300 --> 00:21:15,460
You're very sedentary when you're driving the coach.
197
00:21:15,460 --> 00:21:18,060
You sit there a lot.
198
00:21:18,060 --> 00:21:24,900
And that's kind of one of the downfalls of driving the coach.
199
00:21:24,900 --> 00:21:34,380
Back in 2010, when I was working a lot, just sitting there driving, I was up to about 250,
200
00:21:34,380 --> 00:21:37,020
260 pounds.
201
00:21:37,020 --> 00:21:41,220
I felt sluggish.
202
00:21:41,220 --> 00:21:44,780
Our jobs have never been more stationary.
203
00:21:44,780 --> 00:21:48,620
They've moved from farms to cities.
204
00:21:48,620 --> 00:21:55,060
And now onto the internet, and we're constantly told to exercise because the damage can creep
205
00:21:55,060 --> 00:21:59,180
up on you silently.
206
00:21:59,180 --> 00:22:06,540
On general inspection, the heart of a sedentary person might look normal.
207
00:22:06,540 --> 00:22:13,880
However, if you probe more deeply and look, for example, at the arteries that supply blood
208
00:22:13,880 --> 00:22:20,980
to the heart muscle, it's more likely that those arteries would have more signs of fatty
209
00:22:20,980 --> 00:22:28,000
deposits in part because of the sedentary lifestyle.
210
00:22:28,000 --> 00:22:32,640
Not moving actually makes the body worse at processing fat.
211
00:22:32,640 --> 00:22:36,320
And probably everyone on earth will tell you that fat is the enemy.
212
00:22:36,320 --> 00:22:39,400
And here's why.
213
00:22:39,400 --> 00:22:42,540
It's really just a matter of space.
214
00:22:42,540 --> 00:22:47,540
When we exercise, the arteries surrounding the heart expand.
215
00:22:47,540 --> 00:22:53,580
When we don't, they get thinner, and blood needs room to move.
216
00:22:53,580 --> 00:22:59,460
A river can get blocked by rocks, for example.
217
00:22:59,460 --> 00:23:06,040
Similarly, blood vessels can develop blockages called atherosclerosis, which are essentially
218
00:23:06,040 --> 00:23:13,040
fatty deposits that start at the wall and start to protrude inward and eventually impede
219
00:23:13,040 --> 00:23:19,520
blood flow.
220
00:23:19,520 --> 00:23:24,400
These blockages that build over time can get us into real trouble.
221
00:23:24,400 --> 00:23:28,080
I felt this burning in my chest.
222
00:23:28,080 --> 00:23:30,880
I drove myself to St. Peter's emergency room.
223
00:23:30,880 --> 00:23:36,600
They did an EKG.
224
00:23:36,600 --> 00:23:43,320
The doctor, she said, you've had a heart attack.
225
00:23:43,320 --> 00:23:51,840
The heart not only pumps blood to the entire body, but it also pumps blood to itself.
226
00:23:51,840 --> 00:23:53,960
It's self-sustaining.
227
00:23:53,960 --> 00:23:57,600
No other organ does that.
228
00:23:57,600 --> 00:24:04,280
The heart is so hardworking that it needs a constant supply of oxygen and nutrients
229
00:24:04,280 --> 00:24:07,120
to remain functional.
230
00:24:07,120 --> 00:24:15,480
When those arteries get clogged up with fatty deposits, that can result in stoppage of blood
231
00:24:15,480 --> 00:24:19,440
flow to the heart muscle.
232
00:24:19,440 --> 00:24:24,800
When that heart muscle dies, that's called a heart attack.
233
00:24:24,800 --> 00:24:30,680
And unlike other muscles, heart cells barely regenerate.
234
00:24:30,680 --> 00:24:41,040
When they die, scar tissue grows in their place, and scar tissue can't pump.
235
00:24:41,040 --> 00:24:43,160
It was the very tip of an artery.
236
00:24:43,160 --> 00:24:44,240
It was blocked.
237
00:24:44,240 --> 00:24:50,320
They said, if you don't went to sleep, you might not have woke up.
238
00:24:50,320 --> 00:24:52,800
You know, it's an eye-opening experience.
239
00:24:52,800 --> 00:24:56,240
I just realized my time on this earth now has a limit.
240
00:24:56,240 --> 00:25:00,400
It made me realize that I need to do things in my life different.
241
00:25:00,400 --> 00:25:07,160
Oh gosh, we're just about here.
242
00:25:07,160 --> 00:25:10,720
Well, I drive Dialift now.
243
00:25:10,720 --> 00:25:11,720
Good morning.
244
00:25:11,720 --> 00:25:14,840
How are you today?
245
00:25:14,840 --> 00:25:21,960
Dialift is a door-to-door service for passengers with disabilities or elderly.
246
00:25:21,960 --> 00:25:28,240
Everything it prevents them from riding the normal bus.
247
00:25:28,240 --> 00:25:31,400
Marianne is my first rider today.
248
00:25:31,400 --> 00:25:34,360
I take her to Sacred Heart Church.
249
00:25:34,360 --> 00:25:35,360
Is this an express?
250
00:25:35,360 --> 00:25:36,360
Yeah.
251
00:25:36,360 --> 00:25:37,360
You're going straight there today.
252
00:25:37,360 --> 00:25:38,360
Oh good.
253
00:25:38,360 --> 00:25:41,520
That works for me.
254
00:25:41,520 --> 00:25:46,760
I probably added another 3,000 to 4,000 steps a day by driving Dialift.
255
00:25:46,760 --> 00:25:48,640
Good morning, it's Dialift.
256
00:25:48,640 --> 00:25:52,440
You're out of the seat and then you escort them out to the van.
257
00:25:52,440 --> 00:25:54,320
After you, I'll have you go on board there.
258
00:25:54,320 --> 00:25:56,600
And you get them on the lift on the van.
259
00:25:56,600 --> 00:25:58,440
Okay, up we go.
260
00:25:58,440 --> 00:26:00,800
And this step's a little higher.
261
00:26:00,800 --> 00:26:04,920
Sometimes you have your arm out so them to hold on so they're steady.
262
00:26:04,920 --> 00:26:07,080
It's things like that that keep you healthy.
263
00:26:07,080 --> 00:26:08,080
Well here we are.
264
00:26:08,080 --> 00:26:10,080
Yeah, it gets you to work out.
265
00:26:10,080 --> 00:26:13,880
Yay, hey, that's good for you.
266
00:26:13,880 --> 00:26:15,440
You have a wonderful day today.
267
00:26:15,440 --> 00:26:18,160
You feel like a celebrity.
268
00:26:18,160 --> 00:26:25,160
I feel like Steve as always.
269
00:26:25,160 --> 00:26:29,760
If you don't need a strong heart, your body won't give you one.
270
00:26:29,760 --> 00:26:33,800
If you don't need strong muscles, why would your body make one?
271
00:26:33,800 --> 00:26:37,560
So it's in a way like if you don't use it, you lose it.
272
00:26:37,560 --> 00:26:41,360
But if you use it, you get it.
273
00:26:41,360 --> 00:26:44,120
It's been really exciting for me to see this in practice.
274
00:26:44,120 --> 00:26:49,800
You know, with people who are experiencing the increase in strength that can come about
275
00:26:49,800 --> 00:26:54,680
so quickly just by exercising and giving ourselves a little bit of a challenge.
276
00:26:54,680 --> 00:27:01,240
To me it's just very life affirming to think that at any age we always have the opportunity
277
00:27:01,240 --> 00:27:13,880
to adapt and to do better.
278
00:27:13,880 --> 00:27:18,640
The heart and vessels are a mind-bendingly vast system.
279
00:27:18,640 --> 00:27:24,720
But to operate, they need blood.
280
00:27:24,720 --> 00:27:31,760
I mean it's not for nothing that we refer to the metaphorical lifeblood because the
281
00:27:31,760 --> 00:27:35,760
blood is literally the life-giving fluid.
282
00:27:35,760 --> 00:27:36,760
What is blood?
283
00:27:36,760 --> 00:27:40,940
Blood is essentially composed of two substances.
284
00:27:40,940 --> 00:27:48,300
One is the plasma, which is basically salts, water and proteins.
285
00:27:48,300 --> 00:27:53,820
And the other part is the cells.
286
00:27:53,820 --> 00:28:00,100
Red blood cells account for more than 80% of all of our cells and the other 20% rely
287
00:28:00,100 --> 00:28:03,500
on them to survive.
288
00:28:03,500 --> 00:28:10,740
One million times every minute, red blood cells absorb the oxygen that we need to live.
289
00:28:10,740 --> 00:28:14,300
It's an extraordinary piece of our physiology.
290
00:28:14,300 --> 00:28:21,260
Our heart pumps out five to six liters of blood a minute and that blood is constantly
291
00:28:21,260 --> 00:28:27,340
being circulated around the body with new oxygen that's breathed in every few seconds,
292
00:28:27,340 --> 00:28:31,460
with waste products that are being cleaned out on that same time scale.
293
00:28:31,460 --> 00:28:39,300
It powers every moment of our day-to-day lives.
294
00:28:39,300 --> 00:28:44,420
Their never-ending job has given red blood cells a unique structure.
295
00:28:44,420 --> 00:28:49,620
Unlike other cells, they don't have a nucleus.
296
00:28:49,620 --> 00:28:57,620
Instead they're filled with massive quantities of a protein called hemoglobin.
297
00:28:57,620 --> 00:29:02,660
It's made of iron, which is why blood is red.
298
00:29:02,660 --> 00:29:09,260
Hemoglobin grabs onto the oxygen we breathe in, then, at the right moment, it lets go.
299
00:29:09,260 --> 00:29:15,260
And oxygen molecules pass into the surrounding cells.
300
00:29:15,260 --> 00:29:19,620
What's crazy is that hemoglobin is toxic to the human body.
301
00:29:19,620 --> 00:29:25,260
If it escaped from even a tiny fraction of our red blood cells, it could kill us.
302
00:29:25,260 --> 00:29:30,940
But as long as it stays within the cell's walls, it can't harm us.
303
00:29:30,940 --> 00:29:39,040
Red blood cells have a margin of error of exactly zero and they do their job perfectly.
304
00:29:39,040 --> 00:29:45,800
That is, as long as there's enough blood in the body to go around.
305
00:29:45,800 --> 00:29:51,880
Because when we lose blood, everything is then in jeopardy.
306
00:29:51,880 --> 00:29:55,880
And just a few minutes can mean the difference between life and death.
307
00:30:09,040 --> 00:30:18,520
The city of Akra is home to two million people.
308
00:30:18,520 --> 00:30:20,480
It's Ghana's capital.
309
00:30:20,480 --> 00:30:31,200
It's beating heart.
310
00:30:31,200 --> 00:30:40,160
One hundred fifty miles away, over rugged terrain, is the tiny town of Assisunwa, a
311
00:30:40,160 --> 00:30:45,600
place so remote that the word emergency takes on a whole new meaning.
312
00:30:45,600 --> 00:31:05,040
One plus two, one plus two, three.
313
00:31:05,040 --> 00:31:31,000
The bond between mother and child is profound and it starts in the womb.
314
00:31:31,000 --> 00:31:34,880
The first thing they share is blood.
315
00:31:34,880 --> 00:31:42,720
The fetus doesn't breathe, it's floating in amniotic fluid and it only receives oxygen
316
00:31:42,720 --> 00:31:46,200
through the mother's blood supply, through the umbilical cord.
317
00:31:46,200 --> 00:31:52,080
The mother's blood supply also ferries waste out of the fetus, which then gets cleared
318
00:31:52,080 --> 00:31:56,640
by the mother's kidneys.
319
00:31:56,640 --> 00:32:03,600
It's an amazing exchange, but it also means that when something goes wrong with one, both
320
00:32:03,600 --> 00:32:04,600
are in danger.
321
00:32:04,600 --> 00:32:26,200
I'm Dr. Philip Ajamai Perempe, I'm an obstetrician gynecologist at St Michael's Hospital.
322
00:32:26,200 --> 00:32:51,080
We make over 2,000 deliveries every year in this facility.
323
00:32:51,080 --> 00:33:18,520
She came to our maternity emergency.
324
00:33:18,520 --> 00:33:21,040
She was at 36 weeks plus, four weeks.
325
00:33:21,040 --> 00:33:39,360
During the birthing process, the mom and the baby are going through huge amounts of
326
00:33:39,360 --> 00:33:44,480
changes that affect the physical aspects of both infant and mother.
327
00:33:44,480 --> 00:33:49,400
Immediately after the baby is born, the uterus will contract to allow all of those blood
328
00:33:49,400 --> 00:33:53,400
vessels that have been opened during the pregnancy so that the woman actually does
329
00:33:53,400 --> 00:33:58,920
not hemorrhage, meaning she does not continue to bleed too heavily.
330
00:33:58,920 --> 00:34:02,160
For Akua, something had gone very wrong.
331
00:34:02,160 --> 00:34:06,900
The uterus was not contracted.
332
00:34:06,900 --> 00:34:15,160
She was bleeding profusely and we realized that her blood was not clotting.
333
00:34:15,160 --> 00:34:22,440
We lose blood all the time, in small doses, and our bodies can handle it.
334
00:34:22,440 --> 00:34:28,360
But if there's a major bleed that isn't stopping, the body can't recover.
335
00:34:28,360 --> 00:34:33,800
The response has to be lightning fast, and that means a transfusion.
336
00:34:33,800 --> 00:34:41,320
We needed blood to stabilize her and save her life, but we realized we didn't have enough
337
00:34:41,320 --> 00:34:42,320
blood.
338
00:34:42,320 --> 00:34:50,240
And getting blood into a remote area can take hours.
339
00:34:50,240 --> 00:34:57,480
In cases like this, we would ask for an ambulance to bring us the product.
340
00:34:57,480 --> 00:34:59,560
But that takes time.
341
00:34:59,560 --> 00:35:02,440
It was a dilemma and a tough one.
342
00:35:02,440 --> 00:35:10,480
So we called our biomedical scientist and he made an order for us to get blood.
343
00:35:10,480 --> 00:35:17,080
Meanwhile the body starts its own rescue effort, fast, by sending messages.
344
00:35:17,080 --> 00:35:23,360
We have little brains all over our body and the heart has a pretty big one.
345
00:35:23,360 --> 00:35:30,720
It's been recently discovered that there are about 40,000 neurons on the heart.
346
00:35:30,720 --> 00:35:35,920
Nerves that go to the brain as well as nerves that come from the brain.
347
00:35:35,920 --> 00:35:37,840
It's very responsive.
348
00:35:37,840 --> 00:35:45,120
It has the capacity to beat faster or slower to be able to best serve the needs of the
349
00:35:45,120 --> 00:35:49,280
body at any given time.
350
00:35:49,280 --> 00:35:55,200
This group of neurons reacts immediately when blood leaves the body.
351
00:35:55,200 --> 00:36:01,440
Pressure sensors on the heart perceive the loss and they tell the nervous system.
352
00:36:01,440 --> 00:36:07,560
It sends out signals that start a chain reaction to keep cells alive.
353
00:36:07,560 --> 00:36:13,840
It's a highly synchronized effort that depends on instant communication, much like the technology
354
00:36:13,840 --> 00:36:19,480
that Akua's doctors used to contact the only people who could send them blood in time to
355
00:36:19,480 --> 00:36:21,480
save her life.
356
00:36:21,480 --> 00:36:24,480
We're covering in 35 seconds.
357
00:36:24,480 --> 00:36:27,480
One, two, three, eight.
358
00:36:27,480 --> 00:36:28,480
Emergency.
359
00:36:28,480 --> 00:36:29,480
Okay.
360
00:36:29,480 --> 00:36:30,480
We'll get it to you right away.
361
00:37:00,480 --> 00:37:06,560
We had to perform an emergency cesarean section to stabilize her and then to prevent her from
362
00:37:06,560 --> 00:37:09,320
losing more blood.
363
00:37:09,320 --> 00:37:12,560
This is a patient who was very pale.
364
00:37:12,560 --> 00:37:18,720
If we didn't get the blood, it was highly likely that she would bleed to death.
365
00:37:18,720 --> 00:37:20,720
I'm a machine.
366
00:37:20,720 --> 00:37:25,440
I'm a semi-weary.
367
00:37:25,440 --> 00:37:28,540
Very little in the body can happen without blood.
368
00:37:28,540 --> 00:37:34,460
If you empty the heart of blood and stopped it, then the brain and the kidneys and vital
369
00:37:34,460 --> 00:37:39,620
organs wouldn't get oxygen and you'd develop massive organ damage within a period of three
370
00:37:39,620 --> 00:37:41,820
minutes.
371
00:37:41,820 --> 00:37:49,860
The blood is the conduit for all these other organs to function.
372
00:37:49,860 --> 00:37:56,700
If cells go without oxygen for too long, the body goes into irreversible shock.
373
00:37:56,700 --> 00:38:05,060
But the heart brain knows when it's in trouble and its response is smart.
374
00:38:05,060 --> 00:38:11,340
The heart starts to beat faster, breathing becomes shallow and quick.
375
00:38:11,340 --> 00:38:14,460
There's also a chemical reaction.
376
00:38:14,460 --> 00:38:21,180
Hormones flood blood vessels in the skin, causing them to constrict.
377
00:38:21,180 --> 00:38:25,700
Blood moves inward to keep vital organs alive.
378
00:38:25,700 --> 00:38:30,940
That's why people turn pale when they lose blood.
379
00:38:30,940 --> 00:38:39,540
Skin is not so important, but the brain is vital.
380
00:38:39,540 --> 00:38:46,380
It's the body's clever way of redistributing resources.
381
00:38:46,380 --> 00:38:53,740
If the blood loss is really extreme, it might be impossible to reverse the damage.
382
00:38:53,780 --> 00:39:01,980
Tragically, for Akua's unborn child, it was already too late.
383
00:39:01,980 --> 00:39:05,140
But Akua was still holding on.
384
00:39:18,140 --> 00:39:22,300
Within 20 minutes, the plant brought us the blood.
385
00:39:22,300 --> 00:39:29,700
We started transfusing her, and then she was able to pull through.
386
00:39:46,700 --> 00:39:50,940
With some support, the body begins to stabilize.
387
00:39:50,940 --> 00:39:59,940
Our bodies evolved the cardiovascular system to ramp up very, very quickly and ramp down,
388
00:39:59,940 --> 00:40:06,420
because we can't maintain a degree of stress for long periods of time without damaging
389
00:40:06,420 --> 00:40:07,420
the system.
390
00:40:20,940 --> 00:40:43,260
The connection between the brain and the heart is complex and not one-sided.
391
00:40:43,260 --> 00:40:48,580
The structures in the brain regulate the heart through nerve impulses and hormones, and it's
392
00:40:48,580 --> 00:40:53,500
in the brain that emotions and thoughts are processed, even though sometimes it doesn't
393
00:40:53,500 --> 00:40:55,340
seem that way.
394
00:40:55,340 --> 00:41:03,140
Anyone who's ever experienced a sense of panic knows that we feel it immediately in our heart.
395
00:41:03,140 --> 00:41:09,740
So why would it be a surprise that the heart would be really smart at being connected to
396
00:41:09,740 --> 00:41:17,980
our emotional state when that is our internalized experience of the outside world?
397
00:41:17,980 --> 00:41:23,460
So if we feel things in our heart, does that mean it has a mind of its own?
398
00:41:23,460 --> 00:41:29,980
The idea that the heart might be telling the brain how to think or how to feel is an open
399
00:41:29,980 --> 00:41:37,060
question for me personally and one that I think is very hotly debated among scientists.
400
00:41:37,060 --> 00:41:44,300
If there are neurons on the heart, then maybe its power over our emotions isn't just poetic,
401
00:41:44,300 --> 00:41:45,300
but also biological.
402
00:42:14,300 --> 00:42:44,180
My name is Berta Martinez, I am a volunteer at the Lincoln Heights Senior Center.
403
00:42:44,180 --> 00:42:49,940
After we retired, my husband and I started helping at the center.
404
00:42:49,940 --> 00:43:03,700
We love to dance, and we have been attending there for the past 18 years.
405
00:43:03,700 --> 00:43:12,340
We always say that it's our second family.
406
00:43:12,340 --> 00:43:15,860
Humans are social animals.
407
00:43:15,860 --> 00:43:19,540
That's something that we share with primates in general.
408
00:43:19,540 --> 00:43:23,580
We live in groups, and a lot of the way that we navigate the world around us has to do
409
00:43:23,580 --> 00:43:28,620
with social relationships.
410
00:43:28,620 --> 00:43:36,420
This is something that is reflected in our biology.
411
00:43:36,420 --> 00:43:41,940
The brain and the heart are connected by the most powerful neural network in the body.
412
00:43:41,940 --> 00:43:45,460
The vagus nerve.
413
00:43:45,460 --> 00:43:49,140
It passes millions of messages back and forth every day.
414
00:43:49,140 --> 00:43:56,700
The vast majority come not from the brain, but from the heart.
415
00:43:56,700 --> 00:44:02,740
And this network is responsible for communicating emotions.
416
00:44:02,740 --> 00:44:09,180
Positive social interactions light up the vagus nerve in the heart.
417
00:44:09,180 --> 00:44:22,980
In other words, our relationships are constantly shaping our internal worlds.
418
00:44:22,980 --> 00:44:25,420
This is my husband Ricardo.
419
00:44:25,420 --> 00:44:32,660
This picture was taken on our 25th wedding anniversary.
420
00:44:32,660 --> 00:44:36,940
I lost my husband last year.
421
00:44:36,940 --> 00:44:47,180
His chair, my husband, used it all the time to watch TV.
422
00:44:47,180 --> 00:44:52,900
Someone told me, why don't I take everything down so that way I can not feel so bad?
423
00:44:52,900 --> 00:45:00,020
But to me, it's just the opposite.
424
00:45:00,020 --> 00:45:06,700
We know that people who experience intense emotional disturbance, like grief after the
425
00:45:06,700 --> 00:45:14,940
death of a loved one or the breakup of a romantic relationship, can develop severe effects on
426
00:45:14,940 --> 00:45:17,820
their hearts.
427
00:45:17,820 --> 00:45:25,420
The heart in these people tends to acutely weaken and change shape into the shape of
428
00:45:25,420 --> 00:45:33,820
a takosubo, which is a Japanese pot with a narrow neck and a wide base.
429
00:45:33,820 --> 00:45:40,620
It's been variably called the broken heart syndrome or takosubo cardiomyopathy.
430
00:45:40,620 --> 00:45:46,820
And we know that emotional stress can accelerate the development of heart disease and increase
431
00:45:46,820 --> 00:45:52,140
the risk of cardiac mortality.
432
00:45:52,140 --> 00:45:56,020
The exact cause is unknown.
433
00:45:56,020 --> 00:46:01,660
Our best guess is that a super dose of adrenaline floods the heart, shocking cardiac cells,
434
00:46:01,660 --> 00:46:07,140
and weakening them.
435
00:46:07,140 --> 00:46:12,300
Hormones like adrenaline are one of the main ways the brain communicates with the heart.
436
00:46:12,300 --> 00:46:16,340
And the risk of developing takosubo might have something to do with the strength of
437
00:46:16,340 --> 00:46:22,780
neural connections and how they respond to stress.
438
00:46:22,780 --> 00:46:27,340
The same regions in the brain that regulate your heartbeat have been linked to emotional
439
00:46:27,340 --> 00:46:31,580
conditions like depression.
440
00:46:31,580 --> 00:46:37,780
But unlike a heart attack, the cardiac cells are just shocked, not lost.
441
00:46:37,780 --> 00:46:43,580
Fortunately for us, a lot of the injury to the heart is potentially reversible.
442
00:46:43,580 --> 00:46:46,260
The heart does tend to self correct.
443
00:46:46,260 --> 00:46:58,620
So when our emotional states return normal, the heart itself can also return to normal.
444
00:46:58,620 --> 00:47:06,780
I think it's very important to come out even when you're sad.
445
00:47:06,780 --> 00:47:13,700
There is a kind of takosubo cardiomyopathy or broken heart syndrome that occurs after
446
00:47:13,700 --> 00:47:15,540
happy events too.
447
00:47:15,540 --> 00:47:21,760
But the heart shape changes differently.
448
00:47:21,760 --> 00:47:26,780
In the same way that adrenaline can damage cardiac cells, there are other hormones that
449
00:47:26,780 --> 00:47:28,860
can have the opposite effect.
450
00:47:28,860 --> 00:47:35,380
And there's one molecule that's most associated with the complex social behavior of humans.
451
00:47:35,380 --> 00:47:40,260
Oxytocin, often called the love hormone.
452
00:47:40,260 --> 00:47:46,140
Think about the feeling you get when you hug a friend or dance with a flirty stranger.
453
00:47:46,140 --> 00:47:53,260
That rush comes as oxytocin spikes and makes a beeline for the heart.
454
00:47:53,260 --> 00:47:58,380
Just like fear can make your heart pound, the oxytocin released by touch can put your
455
00:47:58,380 --> 00:48:01,100
heart at rest.
456
00:48:01,100 --> 00:48:07,500
Receptors on cardiac cells detect its presence and your heart rate slows.
457
00:48:07,500 --> 00:48:10,900
It also helps reduce inflammation in blood vessels.
458
00:48:10,900 --> 00:48:17,460
So it can actually have a therapeutic effect on stressed arteries and veins.
459
00:48:17,460 --> 00:48:21,140
Even short interactions can stimulate a rush.
460
00:48:21,140 --> 00:48:28,660
So for the heart, love looks like thousands of brief encounters over a lifetime.
461
00:48:28,660 --> 00:48:38,820
Which is really well suited to a function like a dance.
462
00:48:38,820 --> 00:48:44,140
I've been working here 12 years and there hasn't been one Thursday that that place hasn't
463
00:48:44,140 --> 00:48:49,020
filled up with at least 150 people.
464
00:48:49,020 --> 00:48:51,900
Latins like to dance.
465
00:48:51,900 --> 00:48:54,900
Dance is a good exercise.
466
00:48:54,900 --> 00:49:24,460
If you move, it helps a lot, especially at my age.
467
00:49:24,460 --> 00:49:30,180
I think we know that a lack of love can be very damaging.
468
00:49:30,180 --> 00:49:37,660
The corollary to that is can the presence of love be beneficial for the heart?
469
00:49:37,660 --> 00:49:48,980
We know that people in long-standing relationships tend to live longer.
470
00:49:48,980 --> 00:49:56,180
The brain-heart connection is definitely present and is something that we as a field
471
00:49:56,180 --> 00:50:05,700
need to investigate more deeply to really understand its roots.
472
00:50:05,700 --> 00:50:09,420
After my husband passed away, it was hard.
473
00:50:09,420 --> 00:50:14,660
But my second family from the senior center, it gave me so much strength.
474
00:50:14,660 --> 00:50:18,780
It has been easier as time passed by.
475
00:50:18,780 --> 00:50:43,700
Now I'm doing what I love and I'll just keep doing it wherever I can.
476
00:50:43,700 --> 00:50:49,220
How does the body understand the passage of time?
477
00:50:49,220 --> 00:50:56,780
We as humans have a rhythm and a cadence to our life that I believe is in many ways tied
478
00:50:56,780 --> 00:51:01,980
to the heartbeat.
479
00:51:01,980 --> 00:51:16,060
The same pulse inside every one of us, setting the pace for our lives.
480
00:51:16,060 --> 00:51:26,140
With a tiny thump that we often forget about, that's in a way much bigger than we are.
481
00:51:26,140 --> 00:51:29,020
All life has a rhythm.
482
00:51:29,020 --> 00:51:36,860
You just have to pause and take a step back to feel it.
483
00:51:36,860 --> 00:51:43,140
The physical world is made up of pulses of energy, so it's fun to play with that shift
484
00:51:43,140 --> 00:51:49,580
of perspective to think about our bodies more like an ecosystem composed of trillions of
485
00:51:49,580 --> 00:51:55,780
cells conspiring every moment to create our thoughts and keep our heart beating and keep
486
00:51:55,780 --> 00:52:00,580
our breathing going.
487
00:52:00,580 --> 00:52:07,940
The human heart is billions of cells beating billions of times, never pausing.
488
00:52:07,940 --> 00:52:11,140
If we didn't get the blood, it would lead to death.
489
00:52:11,140 --> 00:52:13,340
I lost my husband last year.
490
00:52:13,340 --> 00:52:18,700
Intense emotional disturbance can accelerate cardiac mortality.
491
00:52:18,700 --> 00:52:20,940
Cells need to be challenged.
492
00:52:20,940 --> 00:52:23,060
If you don't use it, you lose it.
493
00:52:23,060 --> 00:52:24,740
I felt this burning in my chest.
494
00:52:24,740 --> 00:52:43,140
I said, if you don't want to sleep, you might not have woke up.
495
00:52:43,140 --> 00:52:50,100
To order Human, The World Within on DVD, visit shoppbs.org or call 1-800-PLAY-PBS.
496
00:52:53,060 --> 00:52:54,060
1-800-PLAY-PBS.
497
00:52:54,060 --> 00:52:55,060
1-800-PLAY-PBS.
498
00:52:55,060 --> 00:52:56,060
1-800-PLAY-PBS.
499
00:52:56,060 --> 00:52:57,060
1
500
00:52:57,060 --> 00:52:57,060
45849
Can't find what you're looking for?
Get subtitles in any language from opensubtitles.com, and translate them here.