How do lungs work Emma Bryce

Many of us have hundreds of things
on our minds at any moment,

often struggling to keep track
of everything we need to do.

But fortunately,

there’s one important thing
we don’t have to worry about remembering:

breathing.

When you breathe, you transport oxygen
to the body’s cells to keep them working

and clear your system
of the carbon dioxide

that this work generates.

Breathing, in other words,
keeps the body alive.

So, how do we accomplish
this crucial and complex task

without even thinking about it?

The answer lies
in our body’s respiratory system.

Like any machinery,
it consists of specialized components,

and requires a trigger
to start functioning.

Here, the components are the structures
and tissues making up the lungs,

as well as the various other
respiratory organs connected to them.

And to get this machine moving,
we need the autonomic nervous system,

our brain’s unconscious control center
for the vital functions.

As the body prepares
to take in oxygen-rich air,

this system sends a signal
to the muscles around your lungs,

flattening the diaphragm

and contracting the intercostal muscles
between your ribs

to create more space
for the lungs to expand.

Air then wooshes into your nose and mouth,

through your trachea,

and into the bronchi
that split at the trachea’s base,

with one entering each lung.

Like tree branches, these small tubes
divide into thousands of tinier passages

called bronchioles.

It’s tempting to think of the lungs
as huge balloons,

but instead of being hollow,
they’re actually spongy inside,

with the bronchioles running
throughout the parenchyma tissue.

At the end of each bronchiole
is a little air sack called an alveolus,

wrapped in capillaries
full of red blood cells

containing special proteins
called hemoglobin.

The air you’ve breathed in
fills these sacks,

causing the lungs to inflate.

Here is where the vital exchange occurs.

At this point, the capillaries
are packed with carbon dioxide,

and the air sacks are full of oxygen.

But due to the basic process of diffusion,

the molecules of each gas
want to move to a place

where there’s a lower concentration
of their kind.

So as oxygen crosses over
to the capillaries,

the hemoglobin grabs it up,

while the carbon dioxide
is unloaded into the lungs.

The oxygen-rich hemoglobin
is then transported throughout the body

via the bloodstream.

But what do our lungs do
with all that carbon dioxide?

Exhale it, of course.

The autonomic nervous system
kicks in again,

causing the diaphragm to ball up,

and the intercostal muscles to relax,

making the chest cavities smaller
and forcing the lungs to compress.

The carbon dioxide-rich air is expelled,
and the cycle begins again.

So that’s how these spongy organs keep
our bodies efficiently supplied with air.

Lungs inhale and exhale
between 15 and 25 times a minute,

which amounts to an incredible
10,000 liters of air each day.

That’s a lot of work, but don’t sweat it.

Your lungs and
your autonomic nervous system

have got it covered.

我们中的许多
人在任何时候都有数百件事在我们的脑海中,

经常努力跟踪
我们需要做的一切。

但幸运的是,

我们不必担心记住一件重要的事情

呼吸。

当你呼吸时,你将氧气输送
到身体的细胞,以保持它们的工作

并清除你的系统

中这项工作产生的二氧化碳。

换句话说,呼吸
使身体保持活力。

那么,我们如何不假思索地完成
这项关键而复杂的任务

呢?

答案
在于我们身体的呼吸系统。

像任何机器一样,
它由专门的组件组成

,需要触发器
才能开始运行。

在这里,组件是构成肺的结构
和组织,

以及与之相连的各种其他
呼吸器官。

为了让这台机器运转,
我们需要自主神经系统,即

我们大脑对重要功能的无意识控制中心

当身体
准备吸入富含氧气的空气时,

该系统会向
肺部周围的肌肉发送信号,

使横膈膜变平

并收缩肋骨
之间的肋间肌肉,

从而
为肺部扩张创造更多空间。

然后空气进入你的鼻子和嘴巴,

通过你的气管

,进入
在气管底部分裂的支气管,

每个肺部都有一个。

像树枝一样,这些小管子
分成数千个

称为细支气管的细小通道。

人们很容易将肺想象
成一个巨大的气球

,但它们不是空心的,而是
内部实际上是海绵状的,

细支气管
贯穿于肺实质组织。

每个细支气管的末端
都有一个叫做肺泡的小气囊,它

包裹在
充满红细胞的毛细血管中,

其中含有
称为血红蛋白的特殊蛋白质。

你呼吸的空气
充满了这些袋子,

导致肺部膨胀。

这是重要的交换发生的地方。

此时,毛细血管
中充满了二氧化碳

,气囊中充满了氧气。

但是由于扩散的基本过程,

每种气体的分子
都想移动到同类

浓度较低的地方

因此,当氧气
越过毛细血管时

,血红蛋白将其吸收,

而二氧化碳
则被卸载到肺部。

然后富含氧气的
血红蛋白通过血液输送到全身

但是我们的肺对
这些二氧化碳做了什么?

呼气,当然。

自主神经系统
再次启动,

导致横膈膜向上弹起

,肋间肌肉放松,

使胸腔变小
并迫使肺部压缩。

富含二氧化碳的空气被排出
,循环再次开始。

这就是这些海绵状器官如何
有效地为我们的身体提供空气。


每分钟吸气和呼气 15 到 25 次,

这相当于每天惊人的
10,000 升空气。

这是很多工作,但不要出汗。

你的肺和
你的自主神经系统

已经覆盖了它。