But the pressure gets lower, which means the partial pressure of oxygen also decreases to about 45 millimeters of mercury at the top of Mt. Everest.

但是压力变低了，这意味着在珠穆朗玛峰山顶，氧气的分压也下降到大约 45 毫米汞柱。

Meaning the partial pressure of oxygen was only 16 kilopascals, the minimum required for people on the plane to feel normal.

这意味着氧气分压只有16千帕，这是飞机上的人感觉正常所需的最低值。

So the partial pressure of oxygen at the top of the highest peak in the world, is almost the same as the de-oxygenated blood that's entering your lungs.

所以氧气分压在世界最高峰的顶端，几乎与进入肺部的脱氧血液相同。

The partial pressure of oxygen is 100 mmHg in alveolar air compared to only 40 mmHg in the blood entering the lungs.

肺泡空气中的氧分压为100 mmHg，而进入肺部的血液中只有40 mmHg。

The graph you see below illustrates the effects of an increased partial pressure of oxygen on percent saturation of hemoglobin with oxygen.

下图说明了氧分压增加对血红蛋白氧饱和度的影响。

Therefore, the partial pressure of oxygen is 100 mmHg and the partial pressure of carbon dioxide is 40 mmHg in the blood leaving the lungs.

因此，离开肺部的血液中氧分压为100 mmHg，二氧化碳分压为40 mmHg。

But since only about 21 percent of that air is oxygen, oxygen's part of that pressure — or partial pressure of oxygen — is 21% of 760, or about 160 millimeters of mercury.

但是由于空气中只有大约 21% 是氧气，氧气的部分压力——或者氧气的分压——是 760 的 21%，或者大约 160 毫米汞柱。

Since the partial pressure of oxygen is lower in the blood entering the lungs than it is in the alveolar gas, oxygen diffuses into the blood.

由于进入肺部的血液中的氧分压低于肺泡气体中的氧分压，因此氧气扩散到血液中。

At sea level, this reduces the partial pressure of oxygen from 160 mmHg to about 100 mmHg, as 13% of 760 mmHg is about 100 mmHg.

在海平面，由于760mmhg中13%的氧分压约为100mmhg，因此将氧分压从160mmhg降低到约100mmhg。

When that air mixes with the air deep in your lungs — including a lot of air that you haven't exhaled yet — the partial pressure of oxygen drops to about 104 millimeters of mercury.

当这些空气和你肺部深处的空气混合时——包括许多你还没有呼出的空气——氧气的分压下降到大约 104 毫米汞柱。

Since the partial pressure of oxygen in the alveolar air is 100 mmHg, so also is the partial pressure of oxygen in the blood as it leaves the lungs.

由于肺泡空气中的氧气分压为100 mmHg，因此血液离开肺部时的氧气分压也是如此。

Red blood cells saturated with oxygen are going to the muscle tissue in your quads, where the hemoglobin can dump a bunch of O2, because of the lower partial pressures of oxygen in your muscles.

充满氧气的红细胞正在进入你四头肌的肌肉组织，血红蛋白可以在那里释放一堆氧气，因为你肌肉中的氧气分压较低。

Before pressurization, planes would fly up to 10,000 feet or around three kilometers, where the partial pressure of oxygen is 15 kilopascals, just at the limit of what people can handle.

在加压之前， 飞机可以飞到10,000英尺或大约3公里的高度，此时的氧气分压为15千帕，刚好是人类能够承受的极限。

As air moves into the alveoli, water vapor and carbon dioxide are added, and that reduces the partial pressure of oxygen to about 100 mmHg in the alveolar gas.

当空气进入肺泡时，水蒸气和二氧化碳被加入其中，这使得肺泡气体中的氧分压降低到大约100 mmHg。

To be clear, the air is still 21% oxygen, but the partial pressure of oxygen, the pressure exerted solely by oxygen molecules is around 5.5 kilopascals, which is a quarter of what it is on the ground.

需要明确的是，空气中仍然含有 21% 的氧气，但氧气的分压（仅由氧气分子施加的压力）约为 5.5 千帕，是地面压力的四分之一。