This time, though, that blood comes from the pulmonary arteries, carrying deoxygenated blood.

不过，来自肺动脉的血液不含氧。

Blood on the right side therefore never gets oxygenated, and blood on the left side never gets deoxygenated.

从右心室出来的血液不会被氧化，同样，从左心室出来的血液不会去氧化。

Now, deoxygenated blood then feeds back into larger and larger veins, and goes back to the heart.

之后，脱氧的血液逐级回流到静脉血管中，并最终返回心脏。

The greater the pulmonary obstruction, the more deoxygenated blood enters the systemic circulation, the more severe the symptoms.

肺动脉梗阻越严重，越多低氧的血进入全身循环，症状越严重。

Even though they eventually split off, before that it's just one single vessel, so the oxygenated and deoxygenated blood mix.

但即使它们最终分开了，在分开前还是一条血管，因此有氧血和无氧血混合了。

Your veins drain deoxygenated blood from your body tissues and return it to the heart.

静脉从身体组织中排出脱氧的血液，然后将其返回心脏。

The venae cavae empties the deoxygenated blood into the right atrium of the heart.

腔静脉将脱氧血注入心脏的右心房。

Now, deoxygenated blood is escaping out to the systemic circulation, and being pumped out to the whole body via the aorta.

这时，含氧少的血液逃到体循环去了，并且通过主动脉泵到全身各部位。

Especially since rusty metal can create jagged wounds with lots of deoxygenated dead tissue for them to latch on to.

尤其是生锈的金属会造成锯齿状伤口，伤口处会有大量缺氧的死组织，它们会依附在这些组织上。

At this point, carbon dioxide diffuses out from the deoxygenated blood and into the air of the alveoli, which then gets breathed out.

此刻，二氧化碳由血液扩散入肺泡，之后被呼出。

Its job is to return deoxygenated blood to the heart from the head and arms.

其作用是将脱氧血从头部和手臂送回心脏。

The pulmonary arteries carry deoxygenated blood from the heart to the lungs.

肺动脉将脱氧血从心脏输送到肺。

In this lesson, we'll learn about the main blood vessels that return deoxygenated blood to the heart.

本节课，我们将学习将脱氧血送回心脏的主要血管。

This usually occurs in the deep veins of the legs or in the pulmonary arteries that carry deoxygenated blood from the heart to the lungs.

这经常发生在腿部的深静脉或从心脏通往肺部、携带缺氧血的肺动脉中。

Veins are a passive, more limpy process because it's the bottom number of millimeters of mercury on your blood pressure, and it's the blood that is now deoxygenated.

静脉是一个被动的、更脆弱的过程，因为它是血压的最底层毫米汞柱，现在血液缺氧了。

And this is particularly dangerous because it sets up a vicious cycle of congested, deoxygenated red blood cells preventing other red blood cells from getting oxygen.

这十分危险，因为它会造成恶性循环：拥堵的脱氧红细胞会阻碍其它红细胞氧合。

This results in cyanosis in the lower extremities, a blue or purple discoloration of the skin; that's the result of deoxygenated blood mixing with oxygenated blood.

这会导致下肢的发绀，即皮肤变蓝或青紫，是由缺氧血和氧合血混合造成的。

Deoxygenated blood from the body enters the heart at the right atrium and passively travels past the tricuspid valve to fill the right ventricle.

来自身体的脱氧血进入右心房的心脏，被动地通过三尖瓣注入右心室。

If you're unfamiliar with that technology, essentially, an fMRI machine is a big, tubular magnet that tracks the progress of deoxygenated iron in your blood.

如果您不熟悉这项技术， 从本质上讲， fMRI 机器是一个大型管状磁铁，可以跟踪血液中脱氧铁的进程。

Now, you've got deoxygenated blood flowing into the aorta and generally heading to the lower extremities since the upper extremities and head typically have arterial branches upstream from the PDA.

这部分未经过氧合的血进入了主动脉后，通常流入了下肢，这是由于供应上肢和头部的血管来自主动脉上位于动脉导管上游的分支。