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。

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。

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。

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。

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。

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。

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。

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。

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。

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。

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。

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。

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。

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。

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。

What we don't have is any deoxygenated blood escaping into the systemic circulation and causing a baby to appear cyanotic, so we call this acyanotic, which means " not blue" .

这时不会有缺氧血流入体循环而引起婴儿出现发绀，所以我们称之为不发绀，即无青紫。

When deoxygenated blood mixes into the systemic circulation, it'll often present as cyanosis, a bluish-purple discoloration of the skin, which can be seen in a baby within the first days after birth.

当无氧血混入体循环，会表现为发绀，一种皮肤变为青紫色的症状，在出生后几天便可发现。

This is a good way to think about the superior vena cava, because its job is to drain (or return) deoxygenated blood straight down into the right atrium.

这是考虑上腔静脉的好方法，因为它的工作是将脱氧的血液直接排入（或回流）到右心房中。

From there — and this is the only time in your body where deoxygenated blood goes through an artery — the blood goes straight through the pulmonary artery into the lungs, where it can pick up oxygen.

这是体内唯一一次缺氧血液通过肺动脉，血液直接穿过肺动脉进入肺部，在肺部吸收氧气。

In other words, it drains deoxygenated blood from the legs, back, abdomen and pelvis, and then it transports them all the way up to the right atrium of the heart.

换句话说，它从腿部、背部、腹部和骨盆排出脱氧血，然后将它们一直输送到心脏的右心房。