So that blood goes from the pulmonary artery into a pulmonary arteriole, which is a little bit smaller and, finally, into a capillary which is the smallest.

肺动脉进入较细小的肺小动脉，最后进入毛细管。

Notice though, that this one big artery does split into the aorta and pulmonary artery.

注意，这条大动脉确实会分成主动脉和肺动脉。

The right ventricle pumps blood through the pulmonary semilunar valve into the pulmonary trunk, which is just a big vessel that splits to form the left and right pulmonary arteries.

右心室通过肺半月瓣泵入肺动脉干，肺动脉干只是一个大管，它分裂形成左右肺动脉。

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心脏通往肺部、携带缺氧的肺动脉中。

And that's up in the pulmonary artery. The wire lead acts like permanent paddles on a heart.

在肺动脉上。导线的作用就像心脏上的永久性划片。

This trip from the right ventricle of the heart, through the pulmonary artery to the lungs, and back to the left atrium of the heart is called the pulmonary circulation.

心脏右心室，经过肺动脉到肺，再由肺静脉回到心脏左心房的行程，被称为肺循环。

A backup of blood in the pulmonary veins and capillary beds can increase the pressure in the pulmonary artery and can also result in fluid moving from the blood vessels to the interstitial space causing pulmonary edema, or congestion.

而在肺静脉和毛细管的积留，会提升肺动脉的压力，还会导致体管流入组织间隙，引起肺水肿。

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通过肺动脉，直接穿过肺动脉进入肺部，在肺部吸收氧气。

Once it's passed the pulmonary valve, the blood goes into the pulmonary arteries, which carry blood away from the heart to the left and right lung.

一旦通过肺动脉瓣，便会进入肺动脉；肺动脉心脏输送到左肺和右肺。

Remember how fluid buildup increased pressure in the pulmonary artery?

还记得体积聚如何增加肺动脉压力吧？

On the left side, blood's now pumped from the left ventricle out to the pulmonary artery to the lungs, and then comes back to the left atrium and left ventricle and restarts.

对于左边来说，现在左心室泵到了肺动脉进入肺，最后回到左心房，再进入左心室，然后重复这一循环。

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

不过，来自肺动脉的不含氧。

Blood flows from the left ventricle into the aorta and from the right ventricle into the pulmonary arteries.

左心室流入主动脉，以及右心室流入肺动脉。

It takes a little bit longer for the right ventricle to squeeze the extra blood into the pulmonary arteries and it takes a little bit longer for the pulmonary valve to close.

这使右心室需要更长的时间多余的挤入肺动脉；同时，肺动脉关闭的时间变长。

Less commonly, babies can have levo-transposition of the great arteries, or l-TGA, with levo meaning that the aorta's primarily to the " left" of the pulmonary artery.

更少见地，宝宝可能会有左旋-大动脉转位，即L-TGA，左旋的意思是主动脉主要位于肺动脉的左侧。

Since there's more oxygenated blood over here, patients will have an increased oxygen saturation in the right ventricle and pulmonary artery.

既然来了更多含氧高的，患者右心室和肺动脉的氧饱和度就升高了。

This isn't good, and this situation is actually called complete TGA, or sometimes dextro-TGA or d-TGA, dextro meaning " right" , since in this case, the aorta's in front of and primarily to the right of the pulmonary artery.

这种情况不太妙，被称为完全TGA，有时也叫右旋TGA或者d-TGA，dextro的意思是右旋的，因为这种情况下，主动脉在肺动脉的前面并且主要在肺动脉的右边。

If these two great arteries, the aorta and pulmonary artery, don't divide, you essentially have this massive artery coming from both ventricles.

如果主动脉和肺动脉这两条大动脉不分开的话，你就会有这条心室发出的大动脉。

From there the blood goes into the right ventricle and gets pumped into pulmonary artery and eventually into the lungs.

接着，右心房进入右心室并被泵入肺动脉，最终进入肺。

Alright, so to help visualize this, I'm going to switch to this super simplified version of the heart since it's better at showing the relationship between the aorta, branches, pulmonary artery, and ductus arteriosus.

为了可视化，我使用这张极简版的心脏图，因为它能更好地显示主动脉及其分支、肺动脉、动脉导管之间的关系。