The descending aorta is divided into two sections that are named for their location.

降主分为两个部分，以其位置命。

Lastly, G is for great vessels which includes the superior vena cava, inferior vena cava, ascending aorta, aortic arch, pulmonary artery, and descending aorta.

最后，G指大管" Great vessels" ，包括了上腔静、下腔静、升主、主弓、肺与降主。

In this lesson, you will learn about the descending aorta, which begins at the aortic arch and is divided into two sections, the thoracic and the abdominal aorta.

本节课，我们将学习降主，主弓开始，分为两部分，胸主和腹主。

After exiting the heart, the aorta makes a U-turn at the aortic arch and becomes known as the descending aorta as it plunges down through the thorax and abdomen.

主离开脏后，在主弓处作一个U形转弯，当穿过胸腔和腹部时，被称为降主。

The main thing to note about the descending aorta is that it has a number of branches coming off of it, much like back roads would come off of a highway.

关于降主，需要注意的主要问题是有许多分支降主上分支，就像小道高速公路上分支一样。