Both the cells of the tunica intima and tunica media generally get the nutrients they need from the blood in the lumen.

内膜和中膜的细胞，都能从管腔内的血液中获取所需的营养物质。

Surrounding the tunica intima is the middle layer, the tunica media, made of smooth muscle cells and sheets of the protein elastin.

围绕内膜的是中间层，中膜，由平滑肌细胞和蛋白质弹性蛋白片组成。

The innermost tunic is called the tunica intima, which includes the endothelial cells, which create a slick surface that minimizes friction for blood moving through it.

最内层者称为内膜，有内皮细胞构成；它们形成了光滑表面，使血液流经时的摩擦降到最低。

Anatomists call these layers " tunics, " and the innermost section is the tunica intima — which should be pretty easy to remember because, you know, it has like intimate contact with the lumen. It's like your circulatory underpants.

解剖学家称这些层为束腰外衣，最里面的部分是内膜——这应该很容易记住，因为，你知道，它和内腔有亲密的接触。就像你的循环内裤。