1.The coronary arteries start up in the epicardium, and then dive down and supply all the heart tissue.

冠状动脉在心外发出，然后深入所有心脏组织。

2.So, moving from the outside of the heart to the inside of the heart: after the epicardium, there's the myocardium, which is the muscular middle layer.

从心脏的外侧到心脏的内部：在心外后，有心肌层，即中间的肌肉层。

3.The inner layer is called the visceral layer, and it gets stuck tightly to the heart itself, forming the epicardium - or the outer layer of the heart.

而内层被称为脏层，地贴合在心脏上，形成心外，即心脏外层。

4.Meanwhile, the inner serous pericardium consists of an inner visceral layer, or epicardium — which is actually part of the heart wall — and an outer parietal layer.

同时，内部浆液性心包由内部内脏层或心外——实际上是心壁的一部分——和外部顶层组成。

5.The muscular walls of the heart consist of three major " layers" . The bulk of the walls is made up of a layer of cardiac muscle and is called the myocardium.

心肌外层是心外，内层是心内。

6.Whatever the case, the heart needs blood, and if we look at the heart wall, there's three layers—the outermost layer, the epicardium, then the myocardium in the middle, and the endocardium inside the heart.

无论什么情况下，心肌都需要血，我们学习心壁时知道，心壁有3层：最外层的心外、中层的心肌，以及心脏内的心内。