From the outside in, these are the adventitia, or serosa; the muscular layer; the submucosa and the mucosa.

从外到内看，分别是外膜（或者说浆膜）、肌层、黏膜下层与黏膜。

In addition there is a thick muscular layer called the detrusor muscle that helps with bladder contraction during urination and it has fibrous adventitia outer layer.

此外，还有一层较厚的肌肉层，称为逼尿肌，能辅助排尿过程，其外层有纤维外膜。

Normally, the wall of the entire gastrointestinal tract is made of 4 layers: the inner mucosa, the submucosa, a muscular layer, and an outer layer called the adventitia.

正常情况下，整个胃肠道的壁由4层组成：粘膜层、粘膜下层、肌层和外层（即外膜）。

Because of this difference, the left ventricle needs to be stronger; and so the muscular layer of the left ventricular wall or its myocardium is three times thicker than the right ventricle's myocardium.

由于这种差异，左心室需要更强壮；因此左心室壁的肌肉，即心肌，比右心室的心肌厚三倍。

The bladder is able to expand and contract because it's wrapped in a muscular layer, called the detrusor muscle, and within that, lining the bladder itself is a layer of transitional epithelium containing " umbrella cells" .

膀胱既可以扩张也可以收缩，因为膀胱壁有一层肌肉，叫做逼尿肌，而且膀胱内衬有一层由“伞状细胞”（盖细胞）组成的变移上皮。

Placental abruption is often accompanied by pain in the area of the abruption, and the uterus may tense up and become rigid as the strong muscular layer contracts to clamp down on the uterine vessels to reduce the bleeding.

胎盘早剥经常伴有剥离部位的疼痛，而子宫也可能紧张而变得僵硬，这是由肌肉强烈收缩以减少子宫血管出血导致的。