atrioventricular veins

例句：

1. 1.The atrial appendage is an important structure in the heart's physiology.
   房室结是一个心脏生理学中的重要结构。
2. 2. The atrial appendage plays a crucial role in the proper functioning of the heart.
   房室结在心脏的正常功能中起着至关重要的作用。
3. 3.The atrial appendage is often overlooked in the study of cardiac disease.
   房室结在研究心脏病时常常被忽视。