venae atriales

例句：

1. 1. The heart's ventricles are the main chambers responsible for pumping blood.
   心脏的四个腔室主要负责泵血。
2. 2. Venous return is the process by which oxygenated blood returns to the heart.
   静脉回流是氧气化血液返回心脏的过程。
3. 3. During sleep, the heart's atria fill with blood and relax, allowing it to be pumped out.
   在睡眠期间，心脏的心房充满血液并放松，以便被泵出。