cardiac vein

例句：

1. 1.The cardiac vein is responsible for carrying oxygenated blood back to the heart.
   心脏静脉负责将氧气化的血液输送回心脏。
2. 2. Cardiac veins are often used in medical imaging to visualize the heart's structure.
   心脏静脉常用于医学成像，以可视化心脏的结构。
3. 3.During exercise, the cardiac veins dilate to increase blood flow to the muscles.
   在运动时，心脏静脉扩张以增加肌肉的血流。