cardiac muscle

例句：

1. 1. The heart's cardiac muscle is responsible for pumping blood throughout the body.
   心脏的心肌负责将血液泵送到全身。
2. 2. Cardiac muscle is a critical component of thehuman heart.
   心肌是人体心脏的关键组成部分。
3. 3.During exercise, the cardiac muscle becomes strongerand more efficient.
   在运动时，心肌变得更强壮、更高效。