Now, remember those tiny myofibrils that bundle up to form your muscle fibers?

现在，还记得那些微小的肌原形成你的肌肉吗？

Thousands of tiny, parallel threads called myofibrils squish together to form muscle fibers, which are your actual muscle cells — cells with mitochondria, multiple nuclei, and a cellular membrane called a sarcolemma.

以千计被称为肌原的微小平行线挤压在一起形成肌肉，这就是你真正的肌肉细胞——具有线粒体、多个细胞核和称为肌膜的细胞膜的细胞。