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纤维捆绑形成你的肌肉纤维吗？

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.

数以千计被称为肌原纤维的微小平行线挤压在一起形成肌肉纤维，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。