Building muscles: Muscle stem cells (their nuclei marked in blue) gradually alter their structure and function, becoming adult muscle cells (whose nuclei turn red). Those cells will eventually fuse ...

Stem cells that live in the muscle impart its ability to regenerate. After an injury, muscle stem cells activate and must expand in number to repair and make new muscle (marked by dystrophin in white) ...

As we age, the muscles we rely on for daily activities tend to become less reliable. With enough decline, even normal movements such as getting out of bed become risky. Low muscle mass in the ...