| A | B |
|---|
| muscular system | body system that moves bones within and substances throughout the body |
| muscle fiber | cell of the muscular system that shortens when it is stimulated by the nervous system |
| skeletal muscle | muscle tissue that is attached to the skeletal system and, when contracted, moves bones |
| tendon | band of connective tissue that joins a muscle to the bone that it moves |
| smooth muscle | muscle tissue that moves substances, such as food and blood, through organs and tissues, such as the digestive system organs and blood vessels |
| cardiac muscle | muscle tissue that is only found in the heart |
| myofibril | long strand of protein within a muscle fiber |
| sarcomere | section of a muscle fiber that contains all of the filaments necessary to cause muscle contraction |
| actin | filament that is pulled by myosin filaments to cause muscle contraction |
| myosin | filament that pulls actin filaments to cause muscle contraction |
