| A | B |
|---|
| Origin | The part of the skeletal muscle that is attached to a bone or structure. |
| Insertion | The end of the muscle that is attached to a moveable part; moves most during a muscle contraction |
| Belly | Central body of the muscle |
| Prime mover | one part of the pair of muscles that produces movement in a single direction. |
| Antagonist | One part of the pair of muscles that produces movement in a single direction. |
| Synergists | The group of muscles that help to steady movement or stabilize joint activity |
| Heat | caused by muscles working, produced by muscles. |
| Motor Unit | a Motor Nueron plus all the muscle fibers it stimulates. |
| Muscle Fatigue | Caused by an accumulation of lactic acid in the muscles |
| Muscle Tone | when muscles are slightly contracted and ready to pull. Achieved through proper nutrition and regular exercise |
| Isontonic | When Muscles contract and shorten (walking, talking) |
| Isometric | when muscle contraction occurs but does not shorten (tensing abdominal muscles) |
| Atrophy | caused when muscles aren't used, they shrink. |
| Hypertrophy | caused when muscles are over-exercised and muscle fiber enlarges |
