During muscle contraction, the part that does not get shortened in length is labeled as the letter:
1. A | 2. B |
3. C | 4. D |
What happens during the contraction of a skeletal muscle fiber?
1. | The myosin filaments stay the same size but the actin filaments shorten |
2. | The sarcomeres shorten |
3. | The actin filaments stay the same size but the myosin filaments shorten |
4. | Both actin and myosin filaments shorten |
I: | Repeated activation of muscles can lead to fatigue. |
II: | Repeated activation of muscles can lead to accumulation of lactic acid. |