Two questions about physiology lab?

[Jonybhai]

Hi
In frog muscle tetanization experiment:
1.Why do we see incomplete tetanization then the complete tetanization?
2. What will happen if we continue stimulating the frog muscle while it is in a complete tetanization?
Thanks in advance

[LeslieSamuel]

When you continue stimulating the frog muscle and the muscle contractions overlap, calcium doesn't have enough time to get pumped back into the sarcoplasmic reticulum. If you you stimulate it fast enough, it will cause more calcium to be released, resulting in an increased contraction. When you continue to do this, this will cause the amount of calcium release to reach maximum levels, resulting in complete tetanization.

If you continue to do this even more, the muscle can eventually run out of ATP, which is also needed for contraction to happen. If you run out of ATP, it doesn't matter how much you stimulate the muscle, it will no longer contract.