Biology Forums - Study Force

I have the majority of it done, but am having trouble with the following questions:


10.    For Activity 6, explain how you were able to achieve smooth contraction at a given force level.

11.    In Activity 7, explain why the force of the muscle decreased over time during uninterrupted stimulation. Describe the multiple causes of this phenomenon, which occurs in vivo with prolonged use of a muscle.



12.    In Activity 8, at what length of the muscle does the passive force start to increase?



16.    In Activity 9, which weight resulted in the highest initial velocity of shortening?
17.    Explain the relationship between the amount of resistance and the initial velocity of shortening.

18.    Explain why it will take you longer to perform 10 repetitions lifting a 20-pound weight than it would to perform the same number of repetitions with a 5-pound weight.


Any help would be appreciated. I haven't seen anything on the review sheets on here. Thanks!

Hello! How funny I am stuck with #3,4, 8, 9 and 14 but have everything else.

10. We had to adjust the frequency and intensity to achieve the given level.

11. Fatigue is when it loses force and this is due to the ATP consumption being faster than it's production. There can also be changes due to the sarcomere length-tension relationship due to repeated contraction.

12. About 70mm

16. .5 grams

17. When something is light it has a shorter initial velocity needed because it's easier/less energy to lift.

So using what I just answered for question 17 you should be able to answer 18 on your own now. Can you provide any help for me on the ones I'm stuck with? #3,4,8,9,14

Remember to keep posting and contributing to the forums! :)

So is this solved?

Thanks! I thought I had 8, but I don't. Here are the others you are looking for, though.

3. From Activity 3, describe the effect of increasing the voltage. What happened to the force generated and why did this change occur? The higher voltage resulted in higher force and higher contractile force.

4. How does this change occur in vivo?Tthe more stimulus of muscle require more work on the cells which requires more Ca+2 to facilitate this stimulus increase.

9.    Explain how wave summation and recruitment are achieved in vivo.
   Summation is achieved by the nervous system increases firing rate of motor neurons. Recruitment is caused by neural activation of increasingly large numbers of motor units serving the muscle.  (This is from Duddy in a separate thread)


14.    Explain what happens to the active force with a decrease in the muscle length.
      Active force decreases as muscle length increases.
   

Nice :D

I also was having troubles with afew of these thanks for posting!!

thanks for the help!!