7.) Skeletal muscle function- Length- tension relationship

in this experiment, when the muscle is stretched, what happens to the length of the muscle fibers?

-the muscle fibers get longer

-they stay the same

-the muscle fibers get shorter

-the muscle fibers get longer

Since muscle fibers are composed of a series of sarcomeres laid down next to another, then what happens to the length of the sarcomeres when the muscle fibers are stretched?

-The sarcomeres get longer

-the sarcomeres stay the same

-the sarcomeres get shorer

-The sarcomeres get longer

Initially, you applied a shock to the shortened muscle and measured the tension. You then stretched the muscle and repeated the experiment. Did the amount of tension:

-Decrease as the muscle was stretched to about 28mm

-remain constant as the mucle was stretched to about 28mm

-increase as the muscle was stretched to about 28mm

-increase as the muscle was stretched to about 28mm

the amount of tension produced by the muscle depends upon the number of crossbridges, according to your data did the number of crossbridges:

-decrease as the muscle was lengthened

-increase as the muscle was lengthened to about 28m

remain constant as the muscle was lengthened

-increase as the muscle was lengthened to about 28m

According to your data, a single contraction produced maximum tension when the muscle was held at

-about 26mm

-about 28mm

-about 30mm

-about 28mm

If the max tension indicates that the thick and thin filaments are set at optimal overlap to produce a max number of crossbridges, further stretching of the muscle will

-increase the amount of thick and think filament overlap

-not change

- decrease the amount of thick and think overlap

- decrease the amount of thick and think overlap

Since tension produced by contracting muscle fiber depends upon the numeber of crossbridges between thick and think filaments then stretching the muscle beyond 28mm:

-deccrease the amount of overlap and increase the amount of tension

-decrease the amount of overlap and not change the amount of tension

-decrease the amount of overlap and decrease the amount of tension produced

-decrease the amount of overlap and decrease the amount of tension produced

At what length do you think this muscle would be able to lift the heaviest weight?

-about 26mm

-about 28

-about 27

-about 29

-about 28

In the intact frog, muscles are held close to their resting length so that maximum tension can be achieved. Excessive shortening and lengthening of the muscle is prevented by

-tendons

-ligaments

-bones and joins

-motor neurons

-bones and joins

maximum tension is acheived when the muscle is at resting length. According to your data the resting length of the muscle was about

-26

-27

-28

-29

-28