PhysioEx Exercise 2 Activity 6
3/6/22, 6:18 PM
PhysioEx Lab Report
Exercise 2: Skeletal Muscle Physiology Activity 6: The Skeletal Muscle Length-Tension Relationship
Name: Zandria
Date: 6 March 2022
Session ID: session-1ca6497f-8e6f-597a-e47f-269f309fd9e6
Pre-Iab Quiz Results
You scored 10o% by answering 5 out of 5 questions correctly
1 During an isometric contraction
You correctly answered: the skeletal muscle is generating force, but it remains at a fixed length.
2 The force that results from muscles being stretched is
You correctly answered: passive force
3 Active force
You correctly answered: is determined by the amount of myosin bound to actin
4 When you generate the isometric length-tension curve, which of the following forces will
not be indicated on your screen?
You correctly answered: tetanic force.
5 Passive force in skeletal muscle is largely caused by
You correctly answered: the protein titin
Experiment Results
Predict Question
1 Predict Question: As the resting length of the muscle is changed, what will happen to the amount of total force the muscle generates during the stimulated twitch?
https://media.pearsoncmg.com/bc/bc_0media_ap/physioex/10/ex2/act6/
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PhysioEx Exercise 2 Activity 6
3/6/22, 6:18 PM
Your answer: Total force can increase or decrease depending upon the starting resting length.
Stop & Think Question
1 Note the dip in total force at a muscle length of 9o mm as compared to the total force at a
muscle length of 80 and 100 mm. Why does this occur?
You correctly answered: At this muscle length, active force has decreased in value and
passive force has not yet increased to a significant value.
Experiment Data
Post-Iab Quiz ResuIts
You scored 80% by answering 4 out of 5 questions correctly.
1 When a skeletal muscle is stimulated and generates force but remains at a fixed length
Your answer: the muscle is contracting isotonically
Correct answer: the muscle is contracting isometrically
2 Which protein is mostly responsible for the development of passive force in a muscle?
You correctly answered: titin.
3 In skeletal muscle, active force stimulated through a range of muscle lengths
You correctly answered: will utilize ATP hydrolysis to drive the cross bridge cycle
4 Which of the following is not depicted in a typical skeletal muscle isometric length-tensior
curve?
You correctly answered: time
5 Maximal active tension will be produced in a skeletal muscle fiber when
You correctly answered: the fiber is at its resting length
Review Sheet Results
1 What happens to the amount of total force the muscle generates during the stimulated twitch? How well did the results compare with your prediction?
https://media.pearsoncmg.com/bc/bc_0media_ap/physioex/10/ex2/act6/
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PhysioEx Exercise 2 Activity 6
3/6/22, 6:18 PM
Your answer:
My predictions was correct, when there is an increase to muscle length, the total force increases. where there is a decrease to muscle length, there is a deceased in total force.
2 What is the key variable in an isometric contraction of a skeletal muscle?
Your answer:
the length- tension relationship
explain why active force varies with changes in the muscle's resting length
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