How Muscle Fibers Contract - SLIDING FILAMENT THEORY OF CONTRACTION Flashcards
What is sliding?
Actin slides because myosin heads swing pulling on actin.
What happens when Sarcomeres shorten?
It causes the muscle to shorten.
What is the sequence of events?
a. Crossbridge formation: Myosin heads attach to actin
filaments at the active sites.
b. Myosin hinge regions bend, causing myosin heads to
swing.
c. Swinging of the myosin heads pulls the actin filaments,
sliding them toward each other, toward the center of the
sarcomere.
What are the results in the Sarcomere?
a. Sarcomere length shortens
b. H Zone disappears
c. I Band length shortens
d. A Band length remains same
What is the only thing that does not change?
A Band length remains same
The Sliding Filament Theory explains only one
type of muscle contraction. What is it?
the isotonic contraction, which
causes movement of any body part.
