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Chapter12Muscles.
What is the sliding filament theory? Explain the steps of the sliding
filament theory.
Sliding filament theory explains the mechanism of muscle contraction based
on muscle proteins that slide past each other to generate movement.
The steps of sliding filament theory are as follows:
• When Calcium is present the blocked active site of the actin clears.
• Power stroke: myosin head pivots pulling the actin filament toward the
center.
• The cross bridge detaches when a new ATP binds with the myosin.
What is troponin and tropomyosin? What is their role in muscle
contraction?
Troponin is attached to the protein tropomyosin and lies within the groove
between actin filaments in muscle tissue. In a relaxed muscle, tropomyosin
blocks the attachment
site for the myosin crossbridge, thus preventing contraction. The prevent
contraction.
Explain the steps of skeletal muscle contraction, starting at the motor
neuron.
APHY 201 ASSIGNMENTS CHAPTERS 12 TEST
QUESTIONS AND ANSWERS CORRECT/VERIFIED NEW
UPDATE 2022
, APHY 201 ASSIGNMENTS CHAPTERS 12 TEST
QUESTIONS AND ANSWERS CORRECT/VERIFIED NEW
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• A single motor neuron with multiple axon terminals can
innervate multiple muscle fibers, thereby causing all of them to
contract at the same time.
• The connection between a motor neuron axon terminal and a muscle
fiber occurs at a site called a neuromuscular junction.
• This is a chemical synapse where a motor neuron transmits a signal
to a muscle fiber to initiate a muscle contraction.
What are the three types of muscles? How they similar? Different?
Cardiac muscle, Skeletal muscle and Smooth muscle.
They are similar by functions and different by same functions.
What is a myofibril, actin, myosin, z-disk, sarcomere, nebulin, titin,
sarcoplasm reticulum, transverse tubules?
• A myofibril also known as a muscle fibril is a basic rod-like unit of a
muscle cell.
Muscles are composed of tubular cells called myocytes, known as
muscle fibers in striated muscle, and these cells in turn contain many
chains of myofibrils.
• Actin is a family of globular multi-functional proteins that form
APHY 201 ASSIGNMENTS CHAPTERS 12 TEST
QUESTIONS AND ANSWERS CORRECT/VERIFIED NEW
UPDATE 2022