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APHY 201 - Advanced Human Physiology:
Exam 3 Questions and Correct Answers/
Latest Update / Already Graded
With an elongated shape and the presence of multiple nuclei, a
skeletal muscle cell is also referred to as a ____.
Ans: muscle fiber
Muscle filaments are part of cylindrical bundles called _____ which
extend from one end of the fiber to the other, linked to tendons.
Ans: myofibrils
_____ are composed almost entirely of the protein myosin.
Ans: thick filaments
A repeating pattern of thick and thin filaments is known as a ______.
Ans: sarcomere
The tail of each myosin molecule lies along the axis of the thick
filament, and the two globular heads extend out to the sides, forming
______.
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Ans: cross-bridges
Thin filaments are principally composed of the protein ______, as well
as two other proteins: ______ & _____.
Ans: actin; troponin & tropomyosin
Each actin molecule contains a binding site for ________.
Ans: myosin
Each thick filament cross-bridge contains a binding site for ____ and
_____.
Ans: the thin filament and ATP
Overlapping thick and thin filaments in each sarcomere moving past
each other, propelled by movements of the cross-bridges describes the
______.
Ans: Sliding Filament Mechanism
_____ moves the tropomyosin away, allowing myosin to interact with
the actin.
Ans: Troponin
All rights reserved © 2025/ 2026 |
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By binding troponin with _____, the tropomyosin moves away allowing
the cross-bridge to interact with the actin.
Ans: Ca+
The molecules that partially cover the myosin-binding site on each
actin monomer, thereby preventing the cross-bridges from making
contact with actin are known as _____.
Ans: tropomyosin
Similar to organelles found in most cells, the _______ forms a series of
sleevelike segments around each myofibril.
Ans: sarcoplasmic reticulum
The plasma membrane of the skeletal muscle fiber is known as
_______.
Ans: sarcolemma
Cardiac and smooth muscle cells generally have a single _____, but
skeletal muscle fibers are ________.
Ans: multinucleated
All rights reserved © 2025/ 2026 |
, Page |4
The cytoplasm of striated muscle cells is known as _____.
Ans: sarcoplasm
The activation of the force-generating sites within the cross- bridges is
known as ______.
Ans: contraction
When the mechanisms that generate force are turned off and tension
declines, this allows for _____ of muscle fibers.
Ans: relaxation
A motor neuron plus the muscle fibers it innervates is called a _____.
Ans: motor unit
The neurons whose axons innervate skeletal muscle fibers are known
as ______.
Ans: motor neurons
All rights reserved © 2025/ 2026 |
APHY 201 - Advanced Human Physiology:
Exam 3 Questions and Correct Answers/
Latest Update / Already Graded
With an elongated shape and the presence of multiple nuclei, a
skeletal muscle cell is also referred to as a ____.
Ans: muscle fiber
Muscle filaments are part of cylindrical bundles called _____ which
extend from one end of the fiber to the other, linked to tendons.
Ans: myofibrils
_____ are composed almost entirely of the protein myosin.
Ans: thick filaments
A repeating pattern of thick and thin filaments is known as a ______.
Ans: sarcomere
The tail of each myosin molecule lies along the axis of the thick
filament, and the two globular heads extend out to the sides, forming
______.
All rights reserved © 2025/ 2026 |
, Page |2
Ans: cross-bridges
Thin filaments are principally composed of the protein ______, as well
as two other proteins: ______ & _____.
Ans: actin; troponin & tropomyosin
Each actin molecule contains a binding site for ________.
Ans: myosin
Each thick filament cross-bridge contains a binding site for ____ and
_____.
Ans: the thin filament and ATP
Overlapping thick and thin filaments in each sarcomere moving past
each other, propelled by movements of the cross-bridges describes the
______.
Ans: Sliding Filament Mechanism
_____ moves the tropomyosin away, allowing myosin to interact with
the actin.
Ans: Troponin
All rights reserved © 2025/ 2026 |
, Page |3
By binding troponin with _____, the tropomyosin moves away allowing
the cross-bridge to interact with the actin.
Ans: Ca+
The molecules that partially cover the myosin-binding site on each
actin monomer, thereby preventing the cross-bridges from making
contact with actin are known as _____.
Ans: tropomyosin
Similar to organelles found in most cells, the _______ forms a series of
sleevelike segments around each myofibril.
Ans: sarcoplasmic reticulum
The plasma membrane of the skeletal muscle fiber is known as
_______.
Ans: sarcolemma
Cardiac and smooth muscle cells generally have a single _____, but
skeletal muscle fibers are ________.
Ans: multinucleated
All rights reserved © 2025/ 2026 |
, Page |4
The cytoplasm of striated muscle cells is known as _____.
Ans: sarcoplasm
The activation of the force-generating sites within the cross- bridges is
known as ______.
Ans: contraction
When the mechanisms that generate force are turned off and tension
declines, this allows for _____ of muscle fibers.
Ans: relaxation
A motor neuron plus the muscle fibers it innervates is called a _____.
Ans: motor unit
The neurons whose axons innervate skeletal muscle fibers are known
as ______.
Ans: motor neurons
All rights reserved © 2025/ 2026 |
