Question 1

Which of the following is composed of myosin molecules?

Accepted Answer

A)   thick myofilaments
B)   I Bands
C)   Z disks
D)   sarcolemma
E)   tropomyosinF) B) and D)
G) C) and E)

Question 2

Tetanus of muscles is described as

Accepted Answer

A)   action potential frequency is high enough that no relaxation of muscle fibers occurs.
B)   a muscle produces constant tension during contraction.
C)   a muscle produces an increasing tension during contraction.
D)   a muscle produces increasing tension as it shortens.
E)   a muscle produces tension, but the length of the muscle is increasing.F) B) and E)
G) None of the above

Question 3

The diffusion of calcium ions into a smooth muscle cell does not depolarize the membrane so no action potential occurs.

Accepted Answer

A) True 
 B)False

Question 4

A myofilament is the

Accepted Answer

A)   cell membrane of a muscle fiber.
B)   cytoplasm of muscle cells.
C)   structural and functional unit of the skeletal muscle cell.
D)   contractile thread that extends the length of the muscle fiber.
E)   protein strand composed of actin or myosin.F) C) and D)
G) A) and C)

Question 5

ATPase is found in

Accepted Answer

A)   F-actin strands.
B)   G-actin globular units.
C)   myosin heads.
D)   tropomyosin grooves.
E)   troponin molecules.F) B) and C)
G) C) and D)

Question 6

-What does "A" represent on the diagram?

Accepted Answer

A)   myosin myofilament
B)   actin myofilament
C)   sarcomere
D)   Z disk
E)   cross-bridgeF) B) and C)
G) A) and E)

Question 7

T tubules

Accepted Answer

A)   provide nutrients to the muscle fiber.
B)   generate new muscle fibers.
C)   conduct action potentials deep into the muscle cell.
D)   release acetylcholine.
E)   store calcium ions.F) B) and E)
G) B) and C)

Question 8

One cause of spastic paralysis might be

Accepted Answer

A)   inhibition of acetylcholine molecules.
B)   blockage of acetylcholine receptors.
C)   inhibition of acetylcholinesterase.
D)   destruction of synaptic vesicles.
E)   increase in the amount of acetylcholinesterase.F) A) and C)
G) A) and D)

Question 9

Muscle hypertrophy results from increased numbers of

Accepted Answer

A)   myofibrils and sarcomeres.
B)   muscle fibers.
C)   motor units.
D)   muscles.
E)   muscle cells.F) D) and E)
G) None of the above

Question 10

A concentric contraction is described as

Accepted Answer

A)   action potential frequency is high enough that no relaxation of muscle fibers occurs.
B)   a muscle produces constant tension during contraction.
C)   a muscle produces an increasing tension during contraction.
D)   a muscle produces increasing tension as it shortens.
E)   a muscle produces tension, but the length of the muscle is increasing.F) B) and D)
G) D) and E)

Question 11

-The figure illustrates the neuromuscular junction. What does "C" represent?

Accepted Answer

A)   presynaptic terminal
B)   muscle fiber
C)   neuromuscular junction
D)   axon branch
E)   myofibrilsF) C) and D)
G) A) and B)

Question 12

An isotonic contraction is described as

Accepted Answer

A)   action potential frequency is high enough that no relaxation of muscle fibers occurs.
B)   a muscle produces constant tension during contraction.
C)   a muscle produces an increasing tension during contraction.
D)   a muscle produces increasing tension as it shortens.
E)   a muscle produces tension, but the length of the muscle is increasing.F) A) and B)
G) A) and C)

Question 13

-What does "C" represent on the diagram?

Accepted Answer

A)   myosin myofilament
B)   actin myofilament
C)   sarcomere
D)   Z disk
E)   cross-bridgeF) D) and E)
G) A) and B)

Question 14

Channels that open or close in response to changes in the electrical charge or voltage across the plasma membrane are called

Accepted Answer

A)   ligand-gated ion channels.
B)   leak ion channels.
C)   relegated ion channels.
D)   voltage-gated ion channels.
E)   obligated ion channels.F) D) and E)
G) A) and E)

Question 15

-What does "E" represent on the diagram?

Accepted Answer

A)   myosin myofilament
B)   actin myofilament
C)   sarcomere
D)   Z disk
E)   cross-bridgeF) A) and B)
G) None of the above

Question 16

One ATP molecule is required for

Accepted Answer

A)   formation of the cross-bridge.
B)   movement of the cross-bridge.
C)   release of the cross-bridge.
D)   formation of the cross-bridge and for movement of the cross-bridge.
E)   formation of the cross-bridge, for movement of the cross-bridge, and for release of the cross-bridge.F) A) and C)
G) A) and E)

Question 17

Smooth muscle

Accepted Answer

A)   responds in an all-or-none fashion.
B)   depolarizes when both sodium and calcium ions diffuse into the cell.
C)   has fast waves of depolarization.
D)   has fast waves of repolarization.
E)   has a resting membrane potential that is more negative than skeletal muscle fibers.F) A) and E)
G) A) and B)

Question 18

Myosin is also known as the

Accepted Answer

A)   thick myofilament.
B)   thin myofilament.
C)   intermediate myofilament.
D)   short myofilament.
E)   sarcomere.F) A) and B)
G) B) and C)

Question 19

Depolarization of the cell membrane occurs when there is a rapid influx (inflow)  of

Accepted Answer

A)   potassium ions.
B)   chloride ions.
C)   calcium ions.
D)   sodium ions.
E)   amino acids.F) None of the above
G) C) and D)

Question 20

-The figure illustrates a detailed drawing of the neuromuscular junction. What does "D" represent?

Accepted Answer

A)   synaptic vesicles
B)   synaptic cleft
C)   sarcolemma
D)   presynaptic terminal
E)   postsynaptic membraneF) None of the above
G) B) and C)

Exam 9: Muscular System: Histology and Physiology

Which of the following is composed of myosin molecules?

Correct AnswerverifiedShow Answer

A concentric contraction is described as

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-What does "C" represent on the diagram?

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An isotonic contraction is described as

Correct AnswerverifiedShow Answer

Muscle hypertrophy results from increased numbers of

Correct AnswerverifiedShow Answer

-What does "E" represent on the diagram?

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ATPase is found in

Correct AnswerverifiedShow Answer

A myofilament is the

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-What does "A" represent on the diagram?

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Channels that open or close in response to changes in the electrical charge or voltage across the plasma membrane are called

Correct AnswerverifiedShow Answer

Smooth muscle

Correct AnswerverifiedShow Answer

One cause of spastic paralysis might be

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The diffusion of calcium ions into a smooth muscle cell does not depolarize the membrane so no action potential occurs.

Correct AnswerverifiedShow Answer

T tubules

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Depolarization of the cell membrane occurs when there is a rapid influx (inflow) of

Correct AnswerverifiedShow Answer

-The figure illustrates the neuromuscular junction. What does "C" represent?

Correct AnswerverifiedShow Answer

Tetanus of muscles is described as

Correct AnswerverifiedShow Answer

One ATP molecule is required for

Correct AnswerverifiedShow Answer

Myosin is also known as the

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-The figure illustrates a detailed drawing of the neuromuscular junction. What does "D" represent?

Correct AnswerverifiedShow Answer

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