Question 1

The refractory period

Accepted Answer

A)   is the time during which the tissue cannot respond again.
B)   results in complete and incomplete tetanus.
C)   is the condition in which the muscle fiber only partially relaxes between contractions.
D)   is the condition in which stimuli occur so rapidly that there are no intervening relaxations.
E)   is the constant tension produced by muscles for long periods of time.F) C) and D)
G) B) and E)

Question 2

Multiple wave summation

Accepted Answer

A)   is a time during which the tissue cannot respond again.
B)   results in complete and incomplete tetanus.
C)   is a condition in which the muscle fiber only partially relaxes between contractions.
D)   is a condition in which stimuli occur so rapidly that there are no intervening relaxations.
E)   is a constant tension produced by muscles for long periods of time.F) D) and E)
G) C) and E) B

Question 3

T tubules are invaginations of the

Accepted Answer

A)   sarcoplasmic reticulum.
B)   sarcomere.
C)   myofibril.
D)   sarcoplasm.
E)   sarcolemma.F) D) and E)
G) B) and D)

Question 4

Maureen is hiking in the cold, and to maintain homeostasis her body begins to

Accepted Answer

A)   increase heat loss from the skin.
B)   release chemicals to initiate a high fever.
C)   shiver.
D)   reduce her blood pressure.
E)   vasodilate vessels in her head and neck.F) A) and E)
G) C) and D)

Question 5

Which of the following would occur as a result of a single muscle contraction?

Accepted Answer

A)   tetanus
B)   tone
C)   treppe
D)   twitch
E)   paralysisF) C) and D)
G) A) and B)

Question 6

When comparing smooth and skeletal muscle cells, which of the following statements is true?

Accepted Answer

A)   Smooth muscle cells have striations.
B)   The myofilaments in smooth muscle do not form sarcomeres.
C)   Smooth muscle cells are larger than skeletal muscle cells.
D)   Smooth muscle has a lot of actin and myosin.
E)   Smooth muscle cells are multinucleated.F) A) and B)
G) None of the above

Question 7

Which of the following is mismatched?

Accepted Answer

A)   I band - contains only actin
B)   M line - middle of the H zone
C)   Z disk - structure between adjacent sarcomeres
D)   myosin myofilaments - thin myofilaments
E)   actin myofilaments - thin myofilamentsF) D) and E)
G) A) and B)

Question 8

When the myosin head flexes into a bend, pulling the actin filament along with it, this is called the

Accepted Answer

A)   action reaction.
B)   power stroke.
C)   recovery stroke.
D)   muscle tone.
E)   action potential.F) B) and C)
G) A) and D)

Question 9

A sustained muscle contraction is known as

Accepted Answer

A)   tetanus
B)   tone
C)   treppe
D)   twitch
E)   paralysisF) A) and B)
G) B) and D)

Question 10

A sarcomere 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) A) and B)
G) All of the above

Question 11

-What does "B" represent on the diagram?

Accepted Answer

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

Question 12

What would result from a lack of extracellular calcium ions at the neuromuscular junction?

Accepted Answer

A)   Excessive synaptic vesicles would fuse and release too much ACh, overstimulating the myofiber.
B)   Synaptic vesicles would fail to fuse and ACh would not be released.
C)   Nothing would happen because extracellular calcium does not play a role in muscle stimulation.
D)   The neuron must use its intracellular calcium to make the vesicles fuse.
E)   Potassium ions are used in place of calcium to ensure the vesicles fuse.F) B) and E)
G) C) and D) B

Question 13

Smooth muscle is regulated by all of the following except

Accepted Answer

A)   the autonomic nervous system.
B)   neurotransmitters.
C)   the somatic nervous system.
D)   hormones.
E)   prostaglandins.F) A) and E)
G) B) and C)

Question 14

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) D) and E)
G) C) and D) D

Question 15

Cardiac muscle cells are like skeletal muscle cells in that they both

Accepted Answer

A)   have striations.
B)   depolarize as a result of sodium and calcium influxes.
C)   possess intercalated disks.
D)   lack sarcomeres.
E)   are multinucleated.F) A) and B)
G) D) and E)

Question 16

The outside of the resting plasma membrane is __________ relative to the inside of the resting plasma membrane.

Accepted Answer

A)   positively charged
B)   negatively charged
C)   electrically neutral
D)   recharged
E)   None of these choices is correct.F) A) and D)
G) B) and E)

Question 17

A myofibril 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.F) A) and C)
G) D) and E)

Question 18

Muscle tone

Accepted Answer

A)   is a time during which the tissue cannot respond again.
B)   results in complete and incomplete tetanus.
C)   is a condition in which the muscle fiber only partially relaxes between contractions.
D)   is a condition in which stimuli occur so rapidly that there are no intervening relaxations.
E)   is a constant tension produced by muscles for long periods of time.F) C) and E)
G) B) and C)

Question 19

What type of muscle tissue causes vasoconstriction?

Accepted Answer

A)   skeletal muscle
B)   smooth muscle
C)   cardiac muscleD) B) and C)
E) All of the above

Question 20

An action potential

Accepted Answer

A)   occurs when the local potential reaches threshold level.
B)   is not propagated.
C)   has no repolarization phase.
D)   is an example of negative feedback.
E)   can be of varying strengths depending on strength of the stimulus.F) A) and D)
G) C) and D)

Exam 9: Muscular System: Histology and Physiology

The refractory period

Correct AnswerverifiedShow Answer

Multiple wave summation

Correct AnswerverifiedB

T tubules are invaginations of the

Correct AnswerverifiedShow Answer

Maureen is hiking in the cold, and to maintain homeostasis her body begins to

Correct AnswerverifiedShow Answer

Which of the following would occur as a result of a single muscle contraction?

Correct AnswerverifiedShow Answer

When comparing smooth and skeletal muscle cells, which of the following statements is true?

Correct AnswerverifiedShow Answer

Which of the following is mismatched?

Correct AnswerverifiedShow Answer

When the myosin head flexes into a bend, pulling the actin filament along with it, this is called the

Correct AnswerverifiedShow Answer

A sustained muscle contraction is known as

Correct AnswerverifiedShow Answer

A sarcomere is the

Correct AnswerverifiedShow Answer

-What does "B" represent on the diagram?

Correct AnswerverifiedShow Answer

What would result from a lack of extracellular calcium ions at the neuromuscular junction?

Correct AnswerverifiedB

Smooth muscle is regulated by all of the following except

Correct AnswerverifiedShow Answer

A concentric contraction is described as

Correct AnswerverifiedD

Cardiac muscle cells are like skeletal muscle cells in that they both

Correct AnswerverifiedShow Answer

The outside of the resting plasma membrane is __________ relative to the inside of the resting plasma membrane.

Correct AnswerverifiedShow Answer

A myofibril is the

Correct AnswerverifiedShow Answer

Muscle tone

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What type of muscle tissue causes vasoconstriction?

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An action potential

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B

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B

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D

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