Question 1

Which of the following statements concerning fast-twitch muscle fibers is true?

Accepted Answer

A)  They split ATP rapidly.
B)  They have large deposits of myoglobin.
C)  They are well adapted to aerobic metabolism.
D)  They have a well-developed blood supply.
E)  They have many mitochondria.F) A) and D)
G) A) and C)

Question 2

Muscular dystrophy is characterized by

Accepted Answer

A)  chronic muscle pain.
B)  decreased size of muscle fibers.
C)  spastic contractions of muscles.
D)  replacement of muscle cells by connective tissue.
E)  hypertrophy of muscle tissue.F) A) and B)
G) C) and E)

Question 3

Alex is participating in a 50 meter dash.Predict the most important chemical process his muscles will rely on during this race.

Accepted Answer

A)  aerobic respiration.
B)  anaerobic respiration.
C)  creatine phosphate breakdown.
D)  nuclear reactions.
E)  both anaerobic respiration and creatine phosphate breakdown.F) C) and D)
G) B) and D) E

Question 4

The type of muscle fatigue known as "psychological fatigue" is the result of

Accepted Answer

A)  depleted ATP reserves.
B)  increased calcium ion concentration in the sarcoplasm.
C)  decreased levels of acetylcholine.
D)  the emotional state of an individual.
E)  None of these choices is correct.F) D) and E)
G) A) and E)

Question 5

Troponin

Accepted Answer

A)  has two subunits.
B)  is part of the myosin myofilament.
C)  is a long,flexible protein.
D)  has a calcium-binding site.
E)  binds to ATP.F) D) and E)
G) A) and D)

Question 6

Which type of muscle tissue possesses striations?

Accepted Answer

A)  skeletal muscle
B)  smooth muscle
C)  cardiac muscle
D)  both skeletal and cardiac muscle
E)  both cardiac and smooth muscleF) A) and D)
G) B) and E) D

Question 7

-What does "C" represent on the diagram?

Accepted Answer

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

Question 8

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) All of the above
G) C) and D) B

Question 9

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) A) and D)
G) C) and D)

Question 10

Treppe

Accepted Answer

A)  can contribute to improved muscle efficiency.
B)  may be due to an increase in the level of calcium ions around the myofibril.
C)  is an example of a graded response.
D)  is achieved during warm-up exercises.
E)  All of these choices are correct.F) D) and E)
G) B) and D)

Question 11

Physiological contracture

Accepted Answer

A)  occurs when muscles are resting.
B)  is a condition in which cross-bridges cannot release.
C)  is caused by an abundance of ATP in muscle fibers.
D)  results when muscles are well exercised.
E)  results when the neurotransmitter remains in the receptor.F) B) and C)
G) B) and E)

Question 12

-What does "D" represent on the diagram?

Accepted Answer

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

Question 13

Which type of muscle tissue causes contraction of the heart?

Accepted Answer

A)  skeletal muscle
B)  smooth muscle
C)  cardiac muscleD) A) and B)
E) A) and C)

Question 14

-What does "B" 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 D)

Question 15

What is the role of myosin phosphatase?

Accepted Answer

A)  can rapidly develop action potentials
B)  shallow invaginations of cell membrane
C)  relatively constant tension maintained for a period of time
D)  intracellular cytoskeleton
E)  enzyme that removes phosphate from myosinF) B) and C)
G) A) and E)

Question 16

Skeletal muscle fibers

Accepted Answer

A)  possess striations.
B)  can contract but are not extensible or excitable.
C)  do not require nerve innervation to contract.
D)  increase dramatically in number after birth.
E)  are found in the walls of the stomach.F) A) and B)
G) B) and E)

Question 17

During resting conditions,_________ is synthesized to store energy?

Accepted Answer

A)  calcium
B)  creatine phosphate
C)  creatine
D)  lactic acid
E)  pyruvic acidF) A) and B)
G) D) and E)

Question 18

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

Question 19

Synaptic vesicles in the neuromuscular junction contain

Accepted Answer

A)  calcium.
B)  ATP.
C)  acetylcholine.
D)  acetylcholinesterase.
E)  sodium.F) None of the above
G) A) and B)

Question 20

Which of the following is true?

Accepted Answer

A)  Muscle fatigue has no influence on the force of contractions.
B)  A threshold stimulus will cause contraction of a muscle fiber.
C)  A subthreshold stimulus causes a muscle contraction.
D)  Motor units do not obey the "all or none" law.
E)  A threshold stimulus will not affect motor units.F) A) and C)
G) D) and E)

Exam 9: Muscular System: Histology and Physiology

Which of the following statements concerning fast-twitch muscle fibers is true?

Correct AnswerverifiedShow Answer

Muscular dystrophy is characterized by

Correct AnswerverifiedShow Answer

Alex is participating in a 50 meter dash.Predict the most important chemical process his muscles will rely on during this race.

Correct AnswerverifiedE

The type of muscle fatigue known as "psychological fatigue" is the result of

Correct AnswerverifiedShow Answer

Troponin

Correct AnswerverifiedShow Answer

Which type of muscle tissue possesses striations?

Correct AnswerverifiedD

-What does "C" represent on the diagram?

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

Correct AnswerverifiedB

ATPase is found in

Correct AnswerverifiedShow Answer

Treppe

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Physiological contracture

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-What does "D" represent on the diagram?

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Which type of muscle tissue causes contraction of the heart?

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-What does "B" represent on the diagram?

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What is the role of myosin phosphatase?

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Skeletal muscle fibers

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During resting conditions,_________ is synthesized to store energy?

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Sarcoplasm is the

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Synaptic vesicles in the neuromuscular junction contain

Correct AnswerverifiedShow Answer

Which of the following is true?

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E

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D

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B

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