Question 1

Decreased blood flow to a muscle could result in all of the following except

Accepted Answer

A)  muscle fatigue.
B)  an oxygen debt.
C)  an increase in intracellular glycogen.
D)  a shift to anaerobic glycolysis.
E)  an increase in intracellular lactic acid.F) B) and D)
G) A) and C)

Question 2

At what point during excitation contraction coupling does exocytosis play a role?

Accepted Answer

A)  during calcium ion reuptake into the sarcoplasmic reticulum
B)  when sodium channels open up on the motor end plate
C)  during acetylcholine release from the synaptic terminal
D)  when the action potential surges through the T-tubules
E)  when ATP splits into ADP and P on the free myosin headF) B) and D)
G) A) and D)

Question 3

At rest,the tropomyosin molecule is held in place by

Accepted Answer

A)  actin molecules.
B)  myosin molecules.
C)  troponin molecules.
D)  ATP molecules.
E)  calcium ions.F) A) and B)
G) B) and D)

Question 4

Describe a motor unit.How many fibers does a motor unit contain?

Accepted Answer

A motor unit consists of all o...

Question 5

A fascicle is a

Accepted Answer

A)  group of muscle fibers that are encased in the perimysium.
B)  layer of connective tissue that separates muscle from skin.
C)  group of muscle fibers that are all part of the same motor unit.
D)  group of muscle fibers and motor neurons.
E)  collection of myofibrils in a muscle fiber.F) A) and B)
G) B) and D)

Question 6

Figure 10-1 Skeletal Muscle Fiber
Use Figure 10-1 to answer the following questions:
-Which of the following are found in the structure labeled "3"?

Accepted Answer

A)  actin
B)  myosin
C)  titin
D)  tropomyosin
E)  All of the answers are correct.F) C) and D)
G) A) and D)

Question 7

Identify the incorrect statement about a single motor unit.

Accepted Answer

A)  The more neurons involved,the more powerful the contraction.
B)  The smaller the number of muscle fibers,the more precise the movement.
C)  Fine motor skills depend on the development of small motor units.
D)  Some motor units include as many as 2000 muscle fibers.
E)  Muscle fibers of one motor unit intermingle with the fibers of another motor unit.F) A) and E)
G) A) and D)

Question 8

A single motor neuron together with all the muscle fibers it innervates is called a(n)

Accepted Answer

A)  end foot.
B)  end plate.
C)  motor unit.
D)  dermatome.
E)  myotome.F) None of the above
G) C) and D)

Question 9

If a second stimulus arrives before the relaxation phase has ended,a second,more powerful contraction occurs.This addition of one twitch to another is called

Accepted Answer

A)  incomplete tetanus.
B)  complete tetanus.
C)  treppe.
D)  wave summation.
E)  recruitment.F) A) and C)
G) A) and B)

Question 10

Thick filaments are made of the protein

Accepted Answer

A)  actin.
B)  titin.
C)  myosin.
D)  tropomyosin.
E)  nebulin.F) A) and B)
G) B) and E)

Question 11

Each skeletal muscle fiber contains ________ myofibrils.

Accepted Answer

A)  50 to 100
B)  100 to 150
C)  150 to 200
D)  200 to 500
E)  hundreds to thousandsF) None of the above
G) C) and D)

Question 12

Because skeletal muscle contractions demand large quantities of ATP,skeletal muscles have

Accepted Answer

A)  a rich nerve supply to ensure a rapid succession of action potentials.
B)  massive creatine phosphate reserves for long periods of sustained contractions.
C)  extra calcium reserves which can serve as fuel molecules during ATP synthesis.
D)  adipose tissue between fibers to supply nutrients for ATP production.
E)  many mitochondria and a rich blood supply.F) C) and D)
G) All of the above

Question 13

The action potential is conducted into a skeletal muscle fiber by

Accepted Answer

A)  motor end plates.
B)  neuromuscular junctions.
C)  transverse tubules.
D)  triads.
E)  sarcoplasmic reticulum.F) B) and D)
G) A) and E)

Question 14

Fast fibers

Accepted Answer

A)  have low resistance to fatigue.
B)  rely on aerobic metabolism.
C)  have many mitochondria.
D)  have twitches with a very brief contraction phase.
E)  have low resistance to fatigue and quick twitches.F) A) and B)
G) A) and C)

Question 15

Creatine phosphate

Accepted Answer

A)  is produced by the process of anaerobic respiration.
B)  can replace ATP in binding to myosin molecules during contraction.
C)  acts as an energy reserve in muscle tissue.
D)  is only formed during strenuous exercise.
E)  cannot transfer its phosphate group to ADP.F) B) and E)
G) C) and D)

Question 16

Which of the following best describes the term sarcomere?

Accepted Answer

A)  protein that accounts for elasticity of resting muscle
B)  repeating unit of striated myofibrils
C)  storage site for calcium ions
D)  thin filaments are anchored here
E)  largely made of myosin moleculesF) B) and E)
G) A) and C)

Question 17

Describe the basic sequence of events that occurs as an action potential arrives at the neuromuscular junction and is transmitted to the muscle cell.

Accepted Answer

The action potential triggers the exocyt...

Question 18

Which of the following statements is/are false regarding human muscles?

Accepted Answer

A)  Most have both slow and fast fibers.
B)  Slow fibers are abundant in the muscles of the hand.
C)  Eye muscles are composed entirely of fast fibers.
D)  Slow fibers are abundant in the back muscles.
E)  All of the answers are correct; none of them are true regarding human muscles.F) B) and E)
G) B) and D)

Question 19

All of the following proteins are part of the thin filaments except

Accepted Answer

A)  actin.
B)  tropomyosin.
C)  troponin.
D)  titin.
E)  None of the answers is correct; there are no exceptions.F) B) and C)
G) A) and B)

Question 20

The most important factor in decreasing the intracellular concentration of calcium ion after contraction is

Accepted Answer

A)  active transport of calcium across the sarcolemma.
B)  active transport of calcium into the sarcoplasmic reticulum.
C)  active transport of calcium into the synaptic cleft.
D)  diffusion of calcium out of the cell.
E)  diffusion of calcium into the sarcoplasmic reticulum.F) A) and B)
G) A) and C)

Exam 10: Muscle Tissue

The action potential is conducted into a skeletal muscle fiber by

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Which of the following statements is/are false regarding human muscles?

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Decreased blood flow to a muscle could result in all of the following except

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Each skeletal muscle fiber contains ________ myofibrils.

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If a second stimulus arrives before the relaxation phase has ended,a second,more powerful contraction occurs.This addition of one twitch to another is called

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Describe a motor unit.How many fibers does a motor unit contain?

Correct AnswerverifiedA motor unit consists of all o...View AnswerShow Answer

Creatine phosphate

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Thick filaments are made of the protein

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Fast fibers

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Figure 10-1 Skeletal Muscle Fiber Use Figure 10-1 to answer the following questions: -Which of the following are found in the structure labeled "3"?

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At rest,the tropomyosin molecule is held in place by

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The most important factor in decreasing the intracellular concentration of calcium ion after contraction is

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At what point during excitation contraction coupling does exocytosis play a role?

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A single motor neuron together with all the muscle fibers it innervates is called a(n)

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All of the following proteins are part of the thin filaments except

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Because skeletal muscle contractions demand large quantities of ATP,skeletal muscles have

Correct AnswerverifiedShow Answer

A fascicle is a

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Describe the basic sequence of events that occurs as an action potential arrives at the neuromuscular junction and is transmitted to the muscle cell.

Correct AnswerverifiedThe action potential triggers the exocyt...View AnswerShow Answer

Which of the following best describes the term sarcomere?

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Identify the incorrect statement about a single motor unit.

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A motor unit consists of all o...
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The action potential triggers the exocyt...
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