Question 1

________ is composed of multiple globular molecules polymerized to form long chains or filaments.

Accepted Answer

A)   Actin
B)   Tropomyosin
C)   Troponin
D)   Myosin
E)   TitinF) A) and E)
G) B) and D)

Question 2

Which of the following statements is NOT correct regarding the motor units and their activation?

Accepted Answer

A)   A motor unit in muscles of gross movement can have thousands of muscle cells.
B)   All muscle fibers in a single motor unit are of the same fiber type.
C)   A weak contractile stimulus activates fast-twitch motor units.
D)   The metabolic capacity of muscle fibers within a motor unit can be altered.
E)   At its peak intensity, a contractile stimulus will activate muscle fibers that are easily fatigued.F) A) and B)
G) A) and C)

Question 3

Smooth muscle cells of blood vessels are described as integrating centers.Outline the various inputs that affect smooth muscle cells and how those are integrated.

Accepted Answer

Myogenic responses, autonomic neurotrans...

Question 4

A contraction that generates enough force to move a load is known as ________, whereas one that generates force that equals the load is known as ________.

Accepted Answer

A)   isotropic, isometric
B)   isometric, eccentric
C)   isotonic, isometric
D)   isometric, isotonic
E)   isotonic, eccentricF) A) and D)
G) All of the above

Question 5

Myasthenia gravis is a disease characterized by reduction in the number of acetylcholine receptors on skeletal muscles.Which physiological process would be affected? What would someone afflicted by this disease experience? How may this disease be treated?

Accepted Answer

Neuromuscular transmission would be affe...

Question 6

The reductions in muscle force generation at lengths different from optimal are a result of a(n)________.

Accepted Answer

decrease i...

Question 7

The molecular event that occurs immediately after the power stroke is the

Accepted Answer

A)   release of actin from the myosin head.
B)   hydrolysis of ATP by the myosin head.
C)   release of ADP from the myosin.
D)   binding of tropomyosin to the myosin.
E)   binding of actin to the myosin.F) All of the above
G) B) and E)

Question 8

This protein is activated by the Ca²⁺-calmodulin complex to phosphorylate the myosin light chain protein.

Accepted Answer

A)   tropomyosin
B)   myosin heavy chain
C)   myosin light chain kinase
D)   myosin light chain phosphataseE) A) and B)
F) None of the above

Question 9

Match from the following list.
-The band with the most overlap between thick and thin filaments, which unevenly scatters light leading to its' dark appearance.

Accepted Answer

A)  A band
B)  I band
C)  Z disk
D)  H zone
E)  M lineF) A) and B)
G) A) and D)

Question 10

The H zone contains

Accepted Answer

A)   thick filaments.
B)   thin filaments only.
C)   actin only.
D)   thick and thin filaments.E) B) and C)
F) A) and B)

Question 11

For antagonistic muscle groups to move a limb, flexor contraction occurs coincident with

Accepted Answer

A)   contraction of the extensor.
B)   relaxation of the extensor.
C)   no changes in the extensor.
D)   contraction of the tendon.E) B) and D)
F) B) and C)

Question 12

________ is the backup energy molecule that can be rapidly converted to ATP in active skeletal muscle.

Accepted Answer

A)   Protein
B)   Glucose
C)   Fatty acid
D)   PhosphocreatineE) B) and C)
F) A) and D)

Question 13

The force generated by a single muscle fiber can be increased by

Accepted Answer

A)   increasing frequency of action potentials only.
B)   increasing muscle length beyond optimal only.
C)   increasing the asynchrony of recruitment only.
D)   increasing frequency of action potentials and increasing muscle length beyond optimal only.E) All of the above
F) None of the above

Question 14

Put these events in the correct chronological sequence:
1) End-plate potentials trigger action potentials.
2) Transverse tubules convey potentials into the interior of the cell.
3) Acetylcholine binds to receptors on the motor end plate.
4) Ca²⁺ is released from the sarcoplasmic reticulum.

Accepted Answer

A)   1, 2, 3, 4
B)   3, 1, 2, 4
C)   2, 1, 4, 3
D)   3, 1, 4, 2
E)   4, 3, 2, 1F) A) and B)
G) A) and C)

Question 15

Smooth muscle fibers can sustain a contraction without fatigue by allowing dephosphorylated myosin to remain attached to actin in what is called the ________.

Accepted Answer

The answer of Smooth muscle fibers can sustain a contraction...

Question 16

The hydrolysis of ATP causes myosin to immediately

Accepted Answer

A)   swivel, moving the actin molecule.
B)   release ADP.
C)   release from the actin.
D)   rotate into a position (cocked)  to bind to actin.
E)   bind more tightly to the actin (rigor) .F) C) and D)
G) A) and C)

Question 17

Which of the following would cause the crossbridge to transition from a high force state to a low force state?

Accepted Answer

A)   increasing myosin ATPase activity
B)   increasing intracellular calcium
C)   decreasing intracellular calcium
D)   energizing the myosin head
E)   decreasing myosin ATPase activityF) A) and E)
G) B) and D)

Question 18

A flexor is a skeletal muscle whose shortening moves attached bones

Accepted Answer

A)   away from one another.
B)   towards one another.
C)   medially.
D)   laterally.E) A) and D)
F) B) and C)

Question 19

Match the structures with the accurate description.
-inward extensions of the muscle cell membrane

Accepted Answer

A)  muscle fiber
B)  fascicle
C)  sarcolemma
D)  myofibril
E)  t-tubulesF) None of the above
G) A) and B)

Question 20

The tension generated in a skeletal muscle fiber is directly proportional to the number of

Accepted Answer

A)   thick and thin filaments present.
B)   nebulin and titin molecules present.
C)   high-energy crossbridges formed.
D)   low-energy crossbridges formed.
E)   active sarcomeres.F) A) and C)
G) B) and E)

Exam 12: Muscles

________ is composed of multiple globular molecules polymerized to form long chains or filaments.

Correct AnswerverifiedShow Answer

The tension generated in a skeletal muscle fiber is directly proportional to the number of

Correct AnswerverifiedShow Answer

Which of the following would cause the crossbridge to transition from a high force state to a low force state?

Correct AnswerverifiedShow Answer

Smooth muscle cells of blood vessels are described as integrating centers.Outline the various inputs that affect smooth muscle cells and how those are integrated.

Correct AnswerverifiedMyogenic responses, autonomic neurotrans...View AnswerShow Answer

Which of the following statements is NOT correct regarding the motor units and their activation?

Correct AnswerverifiedShow Answer

The H zone contains

Correct AnswerverifiedShow Answer

A contraction that generates enough force to move a load is known as ________, whereas one that generates force that equals the load is known as ________.

Correct AnswerverifiedShow Answer

For antagonistic muscle groups to move a limb, flexor contraction occurs coincident with

Correct AnswerverifiedShow Answer

Myasthenia gravis is a disease characterized by reduction in the number of acetylcholine receptors on skeletal muscles.Which physiological process would be affected? What would someone afflicted by this disease experience? How may this disease be treated?

Correct AnswerverifiedNeuromuscular transmission would be affe...View AnswerShow Answer

The force generated by a single muscle fiber can be increased by

Correct AnswerverifiedShow Answer

Put these events in the correct chronological sequence: 1) End-plate potentials trigger action potentials. 2) Transverse tubules convey potentials into the interior of the cell. 3) Acetylcholine binds to receptors on the motor end plate. 4) Ca²⁺ is released from the sarcoplasmic reticulum.

Correct AnswerverifiedShow Answer

The hydrolysis of ATP causes myosin to immediately

Correct AnswerverifiedShow Answer

Smooth muscle fibers can sustain a contraction without fatigue by allowing dephosphorylated myosin to remain attached to actin in what is called the ________.

Correct AnswerverifiedShow Answer

A flexor is a skeletal muscle whose shortening moves attached bones

Correct AnswerverifiedShow Answer

________ is the backup energy molecule that can be rapidly converted to ATP in active skeletal muscle.

Correct AnswerverifiedShow Answer

The molecular event that occurs immediately after the power stroke is the

Correct AnswerverifiedShow Answer

The reductions in muscle force generation at lengths different from optimal are a result of a(n)________.

Correct Answerverifieddecrease i...View AnswerShow Answer

Match from the following list. -The band with the most overlap between thick and thin filaments, which unevenly scatters light leading to its' dark appearance.

Correct AnswerverifiedShow Answer

Match the structures with the accurate description. -inward extensions of the muscle cell membrane

Correct AnswerverifiedShow Answer

This protein is activated by the Ca²⁺-calmodulin complex to phosphorylate the myosin light chain protein.

Correct AnswerverifiedShow Answer

Correct Answer
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Myogenic responses, autonomic neurotrans...
View Answer

Correct Answer
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Correct Answer
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A contraction that generates enough force to move a load is known as , whereas one that generates force that equals the load is known as .

Correct Answer
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Correct Answer
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Correct Answer
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Neuromuscular transmission would be affe...
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decrease i...
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