Question 1

Which of the following statements concerning smooth muscle is true?

Accepted Answer

A)   It contains many sarcomeres.
B)   Caveolae seem to take the place of the myofibrils.
C)   A calcium-calmodulin complex initiates cross-bridge formation.
D)   The cells are large and multinuclear.
E)   It has a well developed sarcoplasmic reticulum.F) B) and C)
G) B) and D)

Question 2

Tetanus of a muscle is thought to be caused by

Accepted Answer

A)   high calcium ion concentrations in the sarcoplasm.
B)   the rapid movement of sodium ions back into the sarcoplasmic reticulum.
C)   an increase in stimulus strength.
D)   increased temperature in the active muscle.
E)   decreased amounts of calcium ions in muscle tissue.F) A) and B)
G) C) and E)

Question 3

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) B) and D)
G) A) and E)

Question 4

The capacity of a muscle cell to shorten forcefully is known as

Accepted Answer

A)   contractility.
B)   excitability.
C)   extensibility.
D)   elasticity.
E)   flexibility.F) A) and C)
G) None of the above

Question 5

Lack of acetylcholinesterase in the synaptic cleft would result in

Accepted Answer

A)   a decrease in acetylcholine production by the motor neuron.
B)   continuous stimulation of the postsynaptic membrane.
C)   rapid degradation of acetylcholine.
D)   relaxation of the muscle.
E)   continuous stimulation of the presynaptic membrane.F) None of the above
G) A) and E)

Question 6

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) A) and E)

Question 7

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

Question 8

Which of the following connective tissue layers is outside all the others?

Accepted Answer

A)   perimysium
B)   endomysium
C)   epimysium
D)   paramysium
E)   sarcolemmaF) None of the above
G) A) and E)

Question 9

The sites where a chemical substance is transmitted from the presynaptic terminal of an axon to the postsynaptic membrane of a muscle fiber are called

Accepted Answer

A)   neuromuscular junctions.
B)   sarcomeres.
C)   myofilaments.
D)   Z disks.
E)   cell body of neuron.F) A) and C)
G) A) and B)

Question 10

List the following structures in order from smallest to largest. (1)  muscle fiber
(2)  myofilament
(3)  myofibril
(4)  muscle fasciculus

Accepted Answer

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

Question 11

The sarcolemma 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 D)
G) A) and E)

Question 12

The length of the resting sarcomere is

Accepted Answer

A)   longer than the length of a contracted sarcomere.
B)   shorter than the length of a contracted sarcomere.
C)   the same length as a contracted sarcomere.
D)   the same length as the muscle fiber.
E)   the same length as the myofibril.F) A) and B)
G) B) and E)

Question 13

-What does "D" represent on the diagram?

Accepted Answer

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

Question 14

Which of the following correctly describes myoglobin's special function in muscle tissue?

Accepted Answer

A)   breaks down glycogen
B)   synthesizes ATP
C)   acts as a reservoir for oxygen
D)   produces action potentials
E)   stores glucoseF) B) and E)
G) None of the above

Question 15

In a contracted muscle, the A bands do narrow because the length of the myosin myofilaments changes,.

Accepted Answer

A) True 
 B)False

Question 16

In excitation-contraction coupling,

Accepted Answer

A)   calcium ions must bind with myosin to expose active sites on actin.
B)   myosin heads bind to exposed active sites on actin.
C)   cross-bridges form between myosin heads and calcium ions.
D)   movement of the troponin-tropomyosin complex causes actin myofilaments to slide.
E)   ATP binds to actin myofilaments.F) A) and B)
G) A) and E)

Question 17

A lack of mitochondria within skeletal muscle would impair which ATP-yielding chemical process?

Accepted Answer

A)   anaerobic respiration
B)   aerobic respiration
C)   both anaerobic and aerobic respirationD) All of the above
E) A) and B)

Question 18

Increased strength of a trained muscle is due to

Accepted Answer

A)   an increased number of muscle fibers.
B)   the nervous system's ability to recruit a large number of motor units simultaneously.
C)   elimination of unnecessary enzymes and metabolic pathways.
D)   elimination of all fat deposits.
E)   elimination of unnecessary connective tissue.F) C) and D)
G) A) and E)

Question 19

The condition of painful, spasmodic contractions of muscles is referred to as

Accepted Answer

A)   cramps.
B)   fibrositis.
C)   fibromyalgia.
D)   muscular dystrophy.
E)   paralysis.F) B) and E)
G) B) and C)

Question 20

Identify the statement concerning skeletal muscle that is true.

Accepted Answer

A)   It comprises about 20% of the body's weight.
B)   It propels urine through the urinary tract.
C)   Its function is largely under involuntary control.
D)   It is a kind of connective tissue.
E)   It is responsible for locomotion.F) C) and D)
G) B) and C)

Exam 9: Muscular System: Histology and Physiology

One cause of spastic paralysis might be

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The length of the resting sarcomere is

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Which of the following statements concerning smooth muscle is true?

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Increased strength of a trained muscle is due to

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The capacity of a muscle cell to shorten forcefully is known as

Correct AnswerverifiedShow Answer

-What does "D" represent on the diagram?

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The sites where a chemical substance is transmitted from the presynaptic terminal of an axon to the postsynaptic membrane of a muscle fiber are called

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The sarcolemma is the

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Which of the following correctly describes myoglobin's special function in muscle tissue?

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Physiological contracture

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In excitation-contraction coupling,

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Which of the following connective tissue layers is outside all the others?

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Lack of acetylcholinesterase in the synaptic cleft would result in

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List the following structures in order from smallest to largest. (1) muscle fiber (2) myofilament (3) myofibril (4) muscle fasciculus

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In a contracted muscle, the A bands do narrow because the length of the myosin myofilaments changes,.

Correct AnswerverifiedShow Answer

The condition of painful, spasmodic contractions of muscles is referred to as

Correct AnswerverifiedShow Answer

Identify the statement concerning skeletal muscle that is true.

Correct AnswerverifiedShow Answer

A lack of mitochondria within skeletal muscle would impair which ATP-yielding chemical process?

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

Correct AnswerverifiedShow Answer

Tetanus of a muscle is thought to be caused by

Correct AnswerverifiedShow Answer

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