Question 1

An isometric 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 as the length remains constant.
D)  a muscle produces increasing tension as it shortens.
E)  a muscle produces tension,but the length of the muscle is increasing.F) C) and E)
G) A) and C)

Question 2

A sarcomere extends from

Accepted Answer

A)  one Z disk to an adjacent Z disk.
B)  one T tubule to the next T tubule.
C)  the middle of the I band to the middle of the A band.
D)  the H zone to the I band.
E)  the M line to the next M line.F) B) and E)
G) All of the above

Question 3

In smooth muscle,cross-bridging occurs due to

Accepted Answer

A)  calcium binding to troponin.
B)  calcium binding to calmodulin.
C)  myosin kinase adding a phosphate to myosin heads.
D)  both calcium binding to troponin and calmodulin.
E)  both calcium binding to calmodulin and myosin kinase adding a phosphate to myosin heads.F) A) and E)
G) A) and D)

Question 4

An antibody test on smooth muscle reveals fewer dense bodies and intermediate filaments in a patient with a colon disorder.What is the purpose of these structures?

Accepted Answer

A)   can rapidly develop action potentials in smooth muscle cells
B)  shallow invaginations of cell membrane
C)   maintain relatively constant tension in smooth muscle for a period of time
D)   part of the intracellular cytoskeleton
E)   act as enzymes that remove phosphate from myosinF) A) and B)
G) A) and C)

Question 5

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 D)
G) A) and E)

Question 6

When an action potential reaches the presynaptic terminal,

Accepted Answer

A)  calcium ions diffuse into the presynaptic terminal through voltage-gated ion channels.
B)  acetylcholine moves into the presynaptic terminal.
C)  a local potential is generated in the presynaptic terminal.
D)  ligand-gated ion channels in the presynaptic terminal are opened.
E)  nothing else happens.F) B) and E)
G) None of the above

Question 7

Select the term that does not belong with the others.

Accepted Answer

A)  muscle atrophy
B)  immobilization
C)  decrease in number of myofibrils
D)  loss of nerve stimulation
E)  increased vascularityF) A) and E)
G) C) and E)

Question 8

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) None of the above
G) B) and E)

Question 9

Visceral smooth muscle

Accepted Answer

A)  may contain groups of cells that function as an independent unit.
B)  occurs in sheets and exhibits numerous gap junctions.
C)  contracts only when stimulated.
D)  does not function as a unit.
E)  All of these choices are correct.F) None of the above
G) A) and B)

Question 10

A condition in which stimuli occur so rapidly that there are no intervening relaxations between contractions is called

Accepted Answer

A)  complete tetanus.
B)  incomplete tetanus.
C)  involuntary paralysis.
D)  all or none tetanus.
E)  treppe.F) B) and E)
G) A) and D)

Question 11

Which of the following statements regarding the sliding filament model is false?

Accepted Answer

A)  Actin and myosin do not shorten during contraction.
B)  Both actin and myosin myofilaments shorten during contraction.
C)  The sarcomere shortens.
D)  The I band and H zones become narrower during contraction.
E)  The A band remains constant in length.F) A) and B)
G) A) and C)

Question 12

-The figure illustrates a detailed drawing of the neuromuscular junction.What does "E" represent?

Accepted Answer

A)  synaptic vesicles
B)  synaptic cleft
C)  sarcolemma
D)  presynaptic terminal
E)   postsynaptic membraneF) A) and B)
G) A) and D)

Question 13

-What does "E" represent on the diagram?

Accepted Answer

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

Question 14

Which of the following is composed of myosin molecules?

Accepted Answer

A)  thick myofilaments
B)  I Bands
C)  Z disks
D)  sarcolemma
E)  tropomyosinF) A) and C)
G) C) and E)

Question 15

A proper definition of muscle tone is

Accepted Answer

A)  constant tension produced by muscles for long periods of time.
B)  a feeling of well-being following exercise.
C)  the ability of a muscle to maintain a contraction against an outside force.
D)  muscles contracting together.
E)  warm-up of muscle tissue.F) A) and D)
G) A) and E)

Question 16

Tetanus of muscles 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) B) and C)
G) A) and D)

Question 17

Susan slipped on the ice and was unable to be fully mobile for several days.What disruption to homeostasis would you predict she experienced during her immobile period in terms of her muscular system?

Accepted Answer

A)   Susan's metabolic rate was raised and it initiated sweating.
B)   Susan was more cold than usual because her inactivity prevented her muscles from helping to regulate her body temperature.
C)   Susan's uninjured muscles overcompensate for the inactive ones by contracting spontaneously.D) None of the above
E) All of the above

Question 18

The type of neurotransmitter or hormone that binds to receptors on smooth muscle plasma membranes determines the response of the muscle.

Accepted Answer

A) True 
 B)False

Question 19

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

Question 20

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

Exam 9: Muscular System: Histology and Physiology

Select the term that does not belong with the others.

Correct AnswerverifiedShow Answer

Visceral smooth muscle

Correct AnswerverifiedShow Answer

A proper definition of muscle tone is

Correct AnswerverifiedShow Answer

In smooth muscle,cross-bridging occurs due to

Correct AnswerverifiedShow Answer

An isometric contraction is described as

Correct AnswerverifiedShow Answer

An antibody test on smooth muscle reveals fewer dense bodies and intermediate filaments in a patient with a colon disorder.What is the purpose of these structures?

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

Which of the following statements regarding the sliding filament model is false?

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

Susan slipped on the ice and was unable to be fully mobile for several days.What disruption to homeostasis would you predict she experienced during her immobile period in terms of her muscular system?

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

Which of the following is composed of myosin molecules?

Correct AnswerverifiedShow Answer

A sarcomere extends from

Correct AnswerverifiedShow Answer

Tetanus of muscles is described as

Correct AnswerverifiedShow Answer

When an action potential reaches the presynaptic terminal,

Correct AnswerverifiedShow Answer

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

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-What does "E" represent on the diagram?

Correct AnswerverifiedShow Answer

-The figure illustrates a detailed drawing of the neuromuscular junction.What does "E" represent?

Correct AnswerverifiedShow Answer

A condition in which stimuli occur so rapidly that there are no intervening relaxations between contractions is called

Correct AnswerverifiedShow Answer

The type of neurotransmitter or hormone that binds to receptors on smooth muscle plasma membranes determines the response of the muscle.

Correct AnswerverifiedShow Answer

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