Question 1

Which of the following changes have the potential to dramatically affect the potential difference across the plasma membrane?

Accepted Answer

A)  increased permeability of the membrane to sodium ions
B)  increased intracellular concentration of potassium ions
C)  any change in the rate at which the sodium-potassium pump works
D)  increased permeability of the membrane to sodium ions and increased intracellular concentration of potassium ions
E)  increased permeability of the membrane to sodium ions,increased intracellular concentration of potassium ions and any change in the rate at which the sodium-potassium pump worksF) B) and C)
G) B) and E)

Question 2

The plasma membrane of an excitable cell is more permeable to potassium ions because

Accepted Answer

A)  of its positive electrical charge.
B)  there are more leak ion channels for K+ than Na+.
C)  protein molecules cannot exit through the cell membrane.
D)  calcium ions block Na+ and Cl- channels.
E)  there are more gated channels for K+.F) B) and D)
G) C) and E)

Question 3

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

Accepted Answer

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

Question 4

A waste product of anaerobic respiration in muscle cells is

Accepted Answer

A)  uric acid.
B)  hydrochloric acid.
C)  lactic acid.
D)  carbonic acid.
E)  pyruvic acid.F) All of the above
G) None of the above

Question 5

Aerobic exercise

Accepted Answer

A)  increases vascularity of muscle.
B)  develops fatigue-resistant fast-twitch fibers.
C)  can increase the efficiency of slow-twitch fibers.
D)  can increase the number of mitochondria in muscle cells.
E)  All of these choices are correct.F) B) and C)
G) A) and D)

Question 6

Smooth muscle and cardiac muscle are similar in that they both

Accepted Answer

A)  are under involuntary control.
B)  are striated.
C)  are widely distributed in the body.
D)  have multiple nuclei.
E)  are under voluntary control.F) B) and D)
G) A) and B)

Question 7

The electrical properties of cells are the result of

Accepted Answer

A)  ion concentration differences across the plasma membrane.
B)  receptor sites that are present on the plasma membrane.
C)  phosphorylation reactions within the cytoplasm.
D)  phospholipids in the cell membrane.
E)  None of these choices is correct.F) D) and E)
G) B) and E)

Question 8

Which type of muscle tissue has cells that branch?

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) A) and B)

Question 9

Muscle hypertrophy results from increased numbers of

Accepted Answer

A)  myofibrils and sarcomeres.
B)  muscle fibers.
C)  motor units.
D)  muscles.
E)  muscle cells.F) A) and B)
G) All of the above

Question 10

Smooth muscle

Accepted Answer

A)  responds in an all-or-none fashion.
B)  depolarizes when both sodium and calcium ions diffuse into the cell.
C)  has fast waves of depolarization.
D)  has fast waves of repolarization.
E)  has a resting membrane potential that is more negative than skeletal muscle fibers.F) C) and D)
G) C) and E)

Question 11

Actin myofilaments

Accepted Answer

A)  resemble bundles of minute golf clubs.
B)  contain both myosin and tropomyosin.
C)  are held in place by the M line.
D)  contain strands of fibrous actin.
E)  are the thickest proteins in muscle.F) C) and D)
G) D) and E)

Question 12

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

Accepted Answer

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

Question 13

When skeletal muscle is producing carbon dioxide and water while making ATP,which chemical processes could be active at this time?

Accepted Answer

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

Question 14

Smooth muscle is regulated by all of the following except

Accepted Answer

A)  the autonomic nervous system.
B)  neurotransmitters.
C)  the somatic nervous system.
D)  hormones.
E)  prostaglandins.F) B) and C)
G) A) and C)

Question 15

Which of the following is NOT a known effect of illegal use of anabolic steroids in large dosages?

Accepted Answer

A)  increased muscle size
B)  kidney damage
C)  diminished testosterone secretion
D)  increased cardiovascular fitness
E)  sterilityF) A) and B)
G) B) and E)

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) B) and C)
G) A) and E)

Question 17

Callie is a world class marathon runner.Which of the descriptions about her dominant type of skeletal muscle is FALSE?

Accepted Answer

A)  They split ATP slowly.
B)  They have large deposits of myoglobin.
C)  They are well adapted to anaerobic activity.
D)  They have a well developed blood supply.
E)  They have low glycogen stores.F) None of the above
G) A) and E)

Question 18

If sodium ions cannot enter a muscle fiber in response to a stimulus,

Accepted Answer

A)  contraction cannot occur.
B)  relaxation cannot occur.
C)  sodium ions will be released from the sarcoplasmic reticulum instead.
D)  the active sites are left exposed.
E)  the action potential travels into the muscle anyway.F) A) and D)
G) All of the above

Question 19

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

Accepted Answer

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

Question 20

Which of the following is true about skeletal muscle?

Accepted Answer

A)  Sensory neurons stimulate muscles to contract.
B)  There are very few blood vessels in skeletal muscle.
C)  Every muscle fiber receives a branch of an axon from the nerve.
D)  There are very few nerve fibers in a muscle.
E)  All of these are true.F) A) and D)
G) C) and D)

Exam 9: Muscular System: Histology and Physiology

If sodium ions cannot enter a muscle fiber in response to a stimulus,

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Which of the following is true about skeletal muscle?

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The plasma membrane of an excitable cell is more permeable to potassium ions because

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Actin myofilaments

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Which of the following changes have the potential to dramatically affect the potential difference across the plasma membrane?

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In excitation-contraction coupling,

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Muscle hypertrophy results from increased numbers of

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Smooth muscle

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The electrical properties of cells are the result of

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Which type of muscle tissue has cells that branch?

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A waste product of anaerobic respiration in muscle cells is

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Aerobic exercise

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Which of the following is NOT a known effect of illegal use of anabolic steroids in large dosages?

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Smooth muscle and cardiac muscle are similar in that they both

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When skeletal muscle is producing carbon dioxide and water while making ATP,which chemical processes could be active at this time?

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

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Callie is a world class marathon runner.Which of the descriptions about her dominant type of skeletal muscle is FALSE?

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Smooth muscle is regulated by all of the following except

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

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

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