Question 1

Alex is participating in a 50 meter dash. Predict the most important chemical process his muscles will rely on during this race.

Accepted Answer

A)   aerobic respiration.
B)   anaerobic respiration.
C)   creatine phosphate breakdown.
D)   nuclear reactions.
E)   both anaerobic respiration and creatine phosphate breakdown.F) A) and B)
G) A) and C)

Question 2

What is the role of pacemaker cells?

Accepted Answer

A)   can rapidly develop action potentials
B)   shallow invaginations of cell membrane
C)   relatively constant tension maintained for a period of time
D)   intracellular cytoskeleton
E)   enzyme that removes phosphate from myosinF) A) and C)
G) B) and D)

Question 3

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

Question 4

Which of the following statements concerning fast-twitch muscle fibers is true?

Accepted Answer

A)   They split ATP rapidly.
B)   They have large deposits of myoglobin.
C)   They are well adapted to aerobic metabolism.
D)   They have a well-developed blood supply.
E)   They have many mitochondria.F) A) and B)
G) A) and C)

Question 5

A child ingested an organophosphate poison used to kill insects. Soon the child's muscles began spastic contractions. Predict what occurred at the synaptic cleft.

Accepted Answer

A)   decreased release of acetylcholine from presynaptic neurons
B)   increased accumulation of acetylcholine in the synapse
C)   the poison binds to acetylcholine receptors and stimulates them
D)   increased breakdown of acetylcholine in the synaptic cleft
E)   Both increased accumulation of acetylcholine in the synapse and increased breakdown of acetylcholine in the synaptic cleft.F) A) and B)
G) A) and C)

Question 6

Which type of muscle tissue would cause flexion and extension of the arm?

Accepted Answer

A)   skeletal muscle
B)   smooth muscle
C)   cardiac muscleD) A) and C)
E) None of the above

Question 7

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

Question 8

Muscles exhibit the property of excitability. This means that the muscle

Accepted Answer

A)   shortens its length.
B)   recoils to its original resting length.
C)   stretches beyond its normal length.
D)   responds to stimulation by the nervous system.
E)   excites itself.F) C) and D)
G) D) and E)

Question 9

After contraction has occurred, the calcium is

Accepted Answer

A)   destroyed by cholinesterase.
B)   chemically bound to the cross bridges.
C)   secreted by the Golgi apparatus to the outside of the cell.
D)   released from troponin.
E)   returned to the sarcolemma.F) A) and E)
G) D) and E)

Question 10

A drug that interferes with the active transport of calcium ions from the sarcoplasm back into the sarcoplasmic reticulum would result in

Accepted Answer

A)   relaxation of the muscle fiber.
B)   contraction with no relaxation.
C)   muscle hypertrophy.
D)   fibrosis of the muscle.
E)   an imbalance of blood calcium.F) A) and B)
G) A) and C)

Question 11

Which of the following situations occurs in electrically excitable cells?

Accepted Answer

A)   When Na+ ion channels open, K+ ion channels close.
B)   The sodium-potassium pump moves sodium into the cell.
C)   Depolarization causes voltage-gated sodium ion channels to open.
D)   Sodium ion channels are opened by high extracellular calcium levels.
E)   The opening and closing of ligand-gated channels cause depolarization.F) C) and E)
G) A) and E)

Question 12

Why does muscle activity affect the temperature of the body?

Accepted Answer

A)   The rate of chemical reactions increases in muscle fibers during contraction, so the rate of heat production also increases.
B)   Muscle contraction generates pyrogens which reset the body's internal thermostat to a higher temperature.
C)   Muscle activity directs more warm blood to the muscles away from the central core causing a cooling effect on your internal organs.
D)   Increased muscle activity causes a rise in adipose stores which increases the insulation value of the body.E) C) and D)
F) A) and C)

Question 13

Which of the following is true during the resting membrane potential?

Accepted Answer

A)   Sodium ion concentration is greater inside cells.
B)   Negatively charged proteins are more concentrated outside the cell.
C)   A greater concentration of calcium ions is found inside the cell.
D)   Potassium is concentrated primarily inside the cell.
E)   None of these choices reflect what occurs during the resting membrane potential.F) A) and E)
G) C) and D)

Question 14

Whole muscles can respond in a graded fashion to stimuli by varying

Accepted Answer

A)   the force of contraction of individual muscle fibers.
B)   the number of motor units recruited.
C)   the amplitude of the action potential.
D)   the frequency of stimulus.
E)   thresholds.F) B) and C)
G) B) and E)

Question 15

Which of the following is NOT a function of skeletal muscle?

Accepted Answer

A)   body movement
B)   maintenance of posture
C)   respiration
D)   constriction of organs
E)   production of heatF) A) and E)
G) All of the above

Question 16

A cancer patient is told by their physician that their colon is lacking smooth muscle tone. What does this mean?

Accepted Answer

A)   The colon is developing action potentials too rapidly.
B)   The colon has too many shallow invaginations of cell membranes.
C)   The colon is unable to maintain constant tension for sustained periods of time.
D)   The intracellular cytoskeleton is overactive.E) B) and C)
F) A) and D)

Question 17

-What does "D" represent on the diagram?

Accepted Answer

A)   threshold
B)   depolarization
C)   depolarization phase of action potential
D)   repolarization phase of action potentialE) B) and C)
F) A) and D)

Question 18

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

Question 19

Incomplete tetanus

Accepted Answer

A)   is the time during which the tissue cannot respond again.
B)   results in complete and incomplete tetanus.
C)   is the condition in which the muscle fiber only partially relaxes between contractions.
D)   is the condition in which stimuli occur so rapidly that there are no intervening relaxations.
E)   is the constant tension produced by muscles for long periods of time.F) C) and D)
G) B) and D)

Question 20

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 E)
G) A) and C)

Exam 9: Muscular System: Histology and Physiology

After contraction has occurred, the calcium is

Correct AnswerverifiedShow Answer

Which of the following statements concerning fast-twitch muscle fibers is true?

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

Which type of muscle tissue would cause flexion and extension of the arm?

Correct AnswerverifiedShow Answer

Muscles exhibit the property of excitability. This means that the muscle

Correct AnswerverifiedShow Answer

Smooth muscle and cardiac muscle are similar in that they both

Correct AnswerverifiedShow Answer

A drug that interferes with the active transport of calcium ions from the sarcoplasm back into the sarcoplasmic reticulum would result in

Correct AnswerverifiedShow Answer

Whole muscles can respond in a graded fashion to stimuli by varying

Correct AnswerverifiedShow Answer

Aerobic exercise

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Which of the following is true during the resting membrane potential?

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Why does muscle activity affect the temperature of the body?

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Incomplete tetanus

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Visceral smooth muscle

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Which of the following is NOT a function of skeletal muscle?

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Alex is participating in a 50 meter dash. Predict the most important chemical process his muscles will rely on during this race.

Correct AnswerverifiedShow Answer

Which of the following situations occurs in electrically excitable cells?

Correct AnswerverifiedShow Answer

A cancer patient is told by their physician that their colon is lacking smooth muscle tone. What does this mean?

Correct AnswerverifiedShow Answer

-What does "D" represent on the diagram?

Correct AnswerverifiedShow Answer

What is the role of pacemaker cells?

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A child ingested an organophosphate poison used to kill insects. Soon the child's muscles began spastic contractions. Predict what occurred at the synaptic cleft.

Correct AnswerverifiedShow Answer

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