Question 1

Acetylcholine binds to a membrane bound receptor and causes ligand-gated sodium channels to open and results in

Accepted Answer

A)   hyperpolarization.
B)   depolarization.
C)   hypoplarization.
D)   no change in membrane potential.
E)   There is not enough information to predict the outcome.F) B) and D)
G) A) and E)

Question 2

Which type of respiration rapidly produces ATP for short time periods?

Accepted Answer

A)   Anaerobic respiration
B)   Aerobic respiration
C)   Both anaerobic respiration and aerobic respiration are correct.D) None of the above
E) A) and C)

Question 3

Due to the pattern of innervation of skeletal muscle, one would expect that

Accepted Answer

A)   there are fewer motor neurons than skeletal muscle fibers.
B)   there are fewer muscle fibers than motor neurons.
C)   the number of muscle fibers and motor neurons is equal.D) All of the above
E) A) and C)

Question 4

-What does "B" represent on the diagram?

Accepted Answer

A)   Threshold
B)   Depolarization
C)   Depolarization phase of action potential
D)   Repolarization phase of action potentialE) None of the above
F) C) and D)

Question 5

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) All of the above
G) A) and D)

Question 6

What is the power stroke?

Accepted Answer

A)   A protein found along the groove of the F-actin double helix
B)   A T tubule and two adjacent terminal cisternae
C)   The combination of myosin heads with active sites on actin molecules
D)   The movement of myosin head while attached to actin myofilament
E)   After exercise, the O2 taken in that exceeds the O2 required for resting metabolismF) A) and B)
G) D) and E)

Question 7

Which type of muscle tissue has spindle-shaped cells?

Accepted Answer

A)   Skeletal muscle
B)   Smooth muscle
C)   Cardiac muscle
D)   Both skeletal and cardiac muscle are correct.
E)   Both cardiac and smooth muscle are correct.F) B) and E)
G) C) and E)

Question 8

Tetanus of a muscle is thought to be caused by

Accepted Answer

A)   high Ca2+ concentrations in the sarcoplasm.
B)   the rapid movement of Na+ back into the sarcoplasmic reticulum.
C)   an increase in stimulus strength.
D)   increased temperature in the active muscle.
E)   decreased amounts of Ca2+ in muscle tissue.F) A) and D)
G) All of the above

Question 9

What is the role of pacemaker cells?

Accepted Answer

A)   They rapidly develop action potentials.
B)   They are shallow invaginations of the plasma membrane.
C)   They maintain relatively constant tension for a period of time.
D)   They are part of the intracellular cytoskeleton.
E)   They are enzymes that remove phosphate from myosin.F) B) and E)
G) C) and D)

Question 10

A fascicle

Accepted Answer

A)   is a bundle of reticular fibers.
B)   is surrounded by perimysium.
C)   is only found in smooth muscle.
D)   possesses an external lamina.
E)   is a bundle of collagen fibers.F) A) and B)
G) A) and C)

Question 11

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

Question 12

The sarcolemma is the

Accepted Answer

A)   plasma membrane of a muscle fiber.
B)   cytoplasm of a muscle fiber.
C)   structural and functional unit of the skeletal muscle fiber.
D)   contractile thread that extends the length of the muscle fiber.
E)   protein strand composed of actin.F) A) and D)
G) C) and E)

Question 13

Multiunit smooth muscle is located in the

Accepted Answer

A)   gastrocnemius.
B)   wall of the GI tract.
C)   wall of blood vessels.
D)   wall of the heart.
E)   reproductive system.F) B) and C)
G) None of the above

Question 14

Calcium ion blocking agents would most likely affect

Accepted Answer

A)   action potential propogation along the transverse tubules.
B)   release of Ca2+ from the sarcoplasmic reticulum.
C)   movement of the tropomyosin molecule.
D)   release of the myosin head from the G actin molecule.E) None of the above
F) All of the above

Question 15

Too much acetylcholinesterase causes

Accepted Answer

A)   continuous stimulation of the muscle fiber.
B)   rapid degradation of acetylcholine.
C)   voltage-gated Ca2+ channels opening in the presynaptic terminal.
D)   an increase in Na+ uptake by the muscle fiber.
E)   exocytosis of synaptic vesicles.F) B) and C)
G) A) and E)

Question 16

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 D)
G) B) and D)

Question 17

Functionally, smooth muscle

Accepted Answer

A)   is well adapted to anaerobic metabolism.
B)   exhibits autorhythmic contractions.
C)   contracts in response to slow increases in length.
D)   is unable to maintain tone.
E)   rapidly develops an oxygen deficit.F) B) and E)
G) All of the above

Question 18

Movements of the body are usually smooth and occur at differing rates because

Accepted Answer

A)   they are a mixture of isotonic and isometric contractions.
B)   motor units contract out of phase at their own particular rates.
C)   most muscle contractions closely resemble individual muscle twitches.
D)   muscles of different sizes contract at different rates.
E)   of the all-or-none principle.F) A) and D)
G) A) and C)

Question 19

Which of the following would be caused by a contraction of smooth muscle?

Accepted Answer

A)   Goose bumps
B)   Blood leaving the left ventricle of the heart
C)   Elevating the eyebrows
D)   Blinking the eyelids
E)   Deep inspirationF) A) and B)
G) A) and C)

Question 20

Troponin

Accepted Answer

A)   has two subunits.
B)   is part of the myosin myofilament.
C)   is a long, flexible protein.
D)   has a calcium-binding site.
E)   binds to ATP.F) A) and C)
G) A) and E)

Exam 9: Muscular System: Histology and Physiology

One cause of spastic paralysis might be

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Multiunit smooth muscle is located in the

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

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Troponin

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Calcium ion blocking agents would most likely affect

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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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What is the role of pacemaker cells?

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A fascicle

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Due to the pattern of innervation of skeletal muscle, one would expect that

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Movements of the body are usually smooth and occur at differing rates because

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What is the power stroke?

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Which type of muscle tissue has spindle-shaped cells?

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The sarcolemma is the

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Tetanus of a muscle is thought to be caused by

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Too much acetylcholinesterase causes

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Acetylcholine binds to a membrane bound receptor and causes ligand-gated sodium channels to open and results in

Correct AnswerverifiedShow Answer

Functionally, smooth muscle

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Which of the following would be caused by a contraction of smooth muscle?

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Which type of respiration rapidly produces ATP for short time periods?

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-What does "B" represent on the diagram?

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