Deck 10: Muscle Tissue

Question 1

The plasma membrane of a skeletal muscle fiber is called the

A)sarcolemma.
B)sarcomere.
C)sarcosome.
D)sarcoplasmic reticulum.
E)sarcoplasm.

Answer 1

A

Question 2

Nerves and blood vessels that service a muscle fiber are located in the connective tissues of its

A)endomysium.
B)perimysium.
C)sarcolemma.
D)sarcomere.
E)myofibrils.

Answer 2

A

Question 3

Which of the following is a recognized function of skeletal muscle?

A)produce movement
B)maintain posture
C)maintain body temperature
D)guard body entrances and exits
E)All of the answers are correct.

Answer 3

E

Question 4

The bundle of collagen fibers at the end of a skeletal muscle that attaches the muscle to bone is called a(n)

A)fascicle.
B)tendon.
C)ligament.
D)epimysium.
E)myofibril.

Question 5

Which of the following best describes the term sarcoplasmic reticulum?

A)protein that accounts for elasticity of resting muscle
B)repeating unit of striated myofibrils
C)storage and release site for calcium ions
D)thin filaments are anchored here
E)largely made of myosin molecules

Question 6

Interactions between actin and myosin filaments of the sarcomere are responsible for

A)muscle fatigue.
B)the conduction of neural stimulation to the muscle fiber.
C)muscle contraction.
D)muscle relaxation.
E)the striped appearance of skeletal muscle.

Question 7

The advantage of having many nuclei in a skeletal muscle fiber is

A)the ability to contract.
B)the ability to produce more ATP with little oxygen.
C)the ability to store extra DNA for metabolism.
D)the ability to produce large amounts of the muscle proteins needed for growth and repair.
E)the ability to produce nutrients for muscle contraction.

Question 8

Which of the following best describes the term sarcomere?

A)protein that accounts for elasticity of resting muscle
B)repeating unit of striated myofibrils
C)storage site for calcium ions
D)thin filaments are anchored here
E)largely made of myosin molecules

Question 9

The delicate connective tissue that surrounds the skeletal muscle fibers and ties adjacent muscle fibers together is the

A)endomysium.
B)perimysium.
C)epimysium.
D)superficial fascia.
E)periosteum.

Question 10

The repeating unit of a skeletal muscle fiber is the

A)sarcolemma.
B)sarcomere.
C)sarcoplasmic reticulum.
D)myofibril.
E)myofilament.

Question 11

Put the following structures in order from superficial to deep: 1. muscle fiber
2) perimysium
3) myofibril
4) fascicle
5) endomysium
6) epimysium

A)1,5,4,3,2,6
B)6,2,5,4,1,3
C)6,2,4,5,1,3
D)1,3,5,6,4,2
E)2,3,1,4,6,5

Question 12

A fascicle is

A)a group of muscle fibers that are encased in the perimysium.
B)the belly of a muscle.
C)a group of muscle fibers that are all part of the same motor unit.
D)a group of muscle fibers and motor neurons.
E)a collection of myofibrils in a muscle fiber.

Question 13

Muscle fibers differ from "typical cells" in that muscle fibers

A)lack a plasma membrane.
B)have many nuclei.
C)are very small.
D)lack mitochondria.
E)have large gaps in the cell membrane.

Question 14

The dense layer of connective tissue that surrounds an entire skeletal muscle is the

A)tendon.
B)epimysium.
C)endomysium.
D)perimysium.
E)fascicle.

Question 15

Muscle tissue,one of the four basic tissue groups,consists chiefly of cells that are highly specialized for

A)conduction.
B)contraction.
C)peristalsis.
D)cushioning.
E)secretion.

Question 16

The region of the sarcomere containing the thick filaments is the

A)Z line.
B)M line.
C)H band.
D)A band.
E)I band.

Question 17

Skeletal muscle fibers are formed from embryonic cells called

A)sarcomeres.
B)myofibrils.
C)myoblasts.
D)fascicles.
E)myomeres.

Question 18

Which of the following best describes the term Z line?

A)protein that accounts for elasticity of resting muscle
B)repeating unit of striated myofibrils
C)storage site for calcium ions
D)thin filaments are anchored here
E)largely made of myosin molecules

Question 19

At each end of the muscle,the collagen fibers of the epimysium,and each perimysium and endomysium,come together to form a

A)tendon.
B)satellite cell.
C)ligament.
D)tenosynovium.
E)sheath.

Question 20

In a sarcomere,thick filaments are linked laterally by proteins of the

A)Z line.
B)M line.
C)H band.
D)A band.
E)I band.

Question 21

Each thin filament consists of

A)two actin protein strands coiled helically around each other.
B)chains of myosin molecules.
C)six molecules coiled into a helical structure.
D)a rod-shaped structure with "heads" projecting from each end.
E)a double strand of myosin molecules.

Question 22

The skeletal muscle complex known as the triad consists of

A)actin,myosin,and filaments.
B)a transverse tubule and two terminal cisternae.
C)filaments,myofibrils,and sarcomeres.
D)A bands,H bands,and I bands.
E)actin,myosin,and sarcomeres.

Question 23

Figure 10-1 Skeletal Muscle Fiber
Use Figure 10-1 to answer the following questions:
What physiological process occurs in the structure labeled "7"?

A)release of neurotransmitter
B)conduction of the action potential into the cell interior
C)activity of acetylcholinesterase
D)release of protein into the muscle fiber
E)the sliding filament theory

Question 24

Which statement about the microscopic anatomy of skeletal muscle fibers is true?

A)Tubular extensions of the sarcolemma penetrate the fiber transversely.
B)Cross striations result from the lateral alignment of thick and thin filaments.
C)Each fiber has many nuclei.
D)Muscle fibers are continuous from tendon to tendon.
E)All of the answers are correct.

Question 25

At rest,the tropomyosin molecule is held in place by

A)actin molecules.
B)myosin molecules.
C)troponin molecules.
D)ATP molecules.
E)calcium ions.

Question 26

Since each myofibril is attached at either end of the muscle fiber,when sarcomeres shorten,the muscle fiber

A)lengthens.
B)shortens.
C)strengthens.
D)weakens.
E)pulls from the middle.

Question 27

Figure 10-1 Skeletal Muscle Fiber
Use Figure 10-1 to answer the following questions:
Where would calcium ions be predominately found?

A)1
B)2
C)4
D)8
E)9

Question 28

The thin filaments of striated muscle are made primarily of which protein(s)?

A)actin
B)tropomyosin
C)troponin
D)nebulin
E)All of the answers are correct.

Question 29

The area in the center of the A band that contains no thin filaments is the

A)Z line.
B)M line.
C)H band.
D)I band.
E)zone of overlap.

Question 30

Figure 10-1 Skeletal Muscle Fiber
Use Figure 10-1 to answer the following questions:
Which structure actively pumps calcium ions out of the sarcoplasm to produce relaxation?

A)6
B)7
C)1
D)3
E)2

Question 31

The series of membranous channels that surround each myofibril is the

A)sarcoplasmic reticulum.
B)sarcoplasm.
C)sarcomere.
D)sarcolemma.
E)endomysium.

Question 32

Figure 10-1 Skeletal Muscle Fiber
Use Figure 10-1 to answer the following questions:
Identify the structure labeled "1."

A)mitochondria
B)glycogen
C)ATP
D)myofibril
E)synaptic vesicle

Question 33

The region of the sarcomere that always contains thin filaments is the

A)Z line.
B)M line.
C)H band.
D)A band.
E)I band.

Question 34

Figure 10-1 Skeletal Muscle Fiber
Use Figure 10-1 to answer the following questions:
Which of the following are found in the structure labeled "3"?

A)actin
B)myosin
C)titin
D)tropomyosin
E)All of the answers are correct.

Question 35

Figure 10-1 Skeletal Muscle Fiber
Use Figure 10-1 to answer the following questions:
What is released from the structure labeled "9"?

A)sarcoplasm
B)acetylcholine
C)protein
D)calcium ions
E)acetylcholinesterase

Question 36

Which of the following best describes the term titin?

A)protein that accounts for elasticity of resting muscle
B)repeating unit of striated myofibrils
C)storage site for calcium ions
D)thin filaments are anchored here
E)largely made of myosin molecules

Question 37

When a skeletal muscle fiber contracts,

A)the H bands and I bands get smaller.
B)the zones of overlap get larger.
C)the Z lines get closer together.
D)the width of the A band remains constant.
E)All of the answers are correct.

Question 38

Each skeletal muscle fiber contains ________ myofibrils.

A)50 to 100
B)100 to 150
C)150 to 200
D)200 to 500
E)hundreds to thousands

Question 39

Cross-bridges are portions of

A)actin molecules.
B)myosin molecules.
C)troponin molecules.
D)tropomyosin molecules.
E)calcium ions.

Question 40

At rest,active sites on the actin are blocked by

A)myosin molecules.
B)troponin molecules.
C)tropomyosin molecules.
D)calcium ions.
E)ATP molecules.

Question 41

Figure 10-1 Skeletal Muscle Fiber
Use Figure 10-1 to answer the following questions:
Where is ATP is consumed?

A)1
B)2
C)3
D)6
E)3 and 6

Question 42

Which of the following acts as an ATPase during the contraction cycle of muscle?

A)actin molecules
B)troponin molecules
C)tropomyosin molecules
D)the head portion of the myosin molecule
E)the tail portion of the myosin molecule

Question 43

Each skeletal muscle fiber is controlled by a motor neuron at a single

A)synaptic knob.
B)sarcomere.
C)neuromuscular junction.
D)synaptic cleft.
E)transverse tubule.

Question 44

Which of the following become connected by myosin cross-bridges during muscle contraction?

A)thin filaments and thick filaments
B)thick filaments and titin filaments
C)z disks and actin filaments
D)thick filaments and t-tubules
E)thin filaments and t-tubules

Question 45

When calcium ion binds to troponin,

A)tropomyosin moves into the groove between the helical actin strands.
B)active sites on the myosin are exposed.
C)actin heads will bind to myosin.
D)muscle relaxation occurs.
E)myosin shortens.

Question 46

Triggering of the muscle action potential occurs after

A)acetylcholine binds to chemically-gated channels in the end plate membrane.
B)acetylcholinesterase binds to receptors on the end plate.
C)calcium ion binds to channels on the end plate.
D)the nerve action potential jumps across the neuromuscular junction.
E)Any of the above can produce an action potential in the muscle cell.

Question 47

The narrow space between the synaptic terminal and the muscle fiber is the

A)synaptic knob.
B)motor end plate.
C)motor unit.
D)synaptic cleft.
E)M line.

Question 48

The action potential is conducted into a skeletal muscle fiber by

A)motor end plates.
B)neuromuscular junctions.
C)transverse tubules.
D)triads.
E)sarcoplasmic reticulum.

Question 49

Receptors for acetylcholine are located on the

A)synaptic knob.
B)motor end plate.
C)sarcomere.
D)synaptic cleft.
E)transverse tubule.

Question 50

After death,muscle fibers run out of ATP and calcium begins to leak from the sarcoplasmic reticulum into the sarcoplasm.This results in a condition known as

A)tetany.
B)treppe.
C)depolarization.
D)rigor mortis.
E)oxygen debt.

Question 51

Active sites on the actin become available for binding after

A)actin binds to troponin.
B)troponin binds to tropomyosin.
C)calcium binds to troponin.
D)calcium binds to tropomyosin.
E)myosin binds to troponin.

Question 52

Figure 10-1 Skeletal Muscle Fiber
Use Figure 10-1 to answer the following questions:
Where are the myosin molecules located?

A)4
B)5
C)6
D)7
E)8

Question 53

Physical evidence that supports the sliding filament theory of muscle contraction includes

A)constant distance between Z lines during contraction.
B)decreased width of the H band during contraction.
C)increased width of the I band during contraction.
D)decreased width of the A band during contraction.
E)the I band + H band distance is constant during contraction.

Question 54

In response to action potentials arriving along the transverse tubules,the sarcoplasmic reticulum releases

A)acetylcholine.
B)sodium ions.
C)potassium ions.
D)calcium ions.
E)hydrogen ions.

Question 55

The most important factor in decreasing the intracellular concentration of calcium ion after contraction is

A)active transport of calcium across the sarcolemma.
B)active transport of calcium into the sarcoplasmic reticulum.
C)active transport of calcium into the synaptic cleft.
D)diffusion of calcium out of the cell.
E)diffusion of calcium into the sarcoplasmic reticulum.

Question 56

In rigor mortis

A)the myosin heads are attached to actin.
B)ATP is depleted.
C)muscles are inextensible.
D)cross-bridge cycling is absent.
E)All of the answers are correct.

Question 57

The following is a list of the events that occur during a muscle contraction. 1.Myosin cross-bridges bind to the actin.
2)The free myosin head splits ATP.
3)Calcium ion is released from the sarcoplasmic reticulum.
4)The myosin head pivots toward the center of the sarcomere.
5)Calcium ion binds to troponin.
6)The myosin head binds an ATP molecule and detaches from the actin.
The correct sequence of these events is

A)1,3,5,4,6,2.
B)5,1,4,6,2,3.
C)3,5,1,2,4,6.
D)3,5,1,4,6,2.
E)1,4,6,2,3,5.

Question 58

Figure 10-1 Skeletal Muscle Fiber
Use Figure 10-1 to answer the following questions:
Which structure contains the motor end plate?

A)1
B)2
C)3
D)5
E)8

Question 59

In a sarcomere,cross-bridge attachment occurs specifically in the

A)zone of overlap.
B)A band.
C)I band.
D)M line.
E)H band.

Question 60

Figure 10-1 Skeletal Muscle Fiber
Use Figure 10-1 to answer the following questions:
Identify the structure where ATP is produced.

A)6
B)7
C)1
D)3
E)2

Question 61

A muscle producing tension that peaks and falls at intermediate stimulus rates is said to be in

A)incomplete tetanus.
B)complete tetanus.
C)treppe.
D)wave summation.
E)recruitment.

Question 62

The type of contraction in which the muscle fibers do not shorten is called

A)tetany.
B)treppe.
C)concentric.
D)isotonic.
E)isometric.

Question 63

When contraction occurs,

A)the H bands get smaller.
B)the Z lines move closer together.
C)the width of the A band remains constant.
D)the I bands get smaller.
E)All of the answers are correct.

Question 64

The increase in muscle tension that is produced by increasing the number of active motor units is called

A)incomplete tetanus.
B)complete tetanus.
C)treppe.
D)wave summation.
E)recruitment.

Question 65

When acetylcholine binds to receptors at the motor end plate,the end plate membrane becomes

A)more permeable to sodium ions.
B)less permeable to sodium ions.
C)more permeable to calcium ions.
D)less permeable to potassium ions.
E)repolarized.

Question 66

A single motor neuron together with all the muscle fibers it innervates is called

A)an end foot.
B)an end plate.
C)a motor unit.
D)a dermatome.
E)a myotome.

Question 67

When a muscle is stimulated repeatedly at a high rate,the amount of tension gradually increases to a steady maximum tension.This is called

A)incomplete tetanus.
B)complete tetanus.
C)a twitch.
D)wave summation.
E)recruitment.

Question 68

The rapid rise and fall in force produced by a muscle fiber after a single action potential is

A)a tetanus.
B)an unfused tetanus.
C)a twitch.
D)an end plate potential.
E)a muscle action potential.

Question 69

Synaptic vesicles contain neurotransmitters that are released by ________ when the action potential arrives.

A)endocytosis
B)apoptosis
C)exocytosis
D)hydrolysis
E)sodium

Question 70

Which statement about excitation-contraction coupling is incorrect?

A)Calcium ion is released from the transverse tubule.
B)Calcium ion is released from the sarcoplasmic reticulum.
C)Tropomyosin moves to expose myosin binding sites on actin.
D)Troponin binds calcium ion and signals tropomyosin to move.
E)Relaxation requires uptake of calcium ion by the sarcoplasmic reticulum.

Question 71

The cytoplasm of the neuromuscular terminal contains vesicles filled with molecules of the neurotransmitter

A)epinephrine.
B)norepinephrine.
C)acetylcholine.
D)antidiuretic hormone.
E)adrenaline.

Question 72

How would the loss of acetylcholinesterase from the motor end plate affect skeletal muscle?

A)It would make the muscles less excitable.
B)It would produce muscle weakness.
C)It would cause spastic paralysis (muscles are contracted and unable to relax).
D)It would cause flaccid paralysis (muscles are relaxed and unable to contract).
E)It would have little effect on skeletal muscles.

Question 73

If a second stimulus arrives before the relaxation phase has ended,a second,more powerful contraction occurs.This is called

A)incomplete tetanus.
B)complete tetanus.
C)treppe.
D)wave summation.
E)recruitment.

Question 74

The muscle weakness of myasthenia gravis results from

A)insufficient acetylcholine release from presynaptic vesicles.
B)loss of acetylcholine receptors in the end-plate membrane.
C)the motor neuron action potential being too small to shock the muscle fibers.
D)excessive acetylcholinesterase that destroys the neurotransmitter.
E)inability of the muscle fiber to produce ATP.

Question 75

In which of the following would the motor units have the fewest muscle fibers?

A)muscles of the neck
B)postural muscles of the back
C)muscles that control the eyes
D)thigh muscles
E)calf muscles

Question 76

Suppose that you try to pick up an object and discover that it is much heavier than you expected. Which process must occur in the muscle to increase tension so you can pick up the object?

A)wave summation
B)isotonic contraction
C)complete tetanus
D)recruitment
E)treppe

Question 77

The contraction of a muscle exerts a pull on a bone because

A)muscles are attached to bones by ligaments.
B)muscles are attached to bones by bursae.
C)muscles are attached to bones by tendons.
D)muscle fibers directly attach to the periosteum of bone.
E)muscles elongate upon contraction.

Question 78

A patient takes a medication that blocks ACh receptors of skeletal muscle fibers. What is this drug's effect on skeletal muscle contraction?

A)increases tone in the muscle
B)causes a strong contraction similar to a "charlie horse" cramp
C)increases the muscle's excitability
D)produces a strong,continuous state of contraction
E)reduces the muscle's ability for contraction

Question 79

A weight-lifter strains to lift a heavy weight and there is no movement of the person's arms holding on to the weight. This type of contraction is called a/an ________ contraction.

A)isometric
B)tetanus
C)isotonic
D)treppe
E)concentric

Question 80

In an isotonic contraction,

A)muscle tension exceeds the load and the muscle lifts the load.
B)tension rises and falls but the muscle length is constant.
C)the peak tension is less than the load.
D)many twitches always fuse into one.
E)postural muscles stabilize the vertebrae.