Deck 9: Muscle Tissue

Question 1

Figure 9- 2 Muscle Contractions
Use Figure 9- 2 to answer the following questions:
During anaerobic glycolysis

A) pyruvic acid is produced.
B) oxygen is not consumed.
C) ATP is produced.
D) all of the above
E) B and C only

Answer 1

D

Question 2

Because skeletal muscle contractions demand large quantities of ATP, skeletal muscles have

A) a rich nerve supply.
B) a rich blood supply.
C) abundant mitochondria.
D) A, B, and C
E) both B and C

Answer 2

E

Question 3

When calcium ion binds to troponin,

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

Answer 3

B

Question 4

Which of the following best describes the term muscle origin?

A) connective tissue that surrounds an entire muscle
B) tendon attachment that doesn't move
C) connective tissue that surrounds a single muscle fiber
D) broad tendon sheet
E) tendon attachment that moves

Question 5

Figure 9- 2 Muscle Contractions
Use Figure 9- 2 to answer the following questions:
What is thought to happen in a muscle during the response shown in graph a)?

A) It is aged and has lost contractile proteins.
B) There is a gradual increase in the concentration of calcium ions in the sarcoplasm.
C) It is producing more ATP as tension increases.
D) It is fatigued and must make repeated efforts to twitch normally.
E) It is getting stronger with exercise.

Question 6

The region of the sarcomere containing the thick filaments is the

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

Question 7

During the recovery period the body's need for oxygen is increased because

A) the muscles are not producing ATP.
B) muscle cells are producing energy anaerobically.
C) the liver requires more oxygen to produce lactic acid.
D) the individual is panting.
E) additional oxygen is required to restore energy reserves consumed during exercise.

Question 8

Nerves and blood vessels that service the muscle fibers are located in the connective tissues of the

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

Question 9

At rest, active sites on the actin are blocked by

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

Question 10

Figure 9- 1 Skeletal Muscle Fiber
Use Figure 9- 1 to answer the following questions:
Creatine phosphate

A) cannot transfer its phosphate group to ADP.
B) is produced by the process of anaerobic respiration.
C) is only formed during strenuous exercise.
D) can replace ATP in binding to myosin molecules during contraction.
E) acts as an energy reserve in muscle tissue.

Question 11

Figure 9- 2 Muscle Contractions
Use Figure 9- 2 to answer the following questions:
What is the contraction in graph a) called?

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

Question 12

The plasma membrane of skeletal muscle is called the

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

Question 13

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

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

Question 14

Figure 9- 1 Skeletal Muscle Fiber
Use Figure 9- 1 to answer the following questions:
What physiological process occurs in the structure labeled "7"?

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

Question 15

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

Question 16

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

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

Question 17

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

A) muscles are attached to bones by bursae.
B) muscles are attached to bones by tendons.
C) muscles are attached to bones by ligaments.
D) A or C
E) A, B, or C

Question 18

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

A) produce movement
B) guard body entrances and exits
C) maintain body temperature
D) maintain posture
E) all of the above

Question 19

Synaptic vesicles containing neurotransmitters are released by when the action potential arrives.

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

Question 20

Which of the following hormones directly stimulates growth of muscle tissue, leading to increased muscle mass?

A) testosterone
B) epinephrine
C) calcitonin
D) parathyroid hormone
E) thyroid hormone

Question 21

Which of the following statements is are) true regarding human muscles?

A) Eye muscles are composed entirely of fast fibers.
B) Slow fibers are abundant in the calf muscles.
C) Most have both slow and fast fibers.
D) Slow fibers are abundant in the back muscles.
E) All of the above.

Question 22

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

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

Question 23

Calcium ions are binding to troponin during the of a muscle twitch.

A) latent period
B) contraction phase
C) relaxation phase
D) recovery phase
E) both A and B

Question 24

Which of these would lead to increased oxygen consumption?

A) increased muscle activity
B) increased conversion of lactic acid to glucose
C) increased heat production
D) increased aerobic respiration by muscle cells
E) all of the above

Question 25

Compared to a "typical" body cell, skeletal muscle cells are

A) capable of rapid shortening against a load.
B) filled with crystalline 3- D arrays of fibrous proteins.
C) multinucleate.
D) larger than normal cells.
E) all of the above

Question 26

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

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

Question 27

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

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

Question 28

C:\User Figure 9- 2 Muscle Contractions
Use Figure 9- 2 to answer the following questions:
To produce a contraction similar to the one in graph b), the muscle

A) must be stimulated to the point of fatigue.
B) gradually warms up.
C) must be stimulated again before it has relaxed from the previous stimulation.
D) is excited by a stimulus of increasing intensity.
E) is caused to produce isolated twitches.

Question 29

Figure 9- 1 Skeletal Muscle Fiber
Use Figure 9- 1 to answer the following questions:
Which of the following is not characteristic of smooth muscle?

A) Smooth muscles are uninucleate.
B) The thin filaments of smooth muscle fibers are attached to dense bodies.
C) Smooth muscle connective tissue forms tendons and aponeuroses.
D) Smooth muscles do not contain sarcomeres.
E) Neurons that innervate smooth muscles are under involuntary control.

Question 30

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) largely made of myosin molecules
D) thin filaments are anchored here
E) storage site for calcium ions

Question 31

The type of muscle fiber that is most resistant to fatigue is the fiber.

A) slow
B) intermediate
C) anaerobic
D) high- density
E) fast

Question 32

Which of the following statements is incorrect?

A) Skeletal muscles are responsible for the pumping action of the heart.
B) The contractions of skeletal muscles pull on tendons and move bones of the skeleton.
C) Skeletal muscles store nutrient reserves.
D) Skeletal muscle contractions help maintain body temperature.
E) Skeletal muscles support the weight of some internal organs.

Question 33

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

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

Question 34

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

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

Question 35

Which of the following statements is false?

A) Skeletal muscle contractions may be summated.
B) Cardiac muscle contractions cannot be summated.
C) Cardiac muscle stimulation is neural.
D) Skeletal muscle stimulation is neural.
E) Cardiocytes are interconnected through intercalated discs.

Question 36

Which of the following is not a type of motor unit?

A) red-slow twitch
B) red-fast twitch
C) white-slow twitch
D) white-fast twitch
E) All of these are well known.

Question 37

Figure 9- 1 Skeletal Muscle Fiber
Use Figure 9- 1 to answer the following questions:
Which structure actively pumps calcium ions out of the sarcoplasm to produce relaxation?

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

Question 38

Figure 9- 1 Skeletal Muscle Fiber
Use Figure 9- 1 to answer the following questions:
Where are the myosin molecules located?

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

Question 39

When contraction occurs,

A) the width of the A band remains constant.
B) the I bands get smaller.
C) the H bands get smaller.
D) the Z lines move closer together.
E) all of the above

Question 40

Triggering of the muscle action potential occurs after

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

Question 41

Large- diameter, densely packed myofibrils, large glycogen reserves, and few mitochondria are characteristics of

A) fast fibers.
B) red muscles.
C) slow fibers.
D) fatty muscles.
E) intermediate fibers.

Question 42

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

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

Question 43

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

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

Question 44

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

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

Question 45

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

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

Question 46

Figure 9- 1 Skeletal Muscle Fiber
Use Figure 9- 1 to answer the following questions:
Cross- bridges are portions of

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

Question 47

How would a drug that blocks acetylcholine receptors at the motor end plate affect skeletal muscle?

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

Question 48

Figure 9- 1 Skeletal Muscle Fiber
Use Figure 9- 1 to answer the following questions:
Physical evidence that supports the sliding filament theory of muscle contraction includes

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

Question 49

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

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

Question 50

Figure 9- 1 Skeletal Muscle Fiber
Use Figure 9- 1 to answer the following questions:
In which of the following would the motor units have the fewest muscle fibers?

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

Question 51

Fast fibers

A) have low resistance to fatigue.
B) have many mitochondria.
C) rely on aerobic metabolism.
D) have twitches with a very brief contraction phase.
E) both A and D

Question 52

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

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

Question 53

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

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

Question 54

The repeating unit of a skeletal muscle fiber is the

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

Question 55

Skeletal muscle fibers are formed from embryonic cells called

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

Question 56

Figure 9- 2 Muscle Contractions
Use Figure 9- 2 to answer the following questions:
What is the contraction in graph d) called?

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

Question 57

Figure 9- 1 Skeletal Muscle Fiber
Use Figure 9- 1 to answer the following questions:
Identify the structure labeled "1."

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

Question 58

During the recovery period following exercise, all of the following are true, except

A) the muscle actively produces ATP.
B) heat is generated.
C) oxygen is consumed at above the resting rate.
D) lactic acid is removed from muscle cells.
E) muscle fibers are unable to contract.

Question 59

Which of the following is not a function of smooth muscle tissue?

A) forcing blood from the heart into the major arteries
B) altering the diameter of the respiratory passageways
C) moving food materials along the digestive tract
D) elevating hairs on the arm
E) forcing urine out of the urinary tract

Question 60

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

A) are very small.
B) lack mitochondria.
C) lack a plasma membrane.
D) have many nuclei.
E) both B and C

Question 61

Fast muscle fibers can adapt to aerobic metabolism by generating more mitochondria in response to

A) sustained low levels of muscle activity.
B) high amounts of oxygen.
C) repeated, exhaustive stimulation.
D) increased levels of testosterone.
E) prolonged periods of inactivity.

Question 62

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

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

Question 63

Which of the following best describes the term sarcoplasmic reticulum?

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

Question 64

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

A) epinephrine.
B) antidiuretic hormone.
C) norepinephrine.
D) acetylcholine.
E) all of the above

Question 65

Which of the following muscles would contract more forcefully?

A) a muscle receiving 20 to 25 action potentials per second
B) a muscle receiving 10 to 15 action potentials per second

Question 66

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

A) shortens.
B) weakens.
C) lengthens.
D) strengthens.
E) not enough information to say

Question 67

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

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

Question 68

Aerobic metabolism normally provides percent of the ATP demands of a resting muscle cell.

A) 100
B) 95
C) 50
D) 70
E) 25

Question 69

Figure 9- 1 Skeletal Muscle Fiber
Use Figure 9- 1 to answer the following questions:
Identify the structure where ATP is produced.

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

Question 70

Figure 9- 1 Skeletal Muscle Fiber
Use Figure 9- 1 to answer the following questions:
In an isotonic contraction,

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

Question 71

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

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

Question 72

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

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

Question 73

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

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

Question 74

The action potential is conducted into a skeletal muscle fiber by

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

Question 75

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

A) peristalsis.
B) contraction.
C) conduction.
D) cushioning.
E) any of the above

Question 76

Figure 9- 1 Skeletal Muscle Fiber
Use Figure 9- 1 to answer the following questions:
During activities requiring aerobic endurance

A) oxygen debts are common.
B) glycogen and glycolysis are the primary sources of reserve energy.
C) fatigue occurs in a few minutes.
D) most of the muscle's energy is produced in mitochondria.
E) oxygen is not required.

Question 77

Which of the following best describes the term Z line?

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

Question 78

Figure 9- 1 Skeletal Muscle Fiber
Use Figure 9- 1 to answer the following questions:
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 79

Figure 9- 1 Skeletal Muscle Fiber
Use Figure 9- 1 to answer the following questions:
Which structure contains the motor end plate?

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

Question 80

Muscular force can be adjusted to match different loads by

A) recruiting larger motor units.
B) varying the frequency of action potentials in motor neurons.
C) recruiting more motor units.
D) A, B, and C
E) None of the above-muscle contraction is all- or- none.