Deck 10: Muscle Tissue

Question 1

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 1

A

Question 2

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

Answer 2

D

Question 3

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

Answer 3

B

Question 4

Skeletal muscle fibers are formed from embryonic cells called

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

Question 5

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

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

Question 6

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

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

Question 7

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

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

Question 8

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 9

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.

Question 10

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

A) contract much more forcefully.
B) produce more ATP with little oxygen.
C) store extra DNA for metabolism.
D) produce large amounts of muscle proteins.
E) produce nutrients for muscle contraction.

Question 11

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 12

________ can be described as a broad tendinous sheet.

A) fasciae
B) retinaculum
C) aponeurosis
D) interstitium
E) tympanum

Question 13

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

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

Question 14

Afascicle is a

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

Question 15

The repeating unit of a skeletal muscle fiber is the

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

Question 16

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 17

In a sarcomere, the central portion of 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 18

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 19

The plasma membrane of a skeletal muscle fiber is called the

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

Question 20

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 21

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 22

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 23

The series of membranous channels that surround each myofibril is the

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

Question 24

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

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

Question 25

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 26

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 27

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 28

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 29

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 30

When a skeletal muscle fiber contracts, the

A) H bands and I bands get larger.
B) zones of overlap get larger.
C) Z lines move further apart.
D) width of the A band increases.
E) All of the answers are correct.

Question 31

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 32

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 33

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 34

Figure 10-1 Skeletal Muscle Fiber
Use Figure 10-1 to answer the following questions:
Which structure has pumps to remove calcium ions from the sarcoplasm to produce relaxation?

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

Question 35

The skeletal muscle complex known as the triad consists of

A) actin, myosin, and titin 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 36

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 37

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 38

All of the following proteins are part of the thin filaments except

A) actin.
B) tropomyosin.
C) troponin.
D) titin.
E) None of the answers is correct; there are no exceptions.

Question 39

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 and calcium ions into the muscle fiber
E) opening of sodium channels and subsequent influx of sodium

Question 40

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 41

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 42

Thin filaments are mostly made of the protein

A) actin.
B) titin.
C) myosin.
D) tropomyosin.
E) nebulin.

Question 43

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 44

The structural theory that explains how a muscle fiber contracts is called the ________ theory.

A) sliding filament
B) excitation-contraction coupling
C) neuromuscular
D) muscle contraction
E) action-myosin interaction

Question 45

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

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 46

In the myofibril the thin filament is organized around a rod-like core protein called

A) titin.
B) actin.
C) G actin.
D) nebulin.
E) myosin.

Question 47

In the myofibril the protein that possesses the active site for myosin heads to bind is called

A) titin.
B) actin.
C) G actin.
D) nebulin.
E) myosin.

Question 48

When calcium ion binds to troponin,

A) tropomyosin rolls away from the active site.
B) active sites on the myosin are exposed.
C) actin heads will bind to myosin.
D) muscle relaxation occurs.
E) myosin shortens.

Question 49

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 50

In the sarcomere the protein that forms two twisted strands around a central rod-like protein is called

A) titin.
B) actin.
C) G actin.
D) nebulin.
E) myosin.

Question 51

Thick filaments are made of the protein

A) actin.
B) titin.
C) myosin.
D) tropomyosin.
E) nebulin.

Question 52

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 53

The region of sarcomere where thin and thick filaments are located is called the

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

Question 54

The complex of a transverse tubule and two adjacent terminal cisternae is known as a

A) trimer.
B) triad.
C) triptych.
D) trisome.
E) trilogy.

Question 55

Stem cells located between the endomysium and sarcolemma that function in the repair of damaged muscle tissue are called

A) myocytes.
B) satellite cells.
C) endocytes.
D) sarcocytes.
E) creatinocytes.

Question 56

The protein that is found in the Z line of a sarcomere is called

A) actinin.
B) titin.
C) nebulin.
D) myosin.
E) actin.

Question 57

In the sarcomere which elastic protein attaches the thick filament to the Z line?

A) titin
B) actin
C) G actin
D) nebulin
E) myosin

Question 58

Figure 10-1 Skeletal Muscle Fiber
Use Figure 10-1 to answer the following questions:
Identify the structure(s) where ATP is consumed?

A) 3
B) 6
C) 3 and 6
D) 7
E) 3 and 7

Question 59

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 60

The protein that regulates muscle contraction by controlling the availability of active sites on actin is called

A) actin.
B) titin.
C) myosin.
D) tropomyosin.
E) nebulin.

Question 61

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 62

Cross bridge detachment is caused by ________ binding to the myosin head.

A) ATP
B) calcium
C) magnesium
D) acetylcholine
E) acetylcholinesterase

Question 63

Which of the following is not true of acetylcholine?

A) It binds to receptor membrane channels.
B) It diffuses across the synaptic cleft.
C) It is stored in the neuron in vesicles.
D) It enters the muscle fiber to release calcium form the sarcoplasmic reticulum.
E) It is digested by acetylcholinesterase.

Question 64

Active sites become exposed when calcium ions bind to

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

Question 65

Triggering of the muscle action potential occurs after

A) acetylcholine binds to chemically-gated channels in the motor end plate.
B) acetylcholinesterase is released from synaptic vesicles into the synaptic cleft.
C) calcium ion binds to channels on the motor end plate.
D) the action potential jumps across the neuromuscular junction.
E) Any of these can produce an action potential in the muscle cell.

Question 66

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 67

Communication between axons and muscle fibers occurs at specialized synapses called

A) nervous units.
B) synaptic terminals.
C) motor end plates.
D) motor units.
E) neuromuscular junctions.

Question 68

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 69

Which of the following statements about excitation-contraction coupling is incorrect?

A) Calcium ions travel through 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 70

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 muscles to stay contracted.
D) It would cause muscles to stay relaxed.
E) It would have little effect on skeletal muscles.

Question 71

In rigor mortis

A) the myosin heads are attached to actin.
B) ATP is depleted.
C) calcium ions keep binding to troponin.
D) sustained contractions occur.
E) All of the answers are correct.

Question 72

The role of acetylcholinesterase is to

A) bind to ligand gated sodium channels.
B) activate acetylcholine.
C) release acetylcholine into the synaptic cleft.
D) transport acetylcholine across the synaptic cleft.
E) break down acetylcholine into acetate and choline components.

Question 73

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

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

Question 74

The sequence of processes that links the action potential to contraction is called

A) neuromuscular junction.
B) action potential propagation.
C) excitation-contraction coupling.
D) cross bridge formation.
E) sliding filament theory.

Question 75

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 76

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 77

At what point during excitation contraction coupling does exocytosis play a role?

A) during calcium ion reuptake into the sarcoplasmic reticulum
B) when sodium channels open up on the motor end plate
C) during acetylcholine release from the synaptic terminal
D) when the action potential surges through the T-tubules
E) when ATP splits into ADP and P on the free myosin head

Question 78

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 79

When acetylcholine binds to receptors at the motor end plate, the sarcolemma 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) less permeable to potassium and sodium ions.

Question 80

The following is a list of the events that occur during a muscle contraction. What is the correct sequence of these events?
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.

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