Muscle Tissue, Chapter 10

Question 1

A blending of epimysium, perimysium, and endomysium that forms a broad sheet at the end of a muscle is known as __________.

a sarcomere
an aponeurosis
a ligament
a myofibril

Answer 1

an aponeurosis

This is a flat sheet of connective tissue.

Question 2

What are the three types of muscle tissue?

skeletal, cardiac, and smooth
epimysium, perimysium, and endomysium
voluntary, involuntary, and resting
elastic, collagen, and fibrous

Answer 2

skeletal, cardiac, and smooth

Question 3

Why are skeletal muscles often called voluntary muscles?

ATP activates skeletal muscles for contraction.
Skeletal muscles contract when stimulated by neurons from the motor cortex.
Skeletal muscles contain myoneural junctions.
Connective tissue harnesses generated forces voluntarily

Answer 3

Skeletal muscles contract when stimulated by neurons from the motor cortex.

Think of how the different muscle types are controlled.

Question 4

Repeating contractile units that make up a myofibril are called __________.

thick filaments
thin filaments
sarcomeres
A bands

Answer 4

sarcomeres

Question 5

Nerves and blood vessels are contained within the connective tissues of the __________.

epimysium only
endomysium only
epimysium and endomysium
epimysium, perimysium, and endomysium

Answer 5

epimysium, perimysium, and endomysium

Question 6

The thin filaments consist of __________.

a helical array of troponin molecules
a helical array of myosin molecules
a pair of F-actin molecules twisted together
a pair of protein strands wound together to form chains of myosin molecules

Answer 6

a pair of F-actin molecules twisted together

These proteins do not have moving heads.

Question 7

All of the muscle fibers controlled by a single motor neuron constitute a __________.

sarcomere
myoneural junction
motor unit
cross-bridge

Answer 7

motor unit

This is analogous to what is necessary for machines to operate.

Question 8

Why is control over leg muscles LESS precise than control over the muscles of the eye?

A single muscle fiber is controlled by a single motor neuron.
Many muscle fibers are controlled by a single motor neuron.
Many muscle fibers are controlled by many motor neurons.
Single muscle fibers are controlled by many motor neurons

Answer 8

Many muscle fibers are controlled by a single motor neuron.

Question 9

The thick filaments consist of __________.

a pair of protein strands wound together to form chains of myosin molecules
a helical array of actin molecules
about 300 myosin molecules twisted around one another
a pair of protein strands wound together to form chains of actin molecules

Answer 9

about 300 myosin molecules twisted around one another

Question 10

According to the sliding filament theory, what is the physical change that takes place during contraction?

The thick filaments are sliding toward the center of the sarcomere alongside the thin filaments.
The Z lines are sliding toward the H zone.
The thin filaments are sliding toward the center of the sarcomere alongside the thick filaments.
The thick and thin filaments are sliding toward the center of the sarcomere together.

Answer 10

The thin filaments are sliding toward the center of the sarcomere alongside the thick filaments.

One set of filaments is centrally anchored in the sarcomere.

Question 11

Troponin and tropomyosin are two proteins that can prevent the contractile process by __________.

covering the active site and blocking the actin–myosin interaction
combining with calcium to prevent active site binding
inactivating the myosin to prevent cross-bridging
causing the release of calcium from the sacs of the sarcoplasmic reticulum

Answer 11

covering the active site and blocking the actin–myosin interaction

Question 12

The amount of tension produced by an individual muscle fiber ultimately depends on the __________.

all-or-none principle
number of pivoting cross-bridges
number of calcium ions released
number of contracting sarcomeres

Answer 12

number of pivoting cross-bridges

Each actin–myosin interaction is additive.

Question 13

The transmission of an action potential along the T tubules stimulates the release of calcium from which structure in the sarcomere?

troponin
myofibril
tropomyosin
terminal cisterna

Answer 13

terminal cisterna

Think of a space in which these ions can be contained.

Question 14

What determines the amount of tension produced in the skeletal muscle as a whole?

tension produced by the stimulated muscle fibers
recruitment by the stimulated muscle fibers
total number of muscle fibers stimulated
All of the listed responses are correct

Answer 14

tension produced by the stimulated muscle fibers

recruitment by the stimulated muscle fibers

total number of muscle fibers stimulated

Question 15

Peak tension production occurs when all motor units in the muscle contract in a state of __________.

treppe
wave summation
twitch
complete tetanus

Answer 15

complete tetanus

Question 16

In an isotonic contraction, __________.

cross-bridges must produce enough tension to exceed the load to be moved
tension in the muscle decreases as the resistance increases
tension in the muscle varies as the muscle shortens
muscle length does not change as a result of resistance

Answer 16

cross-bridges must produce enough tension to exceed the load to be moved

This contraction moves bones.

Question 17

Which of the following is an example of an isometric contraction?

walking
flexing the biceps muscle while holding a 10-pound weight
holding a heavy stack of books above the ground
picking up a toddler who is sitting on the floor

Answer 17

holding a heavy stack of books above the ground

No skeletal structures are moved.

Question 18

A high blood concentration of the enzyme creatine phosphokinase (CPK) usually indicates __________.

serious muscle damage
the release of stored energy
that an excess of energy is being produced
that the mitochondria are malfunctioning

Answer 18

serious muscle damage

Remember that most enzymes are intracellular.

Question 19

Mitochondrial activities are relatively efficient, but their rate of ATP generation is limited by the __________.

availability of oxygen
availability of carbon dioxide and water
energy demands of other organelles
presence of enzymes

Answer 19

availability of oxygen

Question 20

Which of the following has been correlated with muscle fatigue?

an increase in pH within the muscle fibers, which affects storage of glycogen
a decline in pH within the muscle, which alters enzyme activities
an increase in muscle performance resulting from an increased pain threshold
an increase in metabolic reserves within the muscle fibers

Answer 20

a decline in pH within the muscle, which alters enzyme activities

How do proteins function in the presence of waste from cell respiration?

Question 21

During the recovery period, the body’s oxygen demand is __________.

decreased below normal resting levels
unchanged
elevated above normal resting levels
an irrelevant factor

Answer 21

elevated above normal resting levels

Question 22

Which type of muscle fiber is dominant in a muscle such as the gastrocnemius, a calf muscle that contracts during standing and walking?

white fiber
fast fiber
slow fiber
intermediate fiber

Answer 22

slow fiber

Question 23

Extensive blood vessels, mitochondria, and myoglobin are found in the greatest concentration in __________.

slow fibers
type II fibers
fast fibers
intermediate fibers

Answer 23

slow fibers

Which type of muscle fiber uses the most oxygen?

Question 24

The length of time a muscle can continue to contract while supported by mitochondrial activities is referred to as __________.

aerobic endurance
anaerobic endurance
recruitment
hypertrophy

Answer 24

aerobic endurance

What describes an activity that uses oxygen?

Question 25

Which of the following may cause muscle atrophy?

a lack of regular stimulation of muscle fibers
paralysis
wearing a cast on a broken limb
All of the listed responses are correct.

Answer 25

a lack of regular stimulation of muscle fibers

paralysis

wearing a cast on a broken limb

Question 26

What type or types of muscle tissue do NOT contain sarcomeres?

skeletal
cardiac
smooth
All of the listed responses are correct.

Answer 26

smooth

Where do you see no striations?

Question 27

Structurally, how do smooth muscle cells differ from skeletal muscle cells?

Smooth muscle cells contain many nuclei.
Smooth muscle cells possess striations.
Smooth muscle cells contain a network of T tubules.
Smooth muscle cells lack myofibrils and sarcomeres.

Answer 27

Smooth muscle cells lack myofibrils and sarcomeres.

Some structures you find only in skeletal muscle.

Question 28

Which of the following is necessary for smooth muscle contraction?

T tubules must transmit the action potential to the sarcoplasmic reticulum.
The zone of overlap must increase, but the length of the M line must remain constant.
Calcium ions must interact with calmodulin to trigger muscle contraction.
Sarcomeres must contract as a result of cross bridges forming between actin and myosin

Answer 28

Calcium ions must interact with calmodulin to trigger muscle contraction.

This involves a protein not found in skeletal muscle.

Question 29

Smooth muscle contractions in the respiratory passageways cause __________.

a decrease in diameter, making it harder for to air flow
no change in the relative air flow
immediate death
an increase in diameter, making it harder for air to flow

Answer 29

a decrease in diameter, making it harder for to air flow

Think of the relative ease of water flowing through a large or a small funnel. How do they differ?

Question 30

Layers of smooth muscle in the reproductive tract of the female are important in __________.

movement of sperm if present
delivery of a newborn during parturition
movement of oocytes
all of the listed functions

Answer 30

movement of sperm if present

delivery of a newborn during parturition

movement of oocytes

Question 31

The cardiovascular system uses which types of muscle?

smooth and skeletal
skeletal and cardiac
cardiac and smooth
cardiac, smooth, and skeletal

Answer 31

cardiac and smooth

What structures undergo contraction in this system?

Question 32

The area of the A band in the sarcomere consists of __________.

thick filaments only
Z line, H band, and M line
thin filaments only
M line, H band, and zone of overlap

Answer 32

M line, H band, and zone of overlap

This includes areas with both thick and thin filaments.

Question 33

The order of the sequential–cyclic reactions that occur at an active site during cross-bridging is __________.

attach, return, pivot, detach
attach, detach, pivot, return
attach, pivot, detach, return
attach, return, detach, pivot

Answer 33

attach, pivot, detach, return

Think of general crawling movements in insects.

Question 34

Excitation–contraction coupling forms the link between __________.

the release of Ca and the binding of troponin to Ca
electrical activity in the sarcolemma and the initiation of a contraction
the neuromuscular junction and the sarcoplasmic reticulum
depolarization and repolarization

Answer 34

electrical activity in the sarcolemma and the initiation of a contraction

Question 35

Cardiac muscle has the feature of automaticity, which is the ability to contract without neural stimulation. Which of the following statements accurately explains this unique feature?

Calmodulin interacting with calcium and myosin light chain kinase triggers interactions between actin and myosin.
Because cardiac muscle is not under voluntary control, it does not respond to neural stimulation.
Specialized pacemaker cells within the heart determine the rate of contraction of heart muscle.
The heart is full of fast muscle fibers and can contract quickly enough not to require neural stimulation.

Answer 35

Specialized pacemaker cells within the heart determine the rate of contraction of heart muscle.

Think of an internal control center in this organ.

Question 36

The phases of a single twitch, in sequential order, are __________.

latent period, relaxation phase, contraction phase
relaxation phase, latent phase, contraction phase
latent period, contraction phase, relaxation phase
contraction phase, latent phase, relaxation phase

Answer 36

latent period, contraction phase, relaxation phase

What usually precedes an activity? What follows this?

Question 37

After contraction, a muscle fiber returns to its original length through __________.

involvement of all the sarcomeres along the myofibrils
elastic forces and the movement of opposing muscles
the tension produced by the initial length of the muscle fiber
the active mechanism for fiber elongation

Answer 37

elastic forces and the movement of opposing muscles

Muscle itself can only actively shorten.

Question 38

A muscle producing almost peak tension during rapid cycles of contraction and relaxation is said to be in __________.

complete tetanus
treppe
recruitment
incomplete tetanus

Answer 38

incomplete tetanus

Question 39

The process of complete tetanus is reached by __________.

increasing the rate of stimulation until the relaxation phase is completely eliminated
activating additional motor units
applying a second stimulus before the relaxation phase has ended
decreasing the concentration of calcium ions in the cytoplasm

Answer 39

increasing the rate of stimulation until the relaxation phase is completely eliminated

Question 40

The bacterium Clostridium tetani causes prolonged muscle contractions by doing which of the following?

inhibiting the mechanism that suppresses motor neuron activity
competing for the ACh receptor sites on the motor end plate
releasing a toxin that causes flaccid paralysis
causing a decrease in the amount of available aCH

Answer 40

inhibiting the mechanism that suppresses motor neuron activity

Muscles need both tension and relaxation to do their work.

Question 41

Which of the following would NOT be an effective source of energy for muscle contraction?

glycogen
ATP
DNA
creatine

Answer 41

DNA

What are fuels available to muscle cells?

Question 42

What are the two mechanisms used to generate ATP from glucose?

cytoplasm and mitochondria
aerobic respiration and glycolysis
ADP and creatine phosphate
None of the listed responses is correct.

Answer 42

aerobic respiration and glycolysis

Question 43

In glycolysis, glucose is broken down to pyruvic acid, which is converted to __________.

glycogen
citric acid
lactic acid
acetyl-CoA

Answer 43

lactic acid

This compound will cause problems as it accumulates.

Question 44

Johnny, a 55-pound, 6-year-old boy, wants to be as strong as some of the professional weight lifters he sees on television. He goes outside, grabs the front bumper of his mother’s SUV, and attempts to raise it off the ground. The SUV does not move, but Johnny has succeeded in demonstrating which kind of muscle contraction?

eccentric
isotonic
isometric
concentric

Answer 44

isometric

Which contraction does not involve bones moving?

Question 45

On average, girls have smaller muscles and therefore less muscle mass than boys. Which hormones cause this difference between girls and boys?

epinephrine and testosterone
growth hormone and testosterone
epinephrine and thyroid hormone
thyroid hormone and growth hormone

Answer 45

growth hormone and testosterone

Question 46

Which hormone is responsible for stimulating muscle metabolism and increasing the force of contraction during a sudden crisis?

epinephrine
testosterone
growth hormone
thyroid hormone

Answer 46

epinephrine

Question 47

Which type of skeletal muscle fibers has low fatigue resistance?

fast fiber
intermediate fiber
slow fiber
type I fiber

Answer 47

fast fiber

Which fiber uses the least amount of oxygen?

Question 48

Which of the following is an example of an activity that requires anaerobic endurance?

a 50-yard dash
running a marathon
a 3-mile run
a 10-mile bicycle ride

Answer 48

a 50-yard dash

Question 49

Athletes training to develop anaerobic endurance perform __________.

a combination of weight training and marathon running
infrequent, long, relaxing workouts
stretching, flexibility, and relaxation exercises
frequent, brief, intensive workouts

Answer 49

frequent, brief, intensive workouts

What activities develop this type of endurance?

Question 50

What is the major support that the muscular system gets from the cardiovascular system?

nutrient and oxygen delivery and carbon dioxide removal
a direct response by controlling the heart rate and the respiratory rate
decreased volume of blood and rate of flow for maximal muscle contraction
constriction of blood vessels and decrease in heart rate for thermoregulatory control

Answer 50

nutrient and oxygen delivery and carbon dioxide removal

Think of what is transported in muscle.