Deck 8: Movement

Question 1

A muscle relaxes after contracting when

A) calcium is taken up by internal organelles.
B) internal acetylcholine is broken apart by acetylcholinesterase.
C) troponin is taken up by internal organelles.
D) myosin and actin begin to interact.

Answer 1

calcium is taken up by internal organelles.

Question 2

Nutrients are moved through the digestive tract by _________ muscle.

A) smooth
B) cardiac
C) striated
D) both smooth and striated

Answer 2

smooth

Question 3

The muscles of the arms and shoulders contain

A) approximately equal amounts of fast and slow-twitch fibers,making them well-suited for both endurance and explosive movements.
B) higher proportions of slow-twitch fibers,making them better suited for endurance than for explosive movements.
C) higher proportions of fast-twitch fibers,making them better suited for explosive movements than for endurance movements.
D) higher proportions of fast-twitch fibers,making them better suited for endurance than for explosive movements.

Answer 3

higher proportions of fast-twitch fibers,making them better suited for explosive movements than for endurance movements.

Question 4

The detachment of actin and myosin molecules requires

A) calcium.
B) sodium.
C) acetylcholine.
D) energy.

Question 5

What causes muscles to twitch?

A) depolarization of the muscle fiber produced by an influx of sodium ions
B) depolarization of the muscle fiber produced by an influx of potassium ions
C) hyperpolarization of the muscle fiber produced by an influx of calcium ions
D) hyperpolarization of the muscle fiber produced by an outflow of potassium ions

Question 6

What is the function of striated muscles?

A) control blood pressure and move the eyes and lung
B) move nutrients through the digestive tract and move bones
C) move the heart and the bones
D) control blood pressure and move the heart

Question 7

One major difference between striated and smooth muscles is that

A) smooth muscles move the voluntary system and striated muscles move automatic systems.
B) striated muscles are responsible for fast twitch and smooth muscles are responsible for slow twitch.
C) striated muscles move mostly voluntary systems while smooth muscles move involuntary,automatic systems.
D) smooth muscles are made up of myofibrils and striated muscle is made up of only sarcomeres.

Question 8

Fast-twitch fibers contract up to _________ times more rapidly than slow-twitch fibers.

A) 3
B) 8
C) 10
D) 12

Question 9

The arrival of an action potential causes

A) calcium to enter the muscle fiber.
B) calcium to be released by internal organelles.
C) acetylcholine to enter the muscle fiber.
D) acetylcholine to be released by internal organelles.

Question 10

Single segments of a myofibril are known as

A) sarcomeres.
B) twitches.
C) Z lines.
D) troponins.

Question 11

The long strands of protein running the length of a muscle fiber are known as

A) sarcomeres.
B) myofibrils.
C) Z lines.
D) troponins.

Question 12

In a resting muscle fiber,_________ is covered by _________.

A) actin;troponin
B) actin;calcium
C) myosin;troponin
D) myosin;calcium

Question 13

The lungs are moved by _________ muscle.

A) smooth
B) cardiac
C) striated
D) both smooth and striated

Question 14

Rigor mortis,or the muscle stiffness present after death,results primarily from

A) a drop in acetylcholine levels.
B) a lack of energy needed to separate actin and myosin molecules.
C) an increase in intracellular calcium concentrations.
D) the breakdown of troponin molecules.

Question 15

A Z line is a

A) segment of myofibril.
B) type of muscle fiber.
C) boundary between adjacent sarcomeres.
D) boundary between adjacent myofibrils.

Question 16

Slow-twitch fibers are a type of

A) myosin filament.
B) actin filament.
C) myofibril.
D) sarcomere.

Question 17

Action potentials

A) do not occur in muscle fibers.
B) spread out in two directions on either side of a receptor site.
C) travel in only one direction,from one end of a muscle fiber to the other.
D) result from the opening of potassium channels.

Question 18

Actin filaments are _________ myosin filaments.

A) thin fibers surrounded by
B) thick fibers surrounded by
C) thin fibers surrounding
D) thick fibers surrounding

Question 19

Muscle fibers contract when Z lines move _________ and the sarcomeres _________.

A) apart;stretch
B) apart;shorten
C) together;stretch
D) together;shorten

Question 20

Muscle fibers respond to

A) serotonin.
B) glutamate.
C) dopamine.
D) acetylcholine.

Question 21

Compared to the muscles of young adults,the muscles of elderly people

A) contain fibers that are more angular than round.
B) show a more even distribution of slow and fast twitch fibers.
C) are more likely to be hybrids of fast and slow twitch fibers.
D) are more likely to be made up of slow twitch fibers.

Question 22

The lower gravity experienced by astronauts

A) does not affect muscle mass.
B) increases muscle mass.
C) decreases muscle mass.
D) converts fast-twitch muscles to slow-twitch muscles.

Question 23

Endurance exercise can convert Type _________ fibers into Type _________ fibers.

A) IIb;IIa
B) IIa;IIb
C) I;II.
D) II;I

Question 24

An athlete with likely potential in Olympic weightlifting would probably have _________ in the quadriceps muscle.

A) about the same number of fast- and slow-twitch fibers
B) more fast- than slow-twitch fibers
C) more slow- than fast-twitch fibers
D) only fast-twitch muscles

Question 25

Age-related changes in muscle function

A) are related to genetics and cannot be changed.
B) can be completely reversed through exercise.
C) cannot be reversed,but people can compensate somewhat for these changes by exercising.
D) cannot be reversed,but people can compensate somewhat for these changes by eating carefully.

Question 26

Age-related loss in muscle mass appears to begin around the age of _________ years.

A) 25
B) 50
C) 75
D) 90

Question 27

If you go for a long run,you are using mostly _________ muscles that use _________ metabolism.

A) fast twitch;anaerobic
B) fast twitch;aerobic
C) Type I;aerobic
D) Type I;anaerobic

Question 28

Which of the following processes usually results in muscle fatigue?

A) Using muscles increases the breakdown of acetylcholinesterase.
B) Muscle fiber sodium channels become "leaky" during prolonged use.
C) Internal organelles responsible for picking up calcium develop "leaky channels" as muscles are used.
D) Actin and myosin molecules break due to overuse.

Question 29

The proportion of fast and slow-twitch fibers found in an individual's quadriceps muscle is primarily determined by the

A) individual's diet.
B) number of hours the individual spends each week engaged in anaerobic activity,like weightlifting.
C) individual's genetics.
D) number of hours the individual spends each week engaged in aerobic activity,like running or cycling.

Question 30

Muscles dominated by slow-twitch fibers appear _________ due to the presence of _________.

A) white;calcium
B) white;myoglobin
C) red;calcium
D) red;myoglobin

Question 31

Observations of the muscle fibers of people who have experienced spinal cord damage suggest that neural input is especially important to the maintenance of

A) fast-twitch fibers.
B) slow-twitch fibers.
C) both fast and slow-twitch fibers.
D) neither fast nor slow-twitch fibers.

Question 32

What happens to the rate of firing in motor neurons as we age?

A) No changes occur.
B) Firing rates decrease,leading to slower and weaker muscle contractions.
C) Firing rates increase,leading to uncomfortable cramping.
D) Firing rates decrease,but muscle fibers are able to compensate for these changes.

Question 33

Brandon loves to spend many hours per week in the weightroom,and he is quite muscular.Brandon's muscles have enlarged as a result of

A) scar tissue.
B) the production of more muscle fibers.
C) the production of more troponin.
D) the production of more actin and myosin filaments.

Question 34

Jennifer has signed up for a jogging class this term.By the end of the term,it is likely that:

A) none of Jennifer's muscle fibers will change type.
B) some of her Type IIa fibers will be converted into Type IIb fibers.
C) some of her Type IIb fibers will be converted into Type IIa fibers.
D) some of her Type II fibers will be converted into Type I fibers.

Question 35

The development of muscle tissue is related to

A) estrogens (female hormones)
B) androgens (male hormones)
C) both estrogens and androgens
D) neither estrogens nor androgens

Question 36

Endurance activities,such as distance running,rely primarily on _________ muscles using _________ metabolism.

A) fast-twitch;aerobic
B) fast-twitch;anaerobic
C) slow-twitch;aerobic
D) slow-twitch;anaerobic

Question 37

When an Olympic weightlifter uses explosive strength to lift a personal best,the _________ fibers in her legs are probably the most active,but the marathon runner relies on her _________ fibers.

A) slow twitch;fast twitch
B) fast twitch;slow twitch
C) Type I;Type IIa
D) Type I;Type IIb

Question 38

People with spinal cord injuries show a loss of _________ fibers.

A) Type I
B) Type IIb
C) Type IIa
D) both Type IIb and IIa

Question 39

The structure indicated by the number 3 in this image is a

A) myofibril.
B) z-line.
C) sarcomere.
D) motor end plate.

Question 40

Which of the following is the most accurate summary of the average strength differences between males and females?

A) Males and females have the potential to be equally strong,but males are usually stronger due to participating in more exercise.
B) On average,males are naturally stronger than females,but the gaps between male and female performance is decreasing due to more women participating in sports.
C) On average,females are naturally stronger than males,but males become stronger because they participate in more exercise.
D) Males and females have the potential to be equally strong,and the gaps between them are decreasing as more women participate in sports.

Question 41

Which of the following statements about muscle movement is true?

A) The only way muscles can cause movement is by contracting.
B) A single muscle can bend a joint by contracting and straighten it by relaxing.
C) Smooth muscles cause movement by contracting,while striated muscles cause movement by contracting and relaxing.
D) Striated muscles cause movement by contracting,but smooth muscles causes movement by contracting and relaxing.

Question 42

Which of the following areas of the spinal cord show enlargement of the ventral horns due to large numbers of motor neurons?

A) C1-C2;T2-T12
B) C1-C2;L1-S3
C) C3-T1;T2-T12
D) C3-T1;L1-S3

Question 43

An antagonistic pair of muscles is made up of

A) two extensor muscles at the same joint.
B) two flexor muscles at the same joint.
C) an extensor muscle and a flexor muscle at the same joint.
D) two complex muscles that allow joints like hips and elbows to move in many directions.

Question 44

Isaac observed a sample of motor units in which single neurons innervated fibers of the same type.This led Isaac to conclude that

A) neural input probably determines the identity of muscle fibers as slow or fast-twitch.
B) the organism that supplied the samples had probably suffered a spinal cord injury.
C) the organism that supplied the samples was very old.
D) his sample was not representative,and he needed to obtain more samples before reaching a conclusion.

Question 45

Athletic injuries to male and female athletes

A) occur at nearly the same rate.
B) are different largely due to hormonal influences.
C) are different largely due to structural differences.
D) are different because of the amount of time each gender usually spends in training.

Question 46

Motor neurons are

A) evenly distributed throughout the gray matter of the spinal cord.
B) evenly distributed throughout the white matter of the spinal cord.
C) more numerous in spinal segments serving the middle torso.
D) more numerous in spinal segments serving the arms and legs.

Question 47

As you bend your arm up to take a drink,the ________ muscles are active,and when you extend your arm to put the glass down,the ________ muscles are active.

A) striated;smooth
B) flexor;extensor
C) extensor;flexor
D) Type II;Type I

Question 48

A single motor unit usually contains a motor neuron and

A) one muscle fiber.
B) both fast and slow-twitch fibers.
C) either fast-twitch or slow-twitch fibers,but not a mixture of the two types.
D) a muscle spindle.

Question 49

Spinal motor neurons responsible for contracting muscles are known as _________ motor neurons.

A) alpha
B) beta
C) gamma
D) theta

Question 50

Muscles that straighten joints are known as

A) extensors.
B) flexors.
C) antagonists.
D) relaxers.

Question 51

One difference between the uterus and most other muscles is that

A) it does not lose strength when it is not used.
B) it does not contain any myosin.
C) its fibers do not respond to acetylcholine.
D) it requires less energy for each contraction.

Question 52

Motor neurons with small cell bodies usually innervate _________ muscle fibers.

A) Type I
B) Type IIa
C) Type IIb
D) combinations of Type IIa and Type IIb

Question 53

A single alpha motor neuron and the muscle fibers it enervates are known as a(n)

A) motor junction.
B) motor unit.
C) intrafusal unit.
D) antagonistic unit.

Question 54

Bending a joint requires

A) relaxation of extensors and flexors.
B) contraction of extensors and flexors.
C) relaxation of extensors and contraction of flexors.
D) contraction of extensors and relaxation of flexors.

Question 55

Alpha motor neurons are

A) small and unmyelinated.
B) small and myelinated.
C) large and unmyelinated.
D) large and myelinated.

Question 56

Which of the following sequences describes the typical order in which motor units are recruited?

A) Type IIb,Type IIa,Type I
B) Type II b,Type I,Type IIa
C) Type I,Type IIa,Type IIb
D) Type I,Type IIb,Type IIa

Question 57

Temporal summation may occur at the neuromuscular junction because

A) action potentials last longer than muscle contractions.
B) muscle contractions last longer than action potentials.
C) many motor neurons form synapses at a single neuromuscular junction.
D) acetylcholine is broken down slowly in the synaptic gap.

Question 58

Rates of knee injuries are

A) approximately the same for male and female athletes.
B) higher for female athletes than for male athletes.
C) higher for male athletes than for female athletes.
D) positively correlated with athletes' testosterone levels.

Question 59

Alpha motor neurons form connections with muscle fibers at the

A) muscle spindle.
B) antagonistic joint.
C) motor unit.
D) neuromuscular junction.

Question 60

Motor units that include Type IIb fibers

A) usually include Type IIa fibers as well.
B) produce about 100 times the force as units that include Type I fibers.
C) produce about one-third of the force produced by units that include Type IIa fibers.
D) are rarely found in humans.

Question 61

Intrafusal muscle fibers

A) are found in muscle spindles.
B) are responsible for muscle contraction.
C) provide feedback regarding muscle contraction.
D) are located at the junction between a muscle and tendon.

Question 62

The structure indicated by the number 2 in this image is known as a(n)

A) extrafusal fiber.
B) Ia sensory fiber.
C) gamma motor fiber.
D) intrafusal fiber.

Question 63

Compared with other sensory neurons,such as those that serve mechanoreceptors,Ia sensory fibers are

A) far less commonly found in the human nervous system.
B) less likely to be myelinated in the human nervous system.
C) very large and very fast.
D) very small and slow.

Question 64

Ia sensory fibers are activated in response to

A) contraction of muscle fibers.
B) stretching of Golgi tendon organs.
C) stretching of muscle spindles.
D) input from Ib fibers.

Question 65

Samantha is about to hand Megan a notebook that contains her biological psychology notes.Which of the following correctly describes how Megan's muscles will react to the heavy notebook?

A) The weight of the notebook will cause Megan's arm muscles to contract.This information will be sensed by mechanoreceptors around her joints and sent to her spinal cord via Ib fibers.The Ib fibers will excite gamma motor neurons,which will cause her arm to contract further to adjust to the heavier weight of the book.
B) The weight of the notebook will cause Megan's arm muscles to stretch.This information will be sensed by her spindles,and sent to her spinal cord by gamma motor neurons.The gamma motor neurons will inhibit the alpha motor neurons,causing her arm muscles to relax enough that she won't drop the book.
C) The weight of the notebook will cause Megan's arm muscles to contract.This information will be sensed by her Golgi tendon organs,and sent to her spinal cord by Ib sensory fibers.The Ib sensory fibers will excite alpha motor neurons that will cause her arm muscles to stretch enough that she won't drop the book.
D) The weight of the notebook will cause Megan's arm muscles to stretch.This information will be sensed by her spindles,and sent to her spinal cord by Ia sensory fibers.The Ia sensory fibers will excite alpha motor neurons that will cause her arm muscles to contract enough that she won't drop the book.

Question 66

In which of the following locations would we expect to find the greatest density of muscle spindles?

A) the legs
B) the torso
C) the hands
D) the arms

Question 67

Extrafusal muscle fibers

A) are found in muscle spindles.
B) are responsible for muscle contraction.
C) provide feedback regarding muscle contraction.
D) are located at the junction between a muscle and tendon.

Question 68

Intrafusal fibers receive input from

A) alpha motor neurons.
B) gamma motor neurons.
C) Ia sensory fibers.
D) C fibers.

Question 69

Without input from the gamma motor neurons,

A) extrafusal muscle fibers would be unable to contract.
B) intrafusal muscle fibers would not be able to relax.
C) extrafusal fibers would go limp whenever intrafusal fibers contracted.
D) intrafusal fibers would go limp whenever extrafusal fibers contracted.

Question 70

Muscle spindles are responsible for

A) providing feedback regarding muscle contraction.
B) providing feedback regarding position of joints.
C) providing feedback regarding muscle length.
D) contracting muscles.

Question 71

Which of the following statements correctly describes the spatial relationships of the extrafusal and intrafusal fibers?

A) The extrafusal and intrafusal fibers alternate with one another down the length of a muscle like beads on a string.
B) The intrafusal fibers are coiled tightly around the extrafusal fibers,allowing them to sense movement of the extrafusal fibers.
C) The extrafusal fibers lie perpendicular to the intrafusal fibers,so that stretch in one type will be balanced by stretch in the other type.
D) The extrafusal and intrafusal fibers lie parallel to one another,so that both will stretch simultaneously.

Question 72

Feedback regarding joint position and movement is provided by

A) muscle spindles.
B) mechanoreceptors.
C) Golgi tendon organs.
D) free nerve endings.

Question 73

Where should we look to find Ia sensory fibers?

A) at the neuromuscular junction where they are forming synapses with muscle fibers
B) wrapped around the middle sections of muscle spindles
C) in the junctions between muscles and tendons
D) in joints and in the skin

Question 74

The force of a movement is most directly controlled by

A) the rate of motor neuron firing alone.
B) recruitment of motor units alone.
C) feedback from muscle spindles and recruitment.
D) the rate of motor neuron firing and recruitment.

Question 75

Alpha motor neurons receive input from

A) muscle spindles only.
B) Golgi tendon organs only.
C) spinal interneurons only.
D) muscle spindles,Golgi tendon organs,and spinal interneurons.

Question 76

Recruitment proceeds in a way that ensures that the

A) least amount of energy and force possible will be used to do a job.
B) greatest amount of energy and force possible will be used to do a job.
C) fastest fibers will be recruited first to produce optimum reaction time.
D) fibers with the greatest oxygen requirements will be used only when absolutely necessary for survival.

Question 77

Golgi tendon organs provide feedback about

A) muscle stretch.
B) force.
C) position.
D) movement.

Question 78

Input from Ib sensory fibers

A) inhibits the activity of alpha motor neurons.
B) activates alpha motor neurons.
C) contracts muscle spindles.
D) contracts muscles.

Question 79

The cell bodies of alpha motor neurons are located _________ and each one enervates _________.

A) on the muscle;either fast or slow twitch fibers,but not both
B) in the brain;both fast and slow twitch fibers
C) in the spinal cord;both fast and slow twitch fibers
D) in the spinal cord;either fast or slow twitch fibers,but not both

Question 80

Golgi tendon organs are innervated by

A) Ia sensory fibers.
B) alpha motor neurons.
C) gamma motor neurons.
D) Ib fibers.