Deck 8: Movement

Question 1

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)control the heart and skeletal muscles 
D)control blood pressure and move the heart

Answer 1

C

Question 2

________ is a protein that makes up the thin filaments of myofibril.​ 

A)Pectin 
B)Myosin 
C)Actin 
D)Sarcomere

Answer 2

C

Question 3

The arrival of an action potential in a muscle fiber 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.

Answer 3

B

Question 4

The long strands of protein running the length of a muscle fiber are called​ 

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

Question 5

Action potentials in muscle fibers​ 

A)do not occur. 
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)lead to multiple twitches in that fiber.

Question 6

The separation of actin molecules from myosin molecules requires​ 

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

Question 7

Slow-twitch muscle fibers are to _______ as fast-twitch muscle fibers are to _______.​ 

A)Ia: Ib 
B)IIa; Ia 
C)I; IIa & IIb 
D)IIb; IIa

Question 8

The structure indicated by the number 3 in this image is  

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

Question 9

Nutrients are moved through the digestive tract by _________ muscle.​ 

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

Question 10

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.

Question 11

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 12

Muscle fibers respond to​ 

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

Question 13

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

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

Question 14

Slow-twitch fibers and fast-twitch fibers are both a type of​ 

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

Question 15

In a resting muscle fiber,_________ is covered by a protein called _________.​ 

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

Question 16

Single segments of a myofibril are called​ 

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

Question 17

A Z line is ​ 

A)a segment of myofibril. 
B)a type of muscle fiber. 
C)the boundary of a sarcomere. 
D)the path of a muscular action potential.

Question 18

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 19

The lungs are moved by _________ muscle​ 

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

Question 20

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 21

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 22

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

A)scar tissue. 
B)the breakdown of sarcomeres and Z lines. 
C)the production of more troponin. 
D)the production of more actin and myosin filaments.

Question 23

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 24

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)the number of ACTN3 genes that person has 
D)number of hours the individual spends each week engaged in aerobic activity, like running or cycling.

Question 25

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

A)alpha 
B)beta 
C)gamma 
D)theta

Question 26

Alpha motor neurons are​ 

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

Question 27

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

Question 28

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 responses. 
C)Firing rates increase, leading to uncomfortable cramping. 
D)Firing rates decrease, but muscle fibers are able to compensate for these changes.

Question 29

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

A)3 
B)8 
C)10 
D)12

Question 30

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 31

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

A)25 
B)30 
C)75 
D)90

Question 32

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 33

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

A)slow-twitch 
B)slow-twitch and fast-twitch 
C)fast-twitch 
D)autonomic

Question 34

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.

Question 35

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 III 
D)Type III; Type II

Question 36

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 37

Age-related changes in muscle function​ 

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

Question 38

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 39

Alpha motor neurons form connections with muscle fibers at the​ 

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

Question 40

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 41

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 42

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 43

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 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

Intrafusal fibers receive input from​ 

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

Question 46

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 47

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 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

Alpha motor neurons receive input from​ 

A)neurons in muscle spindles only. 
B)neurons in muscle spindles and Golgi tendon organs. 
C)spinal interneurons and neurons of the brainstem and motor cortex. 
D)neurons in muscle spindles and Golgi tendon organs, neurons of the brainstem and motor cortex, and spinal interneurons.

Question 50

Ia sensory fibers are activated in response to​ 

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

Question 51

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 spindle fibers 
C)in the junctions between muscles and tendons 
D)in joints and in the skin

Question 52

Intrafusal muscle fibers​ 

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

Question 53

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

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

Question 54

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 55

Extrafusal muscle fibers​ 

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

Question 56

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 57

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 58

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 59

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 60

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 61

Feedback regarding joint position and movement is provided by​ 

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

Question 62

Reciprocal inhibition is a simple type of _________ reflex.

A)monosynaptic. 
B) polysynaptic​ 
C)flexion 
D)withdrawal

Question 63

Golgi tendon organs are innervated by​ 

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

Question 64

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 65

The patellar tendon or "knee jerk" reflex is an example of a _________ reflex.​ 

A)withdrawal 
B)flexion 
C)monosynaptic 
D)polysynaptic

Question 66

Ventromedial pathways provide 

A)automatic control of the hands, feet, and parts of limbs farther from the body. 
B)automatic control of the neck, torso, and parts of limbs close to the body. 
C)voluntary control of the hands, feet, and the medial sections of limbs. 
D)voluntary control of the neck and torso.

Question 67

The rapid removal of your hand from a hot surface is the result of 

A)reciprocal inhibition. 
B) a monosynaptic reflex.​ 
C)an extensor reflex. 
D)a flexor reflex.

Question 68

Golgi tendon organs provide feedback about​ 

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

Question 69

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 70

Muscles that straighten joints are known as​ 

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

Question 71

Which of the following statements about muscle movement is true?​ 

A)The only thing that muscles can do is contract. 
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 cause movement by contracting and relaxing.

Question 72

The Babinski sign is 

A)normal in adults but not in children. 
B) normal in children but not adults.​ 
C)normal in both adults and children. 
D)abnormal in both adults and children.

Question 73

The preventing of one member of an antagonist pair of muscles whenever its partner is active is known as 

A)a monosynaptic reflex. 
B) a ​withdrawal reflex.  
C)a flexion reflex. 
D)reciprocal inhibition.

Question 74

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 75

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 76

The Babinski sign occurs when 

A)stroking the sole of the foot causes the toes to spread and the big toe to point upward. 
B) stroking the sole of the foot causes the toes to curl and then separate.​ 
C) tapping the knee with a small hammer causes the foot to kick.​ 
D) both extensors and flexors at a joint contract simultaneously in violation of reciprocal inhibition.​

Question 77

The lateral pathway originates in the _________ and controls _________ movements.

A)cerebral cortex; voluntary 
B) cerebral cortex; automatic​ 
C)brainstem; voluntary 
D)brainstem; automatic

Question 78

Rey was being evaluated for a possible spinal cord injury during a college football game.The team physician stroked the sole of Rey's foot,and his toes curled.This observation suggests that​ 

A)Rey has a serious spinal cord injury that might affect his future mobility. 
B)Rey has a mild spinal cord injury, and with proper treatment, he should recover completely. 
C)Rey does not appear to have damaged his spinal cord, although this should be confirmed by further testing. 
D)Rey's spinal cord is probably all right, but it appears that he has sustained damage to his foot or ankle.

Question 79

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 80

Elizabeth's grandmother recently underwent a hip replacement operation.Because she took this course,Elizabeth is able to tell her grandmother that she 

A)will need to be very careful, because the removal of her joint receptors means that she will not know the position of her hip without looking. 
B)will have to relearn how to walk, as the operation removes joint receptors responsible for managing muscle stretch. 
C)will still know the position of her hip without looking, even though her operation will remove all of her joint receptors. 
D)should prepare to deal with phantom pain from the joint receptors that have been removed.