Deck 8: Control of Movement

Question 1

The function of intrafusal muscle fibers is to

A) detect changes in the muscle fiber length.
B) stimulate the muscle to contract.
C) limit the degree of contraction of the muscle.
D) coordinate the contraction of extensor and flexor muscles.
E) detect how hard the muscle is pulling.

Answer 1

A

Question 2

The number of muscle fibers served by a single axon varies considerably. In muscles that move the fingers, the ratio is small, whereas in muscles that move the legs, the ratio is large. This difference in ratio depends upon the ______________ needed to move the muscle.

A) precision
B) strength
C) flexibility
D) speed
E) agility

Answer 2

A

Question 3

Motor unit size can vary in the body. In the finger, the motor unit size is most likely

A) less than 1 to 10.
B) 1 to 40.
C) 1 to 100.
D) 1 to 500.
E) more than 1 to 500

Answer 3

A

Question 4

The firing rate of the ________ determines the strength of contraction of a muscle.

A) intrafusal muscle fibers
B) Golgi tendon organs
C) afferent fibers
D) gamma motor neurons
E) alpha motor neurons

Question 5

Alpha motor neurons send information to

A) intrafusal muscle fibers.
B) extrafusal muscle fibers.
C) muscle spindles.
D) gamma motor neurons.
E) alpha motor neurons.

Question 6

Flexion refers to

A) detection in the changes in the muscle fiber length.
B) movement of a limb away from the body.
C) inhibiting the degree of contraction of the muscle.
D) drawing in of a limb toward the body.
E) growth of muscle fibers with repeated use.

Question 7

The ________ is formed by the synapse of an efferent nerve terminal onto a muscle fiber.

A) myofibril tangle
B) motor unit
C) neuromuscular junction
D) intrafusal contact
E) muscle spindle

Question 8

The presence of dark stripes in skeletal muscles is due to

A) the presence of blood vessels within the muscle fibers.
B) thickened membranes at the neuromuscular junctions.
C) variations in myelin coating of the muscle fibers.
D) overlapping segments of actin and myosin filaments.
E) alternating motor units.

Question 9

Bodybuilders show off their muscles by

A) activating their autonomic nervous system.
B) willing the activation of their extensor muscles.
C) willing the activation of their flexor muscles.
D) simultaneously contracting their flexor and extensor muscles.
E) ingesting large amounts of sympathomimetic drugs.

Question 10

A motor unit size of one axon per 10 extrafusal fibers might be expected in the ________ muscles.

A) elbow
B) wrist
C) eye
D) leg
E) forearm

Question 11

Moving a limb to the body is _________, whereas moving a limb away from the body is ______________.

A) flexion; extension
B) extension; flexion
C) contraction; extension
D) flexion; contraction
E) reduction; contraction

Question 12

Muscle contraction occurs when the myosin cross bridges row along the length of the ______ filaments.

A) myosin
B) actin
C) intrafusal
D) extrafusal
E) myofibril

Question 13

Our body movements are mediated by the contraction of _______ muscle.

A) intrafusal
B) skeletal
C) cardiac
D) smooth
E) non-striated

Question 14

The function of the gamma motor neuron is to

A) detect changes in the muscle fiber length.
B) stimulate the muscle to contract.
C) limit the degree of contraction of the muscle.
D) coordinate the contraction of extensor and flexor muscles.
E) control the sensitivity of the muscle spindle.

Question 15

The neurotransmitter of the neuromuscular junction is

A) dopamine.
B) GABA.
C) glutamate.
D) glycine.
E) acetylcholine.

Question 16

Another name for the muscle spindles is

A) intrafusal muscle fibers.
B) Golgi tendon organs.
C) afferent fibers.
D) gamma motor neurons.
E) alpha motor neurons.

Question 17

Myosin cross bridges attach to actin strands, bend, detach, and then attach lower. These actions result in the __________ of the muscle fibers.

A) shortening
B) lengthening
C) activating
D) elongating
E) stretching

Question 18

The event(s) that induce the contraction of a muscle fiber is/are the

A) entry of calcium ions into the cytoplasm of the muscle fiber.
B) entry of chloride ions into the cytoplasm of the muscle fiber.
C) release of acetylcholine onto the postsynaptic membrane.
D) separation of the actin and myosin filaments.
E) movement of potassium ions into the muscle fiber.

Question 19

Which of the following is true of skeletal muscle?

A) Contraction of skeletal muscle can alter blood flow through the heart.
B) Skeletal muscle contraction produces movements of the body.
C) Skeletal muscles pump blood throughout the body.
D) Flexion of a skeletal muscle causes limbs to move outward from the body.
E) Extensors are skeletal muscles that cause limbs to draw in to the body.

Question 20

A ________ consists of the extrafusal fibers innervated by a single alpha motor neuron.

A) myofibril tangle
B) motor unit
C) extrafusal junction
D) intrafusal contact
E) muscle spindle

Question 21

Reflex circuits

A) typically involve thousands of neurons.
B) typically involve one chain of neurons.
C) typically involve dozens of neurons.
D) always involve the brain.
E) involve one neuron.

Question 22

An important function of the monosynaptic stretch reflex is to

A) coordinate the movements of the flexors on each limb.
B) smooth out muscle contractions.
C) provide feedback to the brain about motor activity.
D) alter the speed with which an arm moves while throwing a ball.
E) help maintain posture.

Question 23

Less sensitive afferent axons from the Golgi tendon organ trigger a reaction that results in glycine release and

A) the production of excitatory postsynaptic potentials.
B) the production of inhibitory postsynaptic potentials.
C) an increase in the likelihood that the next cell will fire.
D) an increase in neurotransmitter release.
E) a depolarization.

Question 24

Which neuroscientist stimulated human cortex to map the motor cortex?

A) Broca
B) Fluorens
C) Penfield
D) Helmholtz
E) Fritsch

Question 25

The monosynaptic stretch reflex circuit consists of

A) muscle spindle - spinal cord - alpha motor neuron - extrafusal muscle fibers
B) spinal cord - muscle spindle - alpha motor neuron - extrafusal muscle fibers
C) extrafusal muscle fibers - alpha motor neuron - spinal cord - muscle spindle
D) muscle spindle - spinal cord - extrafusal muscle fibers - alpha motor neuron
E) spinal cord - alpha motor neuron - extrafusal muscle fibers - muscle spindle

Question 26

Muscle tension is sensed by ________, whereas muscle fiber length is sensed by ________.

A) extrafusal fibers; Golgi tendon organs
B) intrafusal fibers; extrafusal fibers
C) Golgi tendon organs; intrafusal fibers
D) motor neurons; intrafusal fibers
E) multiunit fibers; myofibrils

Question 27

The vertical patch of cortex located rostral to the central sulcus is known as the

A) primary visual cortex.
B) prefrontal cortex.
C) temporal association cortex.
D) primary motor cortex.
E) primary somatosensory cortex.

Question 28

Relaxation of your arm would be expected to lengthen the extrafusal fibers. This would in turn lead to a(n) ________ firing rate of the ________.

A) increased; GTO fibers
B) increased; muscle spindles
C) decreased; GTO fibers
D) decreased; muscle spindles
E) decreased; alpha motor neurons

Question 29

Which of the following is an example of a polysynaptic reflex?

A) the patellar reflex
B) the withdrawal of a limb in response to pain
C) secretion of saliva
D) the monosynaptic stretch reflex
E) contraction of a muscle induced by application of electrical current to the muscle

Question 30

_____________________ contain receptors that code for stretch.

A) Extrafusal fibers and Golgi tendons
B) Golgi tendon organs
C) Intrafusal fibers and extrafusal fibers
D) Intrafusal fibers and Golgi tendons
E) Extrafusal fibers

Question 31

If asked to move your leg, this response takes longer to complete than if you move your leg in response to what feels like a spider crawling on it. When you respond to the imaginary spider, this response

A) is reflexive and does not need to be processed deeply to be performed.
B) is planned and requires deeper processing to be performed.
C) is unpredictable and requires deeper processing to be performed.
D) is reflexive and requires deeper processing to be performed.
E) is planned and does not need to be processed deeply to be performed.

Question 32

Which of the following is true of the motor homunculus?

A) Damage to a part of the motor homunculus on one side of the brain would impair motor function of the entire body on the same side as the damage.
B) The homunculus represents the specific body muscle groups that are controlled by specific regions of the cortex.
C) The homunculus represents the specific body parts that send afferent signals to a specific region of the cortex.
D) There is only one homunculus in the human brain.
E) The homunculus depicts sensory function.

Question 33

The disproportionate cortical representation in the primary motor cortex of the fingers and mouth is due to the fact that

A) the hands and mouth take more innervation to move.
B) are less sensitive than other areas of the body.
C) are more sensitive than other areas of the body.
D) require greater precision of movement.
E) require less precision of movement.

Question 34

The neurons of the primary motor cortex receive important inputs from the

A) pons.
B) amygdala.
C) tertiary somatosensory cortex.
D) basal ganglia.
E) medulla.

Question 35

The primary motor cortex receives information from

A) the supplementary motor area.
B) the premotor cortex.
C) the prefrontal cortex and the supplementary motor area.
D) the supplementary motor area and the premotor cortex.
E) prefrontal and premotor cortices.

Question 36

An indirect way through which the brain modulates muscle tension is to

A) alter the firing rate in the gamma motor system.
B) induce presynaptic inhibition.
C) block the release of acetylcholine into the junction.
D) excite the Golgi tendon organs.
E) inhibit the monosynaptic stretch reflex.

Question 37

The physical effects of a muscle twitch last longer than the action potential that triggered the contraction because

A) muscle fibers lack elasticity.
B) it takes time to extrude calcium ions out of the fiber.
C) the acetylcholine molecules are slowly cleared from the neuromuscular junction.
D) the twitches run back and forth along the muscle fiber.
E) muscle fibers are thicker than axons.

Question 38

________ is a spatial representation of the specific cortical areas that control specific body movements.

A) motor homunculus
B) choreogram
C) somatogram
D) corticotopic map
E) audiogram

Question 39

Depolarization of the muscle fiber opens voltage-gated ______ channels, which trigger contractions.

A) Ca⁺⁺
B) Na⁺
C) K⁺
D) Cl^-
E) Mg⁺

Question 40

The functional significance of the Golgi tendon organs is to

A) allow us to lift heavy loads.
B) reduce muscle relaxation.
C) maintain muscle tone.
D) simultaneously contract flexor and extensor muscles.
E) prevent the tearing of muscle fibers from a tendon.

Question 41

The pontine and dentate nuclei are located in the

A) reticular formation.
B) pons.
C) cerebellum.
D) medulla.
E) cortex.

Question 42

The ________ functions in the control of movements of the upper legs and the trunk.

A) lateral corticospinal tract
B) ventral corticospinal tract
C) spinothalamic tract
D) rubrospinal tract
E) corticobulbar pathway

Question 43

The corticospinal tract, the corticobulbar tract, and the rubrospinal tract make up the ______________ of descending tracts from the primary motor cortex.

A) lateral group
B) ventromedial group
C) caudal group
D) posteromedial group
E) rostral group

Question 44

Damage involving the ________ tract would be expected to impair walking as well as automatic functions such as breathing and sneezing.

A) lateral corticospinal
B) corticospinal
C) tectospinal
D) reticulospinal
E) premotor-striatal

Question 45

A key motor function of the reticular formation is to

A) directly excite spinal cord alpha motor neurons.
B) facilitate movements through inhibition of the internal division of the globus pallidus.
C) excite noradrenergic neurons within the substantia nigra.
D) control muscle tone through the gamma motor system.
E) control the activity of the cerebellum.

Question 46

Damage involving the ________ tract would be expected to impair your ability to grasp and manipulate objects with your fingers.

A) lateral corticospinal
B) vestibulospinal
C) tectospinal
D) reticulospinal
E) premotor-striatal

Question 47

Imaging studies indicate strong activation of the pre-SMA region during

A) random hand movements.
B) performance of a learned sequence of button presses.
C) movement of the eyes.
D) planning of motor movements.
E) scanning a screen for visual cues.

Question 48

The ____________ are responsible for the decision to move.

A) posterior parietal cortex and frontopolar cortex
B) pre-SMA and posterior parietal cortex
C) posterior SMA and posterior parietal cortex
D) pre-SMA and frontopolar cortex
E) frontopolar cortex and posterior SMA

Question 49

Damage to the ________________ resulted in monkeys being unable to perform a once familiar response, specifically pushing in a lever and then turning it to the left. This result suggests that this brain area is involved in executing well-learned sequences of motor responses.

A) supplementary motor area
B) premotor cortex
C) frontorbital cortex
D) common integrative area
E) primary motor cortex

Question 50

Electrical stimulation of the mesencephalic region located ventral to the inferior colliculus in the cat will

A) awaken a sleeping cat.
B) alter the sitting posture of a cat.
C) reinforce behaviors that produce this stimulation.
D) directly excite spinal cord motor neurons in the cat.
E) induce a cat to make pacing movements.

Question 51

Damage involving the ________ tract would be expected to impair posture.

A) lateral corticospinal
B) vestibulospinal
C) tectospinal
D) reticulospinal
E) premotor-striatal

Question 52

Patterns of firing of neurons in the ________ precede by 10 seconds the decision to make a motor response.

A) frontopolar cortex
B) premotor cortex
C) corpus callosum
D) cerebellum
E) secondary somatosensory cortex

Question 53

The ________ controls movements of the upper legs and trunk.

A) lateral corticospinal tract
B) ventral corticospinal tract
C) spinothalamic tract
D) rubrospinal tract
E) corticobulbar pathway

Question 54

In the two groups of descending tracts in the motor system, neurons of the ________ control the movements of the body trunk, whereas neurons of the ________ control movements of the hands and fingers.

A) ventromedial group; lateral group
B) primary motor cortex; secondary motor cortex
C) lateral group; ventromedial group
D) premotor cortex; nigrostriatal bundle
E) secondary motor cortex; primary motor cortex

Question 55

A key function of the rubrospinal tract is to

A) interconnect the spinal cord with the substantia nigra.
B) modulate the activity of the ventromedial group.
C) control the movements of the eyes to a moving stimulus.
D) control the independent movements of the forearms and hands.
E) provide the motivation for movement.

Question 56

A key function of premotor cortex is to

A) allow an organism to learn to respond to an arbitary visual clue with a learned, specific movement.
B) facilitate the performance of a series of movements.
C) evoke the desire to perform a movement.
D) allow an organism to learn to respond with a specific movement to a nonarbitrary visual cue.
E) modulate the activity of the basal ganglia and limbic system.

Question 57

The ________ controls the muscles of the limbs and fingers.

A) lateral corticospinal tract
B) ventral corticospinal tract
C) spinothalamic tract
D) rubrospinal tract
E) corticobulbar pathway

Question 58

The ________ controls movements of the tongue, face, and some eye muscles.

A) lateral corticospinal tract
B) ventral corticospinal tract
C) spinothalamic tract
D) rubrospinal tract
E) corticobulbar tract

Question 59

The lateral corticospinal tract helps to control

A) the arms.
B) the arms and hands.
C) the feet.
D) the arms, hands, and fingers.
E) the arms, hands, fingers, and feet.

Question 60

Stimulation of the pre-SMA cortex induces

A) automatic movements.
B) a visual sensation.
C) the strong urge to make a movement.
D) mild motor seizures.
E) suppression of motor function.

Question 61

A person with damage to the cerebellum would be expected to show

A) sympathetic apraxia.
B) difficulty in arising from a sitting position.
C) jerky, uncoordinated movements.
D) improvements in posture.
E) tremor at rest.

Question 62

The hyperdirect pathway involves excitatory input from the ________ that rapidly inhibits motor behavior.

A) amygdala
B) pre-SMA
C) parietal cortex
D) globus pallidus
E) primary motor cortex

Question 63

Parkinson's disease is characterized by

A) impaired ability to follow a map.
B) sudden involuntary movements.
C) slowness of movement.
D) an inability to perform a sequence of movements.
E) a gene mutation on chromosome 4.

Question 64

The cerebellar ________ receives somatosensory information and influences the vestibulospinal and reticulospinal tracts.

A) dentate nucleus
B) pontine nucleus
C) vermis
D) flocculonodular node
E) intermediate and lateral zones

Question 65

The net overall effect of the indirect pathway between the basal ganglia and the motor cortex through ________ is ________ for motor movement.

A) GPi; excitatory
B) GPi; inhibitory
C) GPe; excitatory
D) the hypothalamus; excitatory
E) the substantia nigra; inhibitory

Question 66

Our ability to mimic the motor actions of others depends on ________ neurons within area ________.

A) mirror; V2
B) decision; V1
C) mirror; V5
D) mirror; F5
E) decision; F5

Question 67

Which of the following is a key characteristic of Parkinson's disease?

A) ballistic movements of the limbs
B) difficulty in sitting in a chair
C) tremor during rapid motor movements
D) slowness of movement
E) excessive movement of the tongue and lips

Question 68

The direct pathway between the basal ganglia and the motor cortex is ________ for motor movement, whereas the overall effect of the indirect pathway is ________.

A) excitatory; inhibitory
B) inhibitory; excitatory
C) excitatory; excitatory
D) inhibitory; inhibitory
E) required; not required

Question 69

A primary symptom of Huntington's disease is

A) akinesia.
B) dystonias.
C) tremor at rest.
D) difficulty initiating movement.
E) uncontrollable movements.

Question 70

The key nuclei of the basal ganglia include the

A) caudate, putamen, and globus pallidus.
B) substantia nigra.
C) putamen and ventral tegmental area.
D) globus pallidus and hippocampus.
E) hippocampus and amygdala.

Question 71

The basal ganglia receive some level of input from

A) the primary motor cortex.
B) the temporal cortex.
C) the hippocampus.
D) the association cortex.
E) all regions of the cortex.

Question 72

The key outputs of the basal ganglia are to the

A) primary motor cortex.
B) temporal cortex.
C) orbitofrontal cortex.
D) association cortex.
E) parietal cortex.

Question 73

Emma watches her mom putting on cosmetics. She picks up a tube of lip gloss as her mom puts her own lipstick on. Emma imitates the movements, putting lip gloss on her own lips. It is likely that Emma's __________ are activated during this process.

A) imitative neurons
B) occipital neurons
C) fusiform face area neurons
D) decision neurons
E) mirror neurons

Question 74

Mirror neurons are located in the ______________ premotor cortex.

A) ventral
B) dorsal
C) rostral
D) caudal
E) posterior

Question 75

The sound of a bag being ripped open is likely to trigger activation of the

A) mirror neurons.
B) audiovisual neurons.
C) occipital neurons.
D) imitative neurons.
E) fusiform face area neurons.

Question 76

P. exhibited a problem in ________ due to _______.

A) starting a leg movement; frontal cortex damage
B) posture; prior cocaine usage
C) stopping an arm movement; cerebellar damage
D) eye-tracking; Parkinson's disease
E) stopping an arm movement; frontal cortex damage

Question 77

Parkinson's disease results from loss of ________-secreting neurons of the ________.

A) GABA; perifornical bundle
B) dopamine; nigrostriatal bundle
C) serotonin; corticospinal tract
D) acetylcholine; mesolimbic pathway
E) CCK; ventromedial group

Question 78

Damage to the flocculonodular lobe of the cerebellum would be expected to impair

A) muscle contractions.
B) postural reflexes.
C) composition of movements.
D) timing of ballistic movements.
E) planning of movements.

Question 79

Degeneration of neurons within the ________ results in loss of ________ function and Huntington's disease.

A) caudate and putamen; GABAergic
B) globus pallidus; dopaminergic
C) frontal cortex; cholinergic
D) pons; GABAergic
E) nigrostriatal bundle; dopamine

Question 80

Which of the following is true of the cerebellum?

A) The cerebellum consists of two hemispheres.
B) The cerebellum sends outputs to the spinal cord.
C) The cerebellum is involved in the control of eye movements.
D) The cerebellum contains fewer neurons than does the cerebral cortex.
E) The cerebellum contains about 500 billion neurons.