Deck 10: Control of Body Movement

Question 1

Stretch reflexes

A)Occur only in the legs
B)Are important for maintaining erect posture
C)Mediate flexor withdrawal from a painful stimulus
D)Are initiated by stimulation of Golgi tendon organs
E)Are described by all of the choices

Answer 1

B

Question 2

Normal motor control requires that the basal nuclei

A)Provide a perceptual awareness related to specific sensory inputs from the eyes, nose and mouth
B)Provide a general perceptual awareness associated with general somatosensory inputs from the skin, muscles and joints
C)Provide a sense of the cause and effect relationships between one's actions and the consequences of taking these actions - before executing them
D)Participate in a looping neuronal circuit through which motor impulses are sent to facilitate or suppress movements
E)Both provide a perceptual awareness related to specific sensory inputs from the eyes, nose and mouth and provide a general perceptual awareness associated with general somatosensory inputs from the skin, muscles and joints are correct

Answer 2

D

Question 3

Golgi tendon organs

A)Are located in the tendons joining muscle and bone
B)Monitor the strength of muscle contractions
C)Are associated with monosynaptic reflexes
D)Both are located in the tendons joining muscle and bone and monitor the strength of muscle contractions are correct
E)All of the choices are correct

Answer 3

D

Question 4

Local interneurons controlling the firing of motor neurons

A)Receive input from receptors in the muscle that is innervated by the motor neurons
B)Receive information from muscles that are antagonistic to the one innervated by the motor neurons
C)May be inhibitory
D)Both receive input from receptors in the muscle that is innervated by the motor neurons and receive information from muscles that are antagonistic to the one innervated by the motor neurons are correct
E)Do all of these things

Question 5

Which of the following statements is true with regard to control of body movement?

A)The highest level of the hierarchy of motor control includes the frontal lobe cortex, the primary motor cortex and the basal ganglia
B)The highest level of the hierarchy of motor control is composed entirely of areas of cerebral cortex
C)The middle level of the hierarchy of motor control assembles programs or patterns of activity and then monitors them as the movement is carried out
D)Both the highest level of the hierarchy of motor control includes the frontal lobe cortex, the primary motor cortex and the basal ganglia and the highest level of the hierarchy of motor control is composed entirely of areas of cerebral cortex are true
E)Both the highest level of the hierarchy of motor control is composed entirely of areas of cerebral cortex and the middle level of the hierarchy of motor control assembles programs or patterns of activity and then monitors them as the movement is carried out are true

Question 6

The phenomenon in skeletal muscle known as muscle tone

A)Is related to the passive elasticity exhibited by the anatomical components of the whole muscle
B)Is related directly to a continuous low level of alpha motor neuron signaling
C)Is the lack of extensibility observed at any given moment in the tendons found at both the origin and insertion of the muscle
D)Both is related to the passive elasticity exhibited by the anatomical components of the whole muscle and is related directly to a continuous low level of alpha motor neuron signaling are correct
E)Both is related directly to a continuous low level of alpha motor neuron signaling and is the lack of extensibility observed at any given moment in the tendons found at both the origin and insertion of the muscle are correct

Question 7

Intrafusal muscle fibers

A)Are found in muscle spindles
B)Are innervated by alpha motor neurons
C)Generate most of the tension in a skeletal muscle
D)Fire continuously at a constant rate
E)Both are found in muscle spindles and generate most of the tension in a skeletal muscle are correct

Question 8

The basal ganglia

A)Receive input from the sensorimotor cortex
B)Form information loops with the sensorimotor cortex and the hypothalamus
C)Form information loops with the sensorimotor cortex and the thalamus
D)Both receive input from the sensorimotor cortex and form information loops with the sensorimotor cortex and the hypothalamus are correct
E)Both receive input from the sensorimotor cortex and form information loops with the sensorimotor cortex and the thalamus are correct

Question 9

Which of the following occurs as a result of tapping one's patellar tendon?

A)Alpha motor neurons stimulate contraction of intrafusal fibers in extensor muscles
B)Alpha motor neurons stimulate contraction of extrafusal fibers in extensor muscles
C)Alpha motor neurons that innervate ipsilateral flexor muscles are inhibited
D)Both alpha motor neurons stimulate contraction of intrafusal fibers in extensor muscles and alpha motor neurons that innervate ipsilateral flexor muscles are inhibited are correct
E)Both alpha motor neurons stimulate contraction of extrafusal fibers in extensor muscles and alpha motor neurons that innervate ipsilateral flexor muscles are inhibited are correct

Question 10

The crossed-extensor reflex in a limb

A)Is initiated by a painful stimulus in the ipsilateral limb
B)Stimulates contraction of the contralateral extensor and inhibits contraction of the contralateral flexor
C)Accompanies the stretch reflex
D)Both is initiated by a painful stimulus in the ipsilateral limb and stimulates contraction of the contralateral extensor and inhibits contraction of the contralateral flexor are correct
E)All of the choices are correct

Question 11

Which of the following does not describe the highest hierarchical level of motor control? It

A)Includes the premotor area
B)Includes the supplementary motor area
C)Includes association cortex in the frontal and parietal lobes
D)Includes limbic-system structures
E)Directs "what to do" and "when to do it."

Question 12

Which of the following statements regarding disorders of body movement is/are correct?

A)In Parkinson's disease, input from the basal ganglia to the thalamus is impaired
B)Symptoms of Parkinson's disease include impairment of the ability to initiate voluntary movement
C)Symptoms of damage to the cerebellum include difficulty in maintaining balance while walking
D)Both in Parkinson's disease, input from the basal ganglia to the thalamus is impaired and symptoms of Parkinson's disease include impairment of the ability to initiate voluntary movement are correct
E)All of the choices are correct

Question 13

Which of the following statements regarding control of body movement is correct?

A)The basal ganglia receive input from dopaminergic neurons of the substantia nigra
B)The cerebellum is important for the initiation of body movement
C)The basal ganglia form part of the corticospinal pathways
D)The skeletal muscles of the body are represented in the primary motor cortex proportionately to their size
E)None of the choices are correct

Question 14

Which of the following would be a consequence of touching a hot object with one's right hand?

A)A stretch reflex would be triggered that would cause contraction of extensor muscles in the right arm
B)A withdrawal reflex would be triggered by nociceptors that would stimulate contraction of flexor muscles in the right arm
C)Reflex mechanisms would inhibit contraction of the extensor muscles of the right arm
D)Both a stretch reflex would be triggered that would cause contraction of extensor muscles in the right arm and a withdrawal reflex would be triggered by nociceptors that would stimulate contraction of flexor muscles in the right arm would be consequences
E)Both a withdrawal reflex would be triggered by nociceptors that would stimulate contraction of flexor muscles in the right arm and reflex mechanisms would inhibit contraction of the extensor muscles of the right arm would be consequences

Question 15

The flexor (withdrawal)reflex

A)Has a monosynaptic component
B)Is initiated by stretching muscle spindle fibers
C)Is initiated by stimulation of the Golgi tendon organ
D)Stimulates contraction of the ipsilateral flexor muscle and inhibits contraction of the ipsilateral extensor muscle
E)Both has a monosynaptic component and is initiated by stretching muscle spindle fibers are correct

Question 16

Symptoms of Parkinson's disease include

A)Flaccid paralysis
B)Intention tremor
C)Resting tremor
D)Both flaccid paralysis and intention tremor
E)Both flaccid paralysis and resting tremor

Question 17

Reflexes triggered by the activation of muscle spindles

A)Have a monosynaptic component
B)Result in activation of alpha and gamma motor neurons
C)Result in the contraction of muscle spindle fibers
D)Include the "knee jerk" reflex
E)Do all of these things

Question 18

The fibers in a muscle spindle

A)Are not true muscle fibers because they cannot contract
B)Are innervated by gamma motor neurons
C)Function to maintain tension on spindle receptors
D)Both are innervated by gamma motor neurons and function to maintain tension on spindle receptors are correct
E)All of the choices are correct

Question 19

According to the hierarchy of motor control,

A)The highest level of control consists entirely of areas of cerebral cortex
B)The middle level of control contains no areas of cerebral cortex
C)The lowest level of control includes the cerebellum and basal ganglia
D)Structures in the middle level receive information from both the highest and the lowest levels of the hierarchy
E)Afferent information from skin, joint and muscle receptors has little influence on body movement

Question 20

The contraction of intrafusal muscle fibers

A)Shortens the muscle spindle
B)Is important for the detection of extrafusal muscle relaxation
C)Is stimulated by gamma motor neuron activation
D)Both shortens the muscle spindle and is important for the detection of extrafusal muscle relaxation are correct
E)Both shortens the muscle spindle and is stimulated by gamma motor neuron activation are correct

Question 21

Receptors of the postural reflexes include

A)Rods and cones
B)Hair cells
C)Muscle spindles and other proprioceptors
D)Rods and cones and muscle spindles and other proprioceptors
E)All of the choices are correct

Question 22

Afferent information about body movement is integrated at the level of the interneurons controlling the firing of motor neurons.

Question 23

The fewer motor neurons of a given motor neuron pool that are activated,the finer is the control of muscle movement.

Question 24

In Parkinson's disease,

A)Input from the substantia nigra to the basal ganglia is impaired
B)Ability to suppress unwanted movement is impaired
C)Ability to make voluntary movements is not impaired
D)Both input from the substantia nigra to the basal ganglia is impaired and ability to suppress unwanted movement is impaired are correct
E)All of the choices are correct

Question 25

Implantation of electrodes into the substantia nigra/basal nuclei region as a treatment for Parkinson's disease is intended to deliver an electrical shock in order to ______ which will produce more normal voluntary executive motor function.

A)Provide release of surrogative dopamine receptor agonists
B)Inhibit the activity of normal dopamine degrading enzymes
C)Activate precursor dopamine synthesizing metabolic pathways
D)Destroy regions of the basal nuclei and substantia nigra which are overproducing dopamine
E)Stimulate the production and release of dopamine

Question 26

In Parkinson's disease,the specific cause of difficulty is the

A)Enhanced sensitivity of cholinergic receptors to acetylcholine
B)Reduced ability of neurons in the substantia nigra to release dopamine
C)Failure of serotonin receptors to bind with these neurohormones
D)Hyperactivity of metabolic enzymes that degrade dopamine
E)Natural tendency of basal nuclei to follow a daily recurring, oscillating cycle of rising and falling norepinephrine release

Question 27

Which of the following is not true of corticospinal fibers? They

A)May synapse directly on alpha motor neurons
B)May synapse directly on gamma motor neurons
C)May synapse directly on interneurons
D)Generally affect large groups of muscles
E)May synapse with afferent neurons in ascending pathways

Question 28

The corticospinal pathways

A)Are descending motor pathways
B)Begin in the cortex of the cerebellum
C)Consist of many interneurons linked synaptically
D)Both are descending motor pathways and begin in the cortex of the cerebellum are correct
E)All of the choices are correct

Question 29

Which of the following symptoms is common following damage to the cerebellum?

A)Flaccid paralysis
B)Violent, uncontrolled body movements called chorea
C)Intention tremor
D)Both flaccid paralysis and violent, uncontrolled body movements called chorea are common
E)Both violent, uncontrolled body movements called chorea and intention tremor are common

Question 30

During motor activity,alpha-gamma coactivation provides important information regarding muscle length to the higher motor control centers.

Question 31

The cyclic pattern of movement that results in walking is

A)"wired in" at the level of the brain stem and spinal cord
B)Controlled by central pattern generators
C)Independent of control from higher brain areas
D)"wired in" at the level of the brain stem and spinal cord and controlled by central pattern generators
E)"wired in" at the level of the brain stem and spinal cord and independent of control from higher brain areas

Question 32

Inhibitory input to motor neurons is as important for normal muscle function as excitatory input.

Question 33

Once a planned movement is under way,it is usually carried out with no further modifications until it is finished.

Question 34

The motor neuron pool of a skeletal muscle comprises the innervation of all of the motor units of that muscle.

Question 35

The cerebellum

A)Helps to coordinate body movements
B)Is important in maintaining posture
C)Receives no input from sensory pathways
D)Both helps to coordinate body movements and is important in maintaining posture are correct
E)All of the choices are correct

Question 36

Practicing a movement allows for "fine tuning" the original program so that the movement can be executed with fewer corrections.

Question 37

Which of the following statements about control of body movement is true?

A)The corticospinal motor pathways control most fine, discrete muscle activity
B)The brain stem pathways control postural and most other coordinated body movements
C)The cerebellum fine-tunes ongoing movement and helps to coordinate movements
D)Both the corticospinal motor pathways control most fine, discrete muscle activity and the brain stem pathways control postural and most other coordinated body movements are true
E)All of the choices are true

Question 38

Muscle tone

A)Is defined as the resistance of muscle to continuous passive stretch
B)Is absent in a normal relaxed limb
C)Increases as a relaxed person becomes alert
D)Both is defined as the resistance of muscle to continuous passive stretch and is absent in a normal relaxed limb are correct
E)Both is defined as the resistance of muscle to continuous passive stretch and increases as a relaxed person becomes alert are correct

Question 39

Afferent fibers from muscle-spindle stretch receptors in a muscle make excitatory synaptic contact with motor neurons that innervate the extrafusal fibers of the same muscle.

Question 40

Information from the muscle-spindle stretch receptors is not conveyed above the level of the spinal cord and thus does not reach consciousness.

Question 41

One of the primary roles of the cerebellum is to compare a given program for movement with the actual movement as it occurs and to make adjustments in the movement and in the program.

Question 42

The activity of alpha motor neurons innervating an extensor muscle can be inhibited by activation of the Golgi tendon organs near the muscle.

Question 43

Motor pathways extending from the central nervous system to muscle fibers are subject to control by both excitatory or inhibitory interneurons.

Question 44

Stimulation of a Golgi tendon organ causes a reflex contraction of the muscle whose tension the receptor is monitoring.

Question 45

The thalamus is an important relay station for feedback of information to the basal ganglia from the motor cortex.

Question 46

Motor neurons which innervate skeletal muscle fibers are subject to the summative effects of interneurons firing either excitatory,inhibitory or both kinds of neurotransmitters simultaneously.

Question 47

In the primary motor cortex,representation of the left half of the body is primarily on the right side of the brain.

Question 48

In general,the brain stem descending pathways have greater influence over motor neurons controlling muscles involved in fine movements and the corticospinal pathways are more involved in the coordination of large muscle groups and postural muscles.

Question 49

When a person steps on a tack with the left foot,flexor muscles on the right leg and extensor muscles on the left leg will be stimulated to contract.

Question 50

Crossed-extensor reflexes,but not stretch reflexes,are important postural reflexes.

Question 51

Excitatory and inhibitory interneurons are activated to release their particular neurotransmitters,only upon sufficient sensory action potentials conveyed from sensory receptors associated with muscle tension,the states of activity in muscles and joints in addition to various regions of the skin.

Question 52

The skeletal muscles of the body are represented in the primary motor cortex proportionately to their size.