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Flashcards in Brain Controlled Motor Output Deck (85)
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1
Q

In reflex situations, sensory inputs info to ______ via _____

A

somatic motor neurons, direct or indirect input

2
Q

Direct sensory input comes from…

A

1a afferents of muscle spindle

- stretch reflex

3
Q

Indirect sensory input comes from…

A

interneurons from various areas of brain

4
Q

In nonreflex situations, sensory/limbic/frontal lobe input triggers…

A

central preprocessing w/in the supplemental and premotor cortices

5
Q

Triggering of central preprocessing results in…

A

motor plan implemented by commands transmitted from primary motor cortex

6
Q

Successful execution of central preprocessing depends on…

A

feedback via somatosensory cortex information and visual pathway

7
Q

Motor processing is also provided by the…

A

cerebellum and basal ganglia

8
Q

NS output regulates:

A
  • which muscle fibers will be stimulated to contract

- contractile force of skeletal muscles (somatic motor activity)

9
Q

Planning of motor output involves…

A

many areas of the posterior region of the frontal lobe

10
Q

Examples of input for motor output:

A
  • motivational factors from limbic system
  • planning from premotor cortex and supplemental motor complex
  • sensory information from parietal cortex
  • subcortical processing in cerebellum and basal ganglia
11
Q

Premotor cortex is located in…

A

frontal lobe rostral (in front of) primary motor cortex

12
Q

Functions of premotor cortex:

A
  • designs movements to do desired tasks
  • active in planning and execution of movement
  • sends output to primary motor cortex to control simple tasks of distal limb muscles
  • has Broca’s area: important in word formation
13
Q

Premotor cortex mainly controls…

A
  • axial muscles for posture
14
Q

Impulses to axial muscles are carried in the…

A

anterior corticospinal tract

15
Q

Supplemental motor areas are located…

A

anterosuperior to premotor cortex

16
Q

Functions of supplemental motor areas:

A
  • planning of complex bilateral movements
  • work w/ premotor and primary motor cortex
  • involved in vocalization and complex postural movements
17
Q

Primary motor cortex is located on the…

A

precentral gyrus of frontal lobe

18
Q

Primary motor cortex is only involved in…

A

execution of movement

19
Q

Primary motor cortex receives input from…

A
  • premotor regions
  • supplemental regions
  • sensory proprioceptors
  • visual paths
20
Q

Input from sensory proprioceptors and visual paths provide feedback to primary motor cortex so it can…

A

modify its output

21
Q

Direct input from sensory proprioceptors and visual paths come from…

A

1a afferents of muscle spindle (stretch reflex)

22
Q

Indirect input from sensory proprioceptors and visual paths come from…

A

interneurons from various areas of brain

23
Q

Primary motor cortex controls…

A

fine voluntary movement

  • simple learned tasks involving distal limbs
  • muscles of speech
24
Q

Primary motor cortex is arranged in…

A

functional columns

25
Q

Each unit of the primary motor cortex is responsible for…

A

motor output to a group of synergistic muscles

26
Q

Primary motor cortex is organized…

A

contralaterally

- right brain controls left and vice versa

27
Q

Motor output fibers from giant pyramidal cells in the primary motor cortex originate from…

A

motor homunculus

28
Q

T/F: output fibers in the primary motor cortex travel on specific pathways in spinal cord

A

T

29
Q

Output fibers in the primary motor cortex synapse in…

A

ventral horn of spinal cord w/ motor neurons

30
Q

Output fibers in the primary motor cortex regulates…

A

contractile force of skeletal muscles (somatic motor activity)

31
Q

Corticospinal tracts are the…

A

most important output from motor cortex

32
Q

Corticospinal tracts control…

A

movement to axial and appendicular skeletal muscles below the head

33
Q

Corticospinal tracts begin as..

A

pyramidal tracts

34
Q

Pyramidal tracts have fibers that originate from…

A
  • primary motor cortex

- premotor and supplemental motor cortices

35
Q

Pyramidal tracts travel from…

A

cortex to brainstem

- doesn’t synapse in brainstem

36
Q

Pyramidal tracts divides into 2 types of tracts:

A
  • lateral corticospinal tract

- ventral corticospinal tract

37
Q

Lateral corticospinal tract makes up what percentage of the fibers in the corticospinal tracts?

A

80%

38
Q

T/F: lateral corticospinal tracts do not cross-over midline at the medulla

A

F, they do cross-over

39
Q

Lateral corticospinal tract descend in the…

A

lateral column of white matter of the spinal cord

40
Q

Lateral corticospinal tract synapse directly w/…

A

alpha motor neurons in ventral horn

41
Q

Lateral corticospinal tract control:

A

fine, skilled movements in distal portion of limbs

42
Q

Ventral corticospinal tract makes up what percentage of the fibers in the corticospinal tracts?

A

20%

43
Q

Ventral corticospinal tracts continue…

A

ipsilaterally in ventral white column of spinal cord

44
Q

Ventral corticospinal tract synapse on…

A

interneurons in the ventral horn at the level of the spinal cord

45
Q

Ventral corticospinal tract connects…

A

bilaterally w/ alpha motor neurons

46
Q

Ventral corticospinal tract controls…

A

postural and gross movements in axial (trunk) and proximal limb muscles

47
Q

Corticobulbar tract relays motor output to muscles of…

A
  • eyes
  • face
  • tongue
  • throat
48
Q

Fibers of the corticobulbar tract travels to the…

A

motor nuclei or cranial nerves

49
Q

Subcortical components involved in motor control:

A
  • cerebellum

- basal ganglia

50
Q

Basic structure of cerebellum:

A

2 hemispheres each divided into three lobes

51
Q

Three lobes of the cerebellum:

A
  • flocculonodular
  • anterior lobe
  • posterior lobe
52
Q

Each lobe of the cerebellum has…

A
  • cerebellar cortex

- deep cerebellar nuclei

53
Q

Vestibulocerebellum controls…

A

posture and equilibrium

54
Q

Input for vestibulocerebellum comes from…

A

vestibular apparatus in the inner ear to the flocculonodular lobe

55
Q

Vestibulocerebellum aids w/…

A

equilibrium control, especially w/ respect to head position

56
Q

Vestibulocerebellum is important during performance of…

A

rapid motions involving changes in direction

57
Q

Corticocerebellum (lateral portions of anterior and posterior lobes) control…

A

movement planning

58
Q

Corticocerebellum (lateral portions of anterior and posterior lobes) receives information from…

A
  • supplemental
  • premotor
  • parietal
59
Q

Corticocerebellum (lateral portions of anterior and posterior lobes) involved in…

A
  • planning and initiation of movement to distal parts of limbs
  • motor learning
60
Q

Corticocerebellum (lateral portions of anterior and posterior lobes) outputs through…

A

thalamus to motor and premotor cortices

61
Q

Spinocerebellum (medial portions of anterior and posterior lobes) helps w/…

A

smoothing of limb movement

62
Q

Spinocerebellum (medial portions of anterior and posterior lobes) gets input from…

A

spinal cord pertaining to on-going movement

63
Q

Spinocerebellum (medial portions of anterior and posterior lobes) receives discrete….

A

moment-by-moment information such as limb position and muscle actions (muscle length and tension)

64
Q

Spinocerebellum (medial portions of anterior and posterior lobes) output helps regulate..

A

trunk and proximal limb movement

- corrects errors in output

65
Q

Spinocerebellum (medial portions of anterior and posterior lobes) outputs to what location?

A
  • thalamus

- ventral horn of spinal cord via red nucleus

66
Q

What happens when cerebellum functions improperly?

A

abnormalities of movement occur

67
Q

What are some abnormalities of movement due to improper functioning of cerebellum?

A
  • disorders of coordination (ataxia), equilibrium, and muscle tone
  • errors in direction (dysmetria) and force of movement
  • jerky step-like movements
68
Q

Basal ganglia:

A

numerous nuclei located deep in cerebral hemispheres in close proximity to thalamus

69
Q

Connections and operation of basal ganglia are…

A

very complex

70
Q

Basal ganglia are associated w/…

A

multiple excitatory and inhibitory neurotransmitters

71
Q

Basal ganglia involved in…

A
  • programming and planning movement

- converting abstract thought into voluntary actions

72
Q

Functions of basal ganglia:

A
  • help select movement to be made
  • determine how rapidly movement is to be performed
  • determine how large movement will be (changes intensity of movements)
73
Q

Basal ganglia has two circuits:

A
  • putamen circuit

- caudate circuit

74
Q

Putamen circuit is for…

A

subconscious execution of learned patterns of movement

75
Q

Caudate circuit is for…

A

cognitive planning of sequential and parallel motor patterns to achieve specific goals

76
Q

Two examples of disorders of the motor system:

A
  • parkinson’s

- huntington’s

77
Q

Parkinson’s occurs due to…

A

widespread destruction of dopaminergic neurons in the substantia nigra of the basal ganglia

78
Q

Dopamine produces inhibition of activity in…

A

motor areas of cerebral cortex

79
Q

Symptoms of Parkinson’s:

A
  • muscular rigidity
  • resting tremors
  • bradykinesia
80
Q

Treatments of Parkinson’s:

A
  • L-dopa
  • L-deprenyl: inhibits MOA
  • transplanted fetal dopamine cells
  • destruction of feedback circuitry
81
Q

Huntington’s is a….

A

genetic disease w/ progressive loss of GABA and cholinergic neurons in certain basal ganglia

82
Q

Huntington’s results in…

A

absence of inhibition and excessive excitation of cortex

83
Q

Symptoms of Huntington’s:

A
  • depression
  • dementia
  • loss of motor control
  • chorea (rapid flicking movement of face muscles and distal limbs)
84
Q

T/F: there is a cure for Huntington’s

A

F, only can provide some relief

85
Q

Ways to provide relief for Huntington’s:

A
  • dopamine blockers

- memory aids