Brain Controlled Motor Output Flashcards
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
Each unit of the primary motor cortex is responsible for...
motor output to a group of synergistic muscles
26
Primary motor cortex is organized...
contralaterally
| - right brain controls left and vice versa
27
Motor output fibers from giant pyramidal cells in the primary motor cortex originate from...
motor homunculus
28
T/F: output fibers in the primary motor cortex travel on specific pathways in spinal cord
T
29
Output fibers in the primary motor cortex synapse in...
ventral horn of spinal cord w/ motor neurons
30
Output fibers in the primary motor cortex regulates...
contractile force of skeletal muscles (somatic motor activity)
31
Corticospinal tracts are the...
most important output from motor cortex
32
Corticospinal tracts control...
movement to axial and appendicular skeletal muscles below the head
33
Corticospinal tracts begin as..
pyramidal tracts
34
Pyramidal tracts have fibers that originate from...
- primary motor cortex
| - premotor and supplemental motor cortices
35
Pyramidal tracts travel from...
cortex to brainstem
| - doesn't synapse in brainstem
36
Pyramidal tracts divides into 2 types of tracts:
- lateral corticospinal tract
| - ventral corticospinal tract
37
Lateral corticospinal tract makes up what percentage of the fibers in the corticospinal tracts?
80%
38
T/F: lateral corticospinal tracts do not cross-over midline at the medulla
F, they do cross-over
39
Lateral corticospinal tract descend in the...
lateral column of white matter of the spinal cord
40
Lateral corticospinal tract synapse directly w/...
alpha motor neurons in ventral horn
41
Lateral corticospinal tract control:
fine, skilled movements in distal portion of limbs
42
Ventral corticospinal tract makes up what percentage of the fibers in the corticospinal tracts?
20%
43
Ventral corticospinal tracts continue...
ipsilaterally in ventral white column of spinal cord
44
Ventral corticospinal tract synapse on...
interneurons in the ventral horn at the level of the spinal cord
45
Ventral corticospinal tract connects...
bilaterally w/ alpha motor neurons
46
Ventral corticospinal tract controls...
postural and gross movements in axial (trunk) and proximal limb muscles
47
Corticobulbar tract relays motor output to muscles of...
- eyes
- face
- tongue
- throat
48
Fibers of the corticobulbar tract travels to the...
motor nuclei or cranial nerves
49
Subcortical components involved in motor control:
- cerebellum
| - basal ganglia
50
Basic structure of cerebellum:
2 hemispheres each divided into three lobes
51
Three lobes of the cerebellum:
- flocculonodular
- anterior lobe
- posterior lobe
52
Each lobe of the cerebellum has...
- cerebellar cortex
| - deep cerebellar nuclei
53
Vestibulocerebellum controls...
posture and equilibrium
54
Input for vestibulocerebellum comes from...
vestibular apparatus in the inner ear to the flocculonodular lobe
55
Vestibulocerebellum aids w/...
equilibrium control, especially w/ respect to head position
56
Vestibulocerebellum is important during performance of...
rapid motions involving changes in direction
57
Corticocerebellum (lateral portions of anterior and posterior lobes) control...
movement planning
58
Corticocerebellum (lateral portions of anterior and posterior lobes) receives information from...
- supplemental
- premotor
- parietal
59
Corticocerebellum (lateral portions of anterior and posterior lobes) involved in...
- planning and initiation of movement to distal parts of limbs
- motor learning
60
Corticocerebellum (lateral portions of anterior and posterior lobes) outputs through...
thalamus to motor and premotor cortices
61
Spinocerebellum (medial portions of anterior and posterior lobes) helps w/...
smoothing of limb movement
62
Spinocerebellum (medial portions of anterior and posterior lobes) gets input from...
spinal cord pertaining to on-going movement
63
Spinocerebellum (medial portions of anterior and posterior lobes) receives discrete....
moment-by-moment information such as limb position and muscle actions (muscle length and tension)
64
Spinocerebellum (medial portions of anterior and posterior lobes) output helps regulate..
trunk and proximal limb movement
| - corrects errors in output
65
Spinocerebellum (medial portions of anterior and posterior lobes) outputs to what location?
- thalamus
| - ventral horn of spinal cord via red nucleus
66
What happens when cerebellum functions improperly?
abnormalities of movement occur
67
What are some abnormalities of movement due to improper functioning of cerebellum?
- disorders of coordination (ataxia), equilibrium, and muscle tone
- errors in direction (dysmetria) and force of movement
- jerky step-like movements
68
Basal ganglia:
numerous nuclei located deep in cerebral hemispheres in close proximity to thalamus
69
Connections and operation of basal ganglia are...
very complex
70
Basal ganglia are associated w/...
multiple excitatory and inhibitory neurotransmitters
71
Basal ganglia involved in...
- programming and planning movement
| - converting abstract thought into voluntary actions
72
Functions of basal ganglia:
- 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
Basal ganglia has two circuits:
- putamen circuit
| - caudate circuit
74
Putamen circuit is for...
subconscious execution of learned patterns of movement
75
Caudate circuit is for...
cognitive planning of sequential and parallel motor patterns to achieve specific goals
76
Two examples of disorders of the motor system:
- parkinson's
| - huntington's
77
Parkinson's occurs due to...
widespread destruction of dopaminergic neurons in the substantia nigra of the basal ganglia
78
Dopamine produces inhibition of activity in...
motor areas of cerebral cortex
79
Symptoms of Parkinson's:
- muscular rigidity
- resting tremors
- bradykinesia
80
Treatments of Parkinson's:
- L-dopa
- L-deprenyl: inhibits MOA
- transplanted fetal dopamine cells
- destruction of feedback circuitry
81
Huntington's is a....
genetic disease w/ progressive loss of GABA and cholinergic neurons in certain basal ganglia
82
Huntington's results in...
absence of inhibition and excessive excitation of cortex
83
Symptoms of Huntington's:
- depression
- dementia
- loss of motor control
- chorea (rapid flicking movement of face muscles and distal limbs)
84
T/F: there is a cure for Huntington's
F, only can provide some relief
85
Ways to provide relief for Huntington's:
- dopamine blockers
| - memory aids
