Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Neuroscience II > Motor Tracts > Flashcards

Motor Tracts Flashcards

1
Q

What areas of the brain are dedicated to motor planning and coordination?

A

basal ganglia
cerebellum
motor association areas

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Descending pathways include:

A

corticospinal
corticobulbar
bulbospinal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is an example of a local neuronal network?

A

central pattern generator

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Area 4 is known as

A

primary motor cortex (MI)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Area 6 is known as

A

motor association areas

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Premotor cortex (PMC) is located:

A

rostral to primary motor on lateral hemisphere

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Supplemental Motor Cortex (SMA or MII) is located:

A

rostral to primary motor on medial hemisphere

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Somatotopic organization of ventral horn means trunk/axial musculature is located:

A

most medially

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Somatotopic organization of ventral horn means hip/shoulder girdle musculature is located:

A

intermediate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Somatotopic organization of ventral horn means distal limb musculature is located:

A

most laterally
flexors = dorsal
extensors = ventral

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Lateral motor system is more associated with

A

distal limb

fine motor control

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Medial motor system is more associated with

A

girdle and trunk

gross motor control (i.e.: walking and postural adjustment)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

The lateral motor system involves these 2 tracts:

A
  1. lateral corticospinal

2. rubrospinal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

The medial motor system involves these 4 tracts:

A
  1. anterior corticospinal tract
  2. medial and lateral vestibulospinal tracts
  3. medial and lateral reticulospinal tracts
  4. tectospinal tract
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

A unique feature of lateral corticospinal tract is

A

fractionation of limb movements

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

The lateral corticospinal tract is also known as

A

pyramidal tract

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Describe lateral corticospinal tract origin

A

50% from primary motor (area 4)

50% from supplementary (area 6), premotor, somatosensory (area 1,2,3) and other areas of parietal cortex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

How many axons in lateral cortico-spinal tract?

A

approx 1 mil

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

The majority of axons in lateral cortico-spinal tract are ____ myelinated.

A

finely myelinated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Approx ____% of fibers in lateral cortico-spinal tract cross in the ______.

A

90%

caudal medulla

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Most axons of lateral cortico-spinal tract synapse with LMNs @ what location?

A

contralateral spinal cord

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

The fibers of the lateral cortico-spinal tract course from the ______ and then to the posterior limb of the _____.

A

corona radiata

internal capsule

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

The fibers of the lateral cortico-spinal tract course through the ____ in the midbrain.

A

crus cerebri

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

The fibers of the lateral cortico-spinal tract course through smaller fascicles in the ____.

A

basilar pons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

The fibers of the lateral cortico-spinal tract course through the ____ as the pyramids.

A

medulla

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

The fibers of the lateral cortico-spinal tract terminate in the ____.

A

lateral ventral horn

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Describe the functions of the lateral cortico-spinal tract (4)

A
  1. fine motor control of distal musculature
  2. facilitates motor neuron pools of all muscles
  3. deliberate, isolated, fractionated movements
  4. innervates hands and feet
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

______ tract is the only tract that innervates the hands and feet.

A

lateral cortico-spinal tract

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

The _____ tract is the red nucleus in the midbrain that decussates.

A

rubrospinal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

The rubrospinal tract terminates on?

A

contralateral lateral anterior horn in HAND regions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

The rubrospinal tract innervates ____.

A

UE flexors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

The anterior corticospinal tract is composed of approx ___% of the corticospinal fibers.

A

8%

33
Q

The anterior corticospinal tract fibers descend _____.

A

ipsilaterally

34
Q

Where do the anterior corticospinal tract fibers cross?

A

at the level of the cord where they terminate

35
Q

Where do the anterior corticospinal tract fibers terminate?

A

contralateral innervation of medial aspect of ventral horn (with some bilateral innervation)

36
Q

What is the fxn of the anterior corticospinal tract?

A

axial and girdle muscular control

37
Q

Which tracts provide major influence over extensors of trunk and girdle?

A

medial and lateral vestibulospinal tracts

38
Q

The medial and lateral vestibulospinal tracts innervate:

A

ipsilateral limb for equilibrium response

39
Q

The fxn of the medial vestibulospinal tract is:

A

head/eye coordination, head orientation

bilateral innervation

40
Q

The fxn of the lateral vestibulospinal tract is:

A

equilibrium response and extensor activation during stance phase of walking (primarily ipsilateral innervation)

41
Q

The medial vestibulospinal tract only goes to the ____ cord.

A

cervical

42
Q

The medial reticulospinal tract is from the ____.

A

pons

43
Q

The lateral reticulospinal tract is from the ____.

A

medulla

44
Q

The reticulospinal tracts descend in the:

A

ventral and lateral funiculi of the SC

45
Q

The reticulospinal tracts descend _____.

A

bilaterally

46
Q

The reticulospinal tracts terminate in the:

A

medial portion of the anterior horns

47
Q

The medial reticulospinal tract induces excitation of ___ and inhibition of ___.

A

+ extensors

- flexors

48
Q

The lateral reticulospinal tract induces excitation of ___ and inhibition of ___.

A

+ flexors

- extensors

49
Q

The reticulospinal tracts are important in

A

reciprocal movements required for walking, postural control responses

50
Q

The tectospinal tract runs through the:

A

superior colliculus in the midbrain

then decussates

51
Q

The tectospinal tract innervates contralateral _____.

A

neck extensors and eye muscles

52
Q

The tectospinal tract is involved in orientation of

A

head and eyes

turning them to contralateral visual stimuli

53
Q

What are the 2 functions of the corticobulbar tracts?

A
  1. voluntary control over brainstem area

2. adaptation of automatic responses as a result of experience/learning

54
Q

Where do corticobulbar tracts terminate in the brainstem?

A
  1. cranial nerve nuclei
  2. motor areas of the brainstem (vestibular, reticulospinal, tectospinal tracts)
  3. sensory relay nuclei
  4. reticular formation
55
Q

The ________ tracts are the cortical innervations of the brainstem.

A

corticobulbar

56
Q

Corticobulbar fibers descend in the ______ just anterior to corticospinal fibers.

A

internal capsule

57
Q

Corticobulbar fibers go through crus cerebra and exit at the:

A

level of brainstem where they do their innervating

58
Q

Bulbar signs (AKA cortical stroke) include difficulty with ….

A

feeding, swallowing, dysphagia

59
Q

With MCA stroke, recovery of _______ > recovery of _____.

A

trunk/girdle > hand/foot

bilateral innervation versus unilateral innervation

60
Q

There is predominantly contralateral innervation by cortex even though the ______ system has significant bilateral innervation.

A

lateral

61
Q

What is the role of the primary motor cortex?

A

(area 4)

  1. deliberate, fractionated, isolated movement of individual joints in specific directions
  2. facilitate all motor neuron pools
62
Q

What is the role of the supplemental motor cortex?

A
  1. generates pattern of movement involving multiple segments, trunk
  2. internally generated mvments
  3. active in mental rehearsal of moment
  4. assemble motor programs or routines
  5. ipsilateral innervation
63
Q

What is the role of the premotor cortex?

A
  1. generates movemnt pattern in response to external stimuli
  2. includes inputs also to hand and distal limb motor neurons
  3. involved in reaching and grasping with visual guidance
64
Q

Premotor cortex receives input from posterior parietal cortex via the dorsal visual stream for what fxn?

A

reaching and grasping with visual guidance

65
Q

LMN always refers to:

A

alpha MN in SC

66
Q

UMN refers to:

A

neurons in other parts of CNS that drive the LMN

67
Q

UMN lesion usually results in ______.

A

spasticity

68
Q

LMN lesion always results in ______.

A

hyporeflexia

69
Q

Babinski sign (plantar response) indicates:

A

corticospinal lesion

70
Q

What is a normal (-) response to babinski test?

A

toe flexion

71
Q

What is an abnormal (+) response to babinski test?

A

any amount of extension

72
Q

A “bulbar sign” is any clinical sign related to:

A

brainstem fxn (particularly cranial nerves)

73
Q

MCA cortical stroke often results in:

A

contralateral hemiparesis (aka hemiplegia/hemianesthesia)

74
Q

MCA stroke characteristics:

A

less contralateral activation
distal muscles most affected, trunk least affected
gross movement patterns (synergies)
loss of fractionated mvmnt
initially present with bulbar signs which usually resolve

75
Q

UE is usually ____ dominant and LE is usually _____ dominant with MCA synergies.

A

UE: flexion
LE: extension

76
Q

Decorticate posturing:

A 
remove cortex (rubrospinal tract intact)
extension of LE and flexion of UE
77
Q

Decerebrate posturing:

A

midollicular (below red nucleus)
extension of UE and LE
IR and plantar flexion

78
Q

Explain why UE and LE have similar posturing with decerebrate rigidity:

A

extension throughout due to dominant influence of vestibular system

Neuroscience II (13 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions