Brainscape's Knowledge GenomeTM

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


See full index

DPT 803: Neurobio 2 > Lecture 5- Motor control- LMN > Flashcards

Lecture 5- Motor control- LMN Flashcards

1
Q

where does the corticospinal tract end within the spinal cord

A

mainly in the vental horn and slightly intermediate zone

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

where does the rubrospinal tract end within the spinal cord

A

intermediate zone

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

where does the reticulospinal tract end within the spinal cord

A

ventral horn

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

what are the patterns and functions of med vestibulospinal tract in LMN

A

end in neck/thoracic]
B neck extensors

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

what are the patterns and functions of med corticospinal tract in LMN

A

all spinal levels
B postural flexor m control

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

what are the patterns and functions of pontine reticulospinal tract in LMN

A

all spinal levels
B prox extremity ext

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

what are the patterns and functions of lat vestibulospinal tract in LMN

A

all spinal levels
ipsi prox extremity ext

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

what are the patterns and functions of medullary reticulospinal tract in LMN

A

all spinal levels
b distal extremity flx

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

what are the patterns and functions of rubrospinal tract in LMN

A

end in neck/thoracic
distal UE flexors

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

what are the patterns and functions of lat corticospinal tract in LMN

A

all spinal levels
distal extremity flexor
fine motor control

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

what is a type I muscle fiber

A

slow twitch
high concentration of mitochondria
less glycogen

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

what is a type IIa muscle fiber

A

fast twitch
fatigue resistant
medium concentration of mitochondria and glycogen

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

what is type IIb muscle fiber

A

fast twitch
fatiguable
low concentration of mitochondria
more glycogen

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

can muscle fibers transition from one type to another

A

yes, type II can change to type I

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

True/False
All muscles contain all 3 types of muscle fibers with the same ratio

A

false
all 3 muscle fibers aer present, but they have different ratios

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

what happens with a denervated muscle

A

all LMNs are lost

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

what happens when the LMN is loss

A

polio

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

what type of LMN pairs with type I muscle fibers

A

small LMN
less powerful , last hours
fine motor and postural control

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

what type of LMN pairs with type IIa muscle fibers

A

medium LMN
more powerful, last 1 hour
mixture between I and IIb, gross motor

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

what type of LMN pairs with type IIb muscle fibers

A

large LMN
most powerful, last 1 minute
gross motor and power

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

how does motor unit size vary between gross motor and fine motor functions

A

gross- 1 LMN innervates several hundred/thousand m fibers, large motor unit

Fine= 1 LMN several M fibers, small motor unit

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

how are extra-ocular eye muscle considered type 1

A

they are constantly working aka non- fatiguable

however, can move fast d/t the ratio of LMN per motor unit

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

True/False:
There is a 1:1 ratio of LMN to motor unit except with facial expression m

A

true
they have several LMNs overlap different facial m

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

what is intensity encoded by to create LMN activation and force production

A

AP frequency

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

what membrane AP is along the LMN axon terminal

A

presynaptic

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

what membrane AP is along the m fibers

A

postsynaptic

27
Q

what happens when AP is over 80 Hz

A

tetanus

28
Q

what is the difference between temporal and spatial summation

A

temporal= one presynaptic neuron rapid firing to one postsynaptic

spatial= multiple presynaptic firing to one postsynaptic

29
Q

why are type 1 m fibers activated first

A

due to small LMN which are higher resistance and need higher voltage

30
Q

if more force is needed, what muscle fibers are recruited and what regulates these m fibers

A

type II
GTO

31
Q

what is active insufficiency

A

the m is so shortened that it decreases m force production

32
Q

what is passive insufficiency

A

m is so elongated that it decreases force production

33
Q

what is the function of nuclear bag cells within the m spindle

A

static- length (stretch)
dynamic- velocity (DTR)

34
Q

what is the function of nuclear chain cells within the m spindle

A

only static for length

35
Q

what doe the alpha motor neurons innervate within the muscle

A

LMN extrafusal m cells
free nerve endings

36
Q

what doe the gamma motor neurons innervate within the muscle

A

LMN intrafusal m cells

37
Q

what doe the primary motor neurons innervate within the muscle

A

Ia
nuclear bag and chain cells
both static and dynamic

38
Q

what doe the secondary motor neurons innervate within the muscle

A

II
static nuclear bag and chain cells

39
Q

if we have an extrafusal m concentric contraction, what is detected and adjusted

A

decrease dynamic = decrease Ia activity

40
Q

if we have an extrafusal m isometric contraction, what is detected and adjusted

A

increase Ia/II static nuclear bag and chain

41
Q

if we have an extrafusal m eccentric contraction, what is detected and adjusted

A

increase in Ia dynamic nuclear bag

42
Q

what is the function of the m spindle

A

position sense (static)= Ia/II
kinesthesia (dynamic)= Ia

43
Q

within the cortiobulbar tract, what CN do not have bilateral distribution

A

CN V/XII normally have contralateral bias

44
Q

within the cortiobulbar tract, what CN innervates all head m spindle of Ia and II

A

CN V

45
Q

a patient shows weakness of inf facial muscles, where is the lesion

A

UMN lesion

46
Q

a patient has a UMN lesion resulting in decreased function of bilateral scalp, where is the lesion and what hierarchal level

A

cingulate motor cortex
level 4
dorsal motor nucleus CN VII

47
Q

a patient has a UMN lesion resulting in decreased function contralateral face, where is the lesion and what hierarchal level

A

motor cortex and post parietal cortex
level IV and III
ventral motor nucleus

48
Q

a patient has a UMN lesion resulting in decreased function of face and scalp, where is the lesion and what hierarchal level

A

deep brain structure
level II

49
Q

a patient presents with decreased function of the ipsilateral face and scalp, where is the lesion

A

LMN

50
Q

what CN are responsible for proprioception of facial m

A

inter CN V and VII anastomosis

51
Q

what is the function of the intra CN VII anastomosis

A

innervate different motor units

52
Q

what does not happen with a regional injury to intra CN VII anastomosis

A

does not affect facial expression

53
Q

what is the importance of the spinal/brainstem reflex

A

closed loop
sensory goes in
basic motor function
differential diagnosis

54
Q

what are the two types of spinal/brainstem reflexes

A

intrasegmental- at same level
intersegmental- multiple levels

55
Q

what are the components of the spinal/brainstem reflex

A

receptor detects stimuli which is afferent and is sent by interneurons (maybe) to spinal cord for integration then efferent signals are sent to effectors for action

56
Q

what is the flexor reflex components

A

noxious stimuli is sent through nociceptice axons (Ad) within intersegmental reflex in spinal cord (Lissauers tract) and efferent signals excite flexors and inhibit extensors to remove injured body part away from noxious stimuli

57
Q

where is flexor reflex most common

A

more common in UE but if in LE crossed extension reflex is also there

58
Q

what is the crossed extension reflex

A

noxious stimuli is sent through nociceptive axons. interneurons have alternating excitatory and inhibitory signals. which excite ipsi flexors and contra extensors while inhibiting ipsi ext and contra flx. Thus the affected limb withdrawals and contra is there to maintain balance

59
Q

what is the DTR signals sent for patellar tendon reflex

A

afferent dynamic (Ia) signals of quad sent to spinal cord for alpha motor neurons to excite quads through intrasegmental and inhibit HS through interneuron intersegmental reflex. resulting in knee jerk reaction

60
Q

what is the importance of GTO reflex

A

fine adjustments of force production
initiate additional forms of autogenic inhibition at higher tension levels- clasp knife effects

61
Q

how can reflexes be modulated by UMN

A

Ia signals to spinal cord then moves through various segments (spinal reflex) then to higher levels (either conscious or unconscious) which then can override

why we have to distract pt during DTR

62
Q

if spinal/brainstem reflex are considered closed loop, what is the difference between CPG open loop

A

spinal reflex needs sensory input aka closed loop

CPG does not. It is a pre written motor program that does not need sensory info

63
Q

what are the voluntary locomotor regions

A

cont of reticular formation system
diencephalic and mesencephalic

64
Q

what is the function of DLR and MLR and what regulates these regions

A

to coordinate CPG that are regulated through the hierarchical control systems

DPT 803: Neurobio 2 (9 decks)

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