Neuro Block 3 Fowler Lectures

Front 1

what structure does this:
planning
initiating
directing voluntary movements

Back 1

motor cortex

Front 2

what structure:
basic movements and postural control

Back 2

brainstem

Front 3

what structure:
gating proper initiation of movement

Back 3

basal ganglia

Front 4

what structure:
sensory motor coordination

Back 4

cerebellum

Front 5

what structure:
reflex coordination

Back 5

local circuit neurons

Front 6

what are other names for the muscle stretch reflex?

Back 6

deep tendon reflex
myotatic reflex arc
muscle jerk reflex

Front 7

the reflex circuit is normally responsible for the steady level of tension in muscles called

Back 7

muscle tone

Front 8

hammer tap stretches tendon which in turn stretches what in the leg extensor muscle?

Back 8

sensory receptors

Front 9

sensory neurons synapse with and excite motor neuron in the spinal cord.
sensory neuron also excite pinal interneuron which synapses to inhibit what?

Back 9

motor neuron to the flexor muscles

Front 10

motoe neurons conducts AP to synapse on extensor muscle fibers causing

Back 10

contraction

Front 11

inteneuron inhibits motor neuron in flexor muscle causing

Back 11

flexor muscle relaxation

Front 12

what is reciprocal innervation?

Back 12

increases Ia inhibitory interneuron activity --> decrease in alpha motor neuron stimulation to antagonist or heteronymous muscle

Front 13

Sherrington's law of reciprocal innervation states:

Back 13

when contraction of a muscle is stimulated, there is a simultaneous inhibition of its antagonist

Front 14

muscle spindles comprise of ______arranged in parallel with ______that make up the bulk of the muscle

Back 14

8-10 intrafusal fibers
extrafusal fibers

Front 15

large diameter sensory fibers are called

Back 15

Ia afferents
have largest axons in peripheal nerves
allow rapid adjustments of reflex arc when muscle istretched

Front 16

Ia afferents are coiled around

Back 16

central part of muscle spindle

Front 17

stretch imposed on muscle deforms intrafusal muscle fibers which initiates:

Back 17

AP by activating mechanically gated ion channels in the afferent axons coiled around spindle

Front 18

centrally projecting branch of sensory neuron forms monosynaptic excitatory connections with: (2 things)

Back 18

1. alpha motor neurons in ventral horn of spinal cord that innervate same (homonymous) muscle
2. inhibitory connections with alpha motor neurons of antagonist (heteronymous) muscles via local circuit neurons

Front 19

transient involuntary contraction of a group of muscles/individual muscle of muscle fibers

Back 19

muscle spasms

Front 20

forceful, sustained spasm usually lasting for seconds to minutes

Back 20

muscle cramp

Front 21

people with fasciculations (lower motor neuron syndrome) tend to get:

Back 21

cramps

Front 22

actively stretching cramping muscle by voluntary contraction of antagonist can relieve cramping by

Back 22

stretching out the antagonist sends an inhibitory signals to cramped muscle

Front 23

all fibers of A MOTOR UNIT contract is called

Back 23

twitch

Front 24

electrolyte imbalance can cause a nonspecific increase in neuronal and muscle fiber excitability

Back 24

dehydration

Front 25

low blood levels of either calcium or magnesium directly increase the excitability of both:

Back 25

nerve endings and muscles they stimulate

Front 26

what will cause decrease availability of ca and/or mg in body fluids?

Back 26

diuretics
hyperventilation
excessive vomiting
inadequate calcium and/or magnesium in diet
inadequate calcium absorption due to vitamin D deficiency
poor function of parathyroid gland - tiny gland in neck that regulates calcium balance

Front 27

low levels of what will causes muscle cramps?

Back 27

low potassium
it is more common for low potassium to be associated with muscle weakness

Front 28

stretch reflex can be modeled as a

Back 28

negative feedback system with muscle length as controlled variable

Front 29

what are the steps to stretch reflex?

Back 29

Muscle length is increased (e.g., tapping of tendon with reflex hammer)  stretches muscle spindle  increases spindle afferent discharge  increases excitation of a-motor neuron  muscle length is decreased

Front 30

what is an involuntary muscle contraction in response to muscle stretch?

Back 30

stretch reflex

Front 31

stretch reflex involves ______activation of alpha motor neuron to homonymous muscle

Back 31

monosynaptic

Front 32

the proprioceptor of the stretch reflex is the

Back 32

muscle spindle

Front 33

muscle spindles composed of sensory receptors called

Back 33

intrafusal fibers

Front 34

lie parallel to much larger muscle fibers

Back 34

extrafusal fibers

Front 35

respond to muscle length and to velocity of muscle stretch

Back 35

muscle spindles

Front 36

dynamic nuclear bag1 fibers

Back 36

dynamic intrafusal fiber

Front 37

static nuclear bag2 and chain fibers

Back 37

static intrafusal fibers

Front 38

the typical muscle spindle contains 2 types of intrafusal muscle fibers:

Back 38

1. nuclear bag fibers
2. nuclear chain fibers

Front 39

nuclear bag fibers are _____ and _____ than the nuclear chain fibers

Back 39

1. thicker
2. longer

Front 40

nuclear is an accumulation of

Back 40

their nuclei in expanded bag-like equatorial region

Front 41

do nuclear chain fiber have an equatorial bulge?

Back 41

no
their nuclei are lind up in equatorial region

Front 42

nuclear bag fibers are innervated by

Back 42

Type Ia afferent axons

Front 43

nuclear chain fibers are innervated by

Back 43

Type II afferent axons

Front 44

differentiation btwn dynamic and static components of sensory stretch response may arise from __________ properties of intrafusal fibers

Back 44

different viscoelastic

Front 45

jelly-fileld sack, bag fiber, stretching muscle stretch sack, viscous flow within sac

Back 45

dynamic intrafusal fibers

Front 46

static and intrafusal fibers and group II afferents respond to the level of:

Back 46

sustained stretch or muscle length

Front 47

dynamic intrafusal fiber and Ia afferent carry sensory component of the

Back 47

clinical stretch reflex

Front 48

what neurons innervate contractile elements at the poles of muscle spindles

Back 48

gamma motor neurons

Front 49

activation of contractile elements causes the central region of muscle spindle to stretch like a rubber band which in turn stretched

Back 49

sensory endings --> increases sensitivity to stretch associated with muscle lengthening

Front 50

dynamic gamma efferent project to

Back 50

bag1 fibers

Front 51

static gamma afferents project to

Back 51

bag 2 and chain fibers

Front 52

gamma motor neuron activation increases what of the stretch reflex?

Back 52

GAIN

Front 53

_____is enhanced when physical demand for performance is needed

Back 53

GAIN

Front 54

decreased inhibitory mechanisms, hyperexcitability of alpha motor neurons, peiripheral nerve sprouting after transection, and/or
increased gamma fiber activity can lead to

Back 54

hyperreflexia

Front 55

the CNS uses what to modulate the stretch reflex?

Back 55

gamma motor neurons

Front 56

gamma motor neurons contribute to the gain of stretch reflex by modulating:

Back 56

the sensitivity of the spindle to stretch

Front 57

inceased central drive to gamma neuron leads to increase in

Back 57

gain of stretch reflex

the slope of velocity/length of spindle vs. spindle afferent discharge increases

Front 58

oartial steady level of muscle contraction at rest that maintains a normal posture

Back 58

muscle tone

Front 59

since muscle are always under some degree of stretch, the gain (or sensitivity) of the stretch reflex circuit contributes to

Back 59

steady state level of muscle tone

Front 60

spasticity

Back 60

symptoms of hypertonia and hyperreflexia

Front 61

in upper motor neuron syndome, the gain (or sensitivity) of the stretch reflex is increased or decreased?
this contributes to what?

Back 61

increased
spasticity

Front 62

clonus

Back 62

series of involuntary muscular contractions due to sudden stretching of muscle

Front 63

clonus is associated with what kinds of lesions?
what can these lesions be caused by?

Back 63

upper motor neuron lesions caused by:
stroke
MS
spinal cord damage
hepatic encephalopathy

Front 64

small spontaneous twitching is called

Back 64

fasciculations

Front 65

clonus most commonly occurs in the

Back 65

ankles

Front 66

sustained clonus of how many beats is considered abnormal

Back 66

5 beats or MORE

Front 67

dorsal rhizotomy

Back 67

severing of dorsal spinal nerve root to relieve gamma-spasticity

Front 68

why would gamma-spasticity occur?

Back 68

remove inhibition from gamma motor neurons
caused by increased central drive to motor neurons

Front 69

gamma spasticity is eliminated by

Back 69

dorsal root section
increase central drive upon gamma motor neurons, not alpha motor neurons

Front 70

is alpha spasticity affected by dorsal root section?

Back 70

no

Front 71

is there change in spindle activity in UMN syndrome?

Back 71

no, the central excitatory state of cord appears to be high

Front 72

what neurons innervate intrafusal fibers?

Back 72

gamma motor neurons

Front 73

coactivation of alpha and gamma motor neurons prevents

Back 73

unloading of muscle spindle
allows spindles to function at all muscle lengths during movements and postural adjustments

Front 74

preactivation of alpha and gamma motor neurons by descending motor projections increases

Back 74

muscles stiffness
improves joint control

Front 75

Do group Ia afferent fibers influence gamma motoneurons?

Back 75

no

Front 76

alpha motor neuron activation with gamma

Back 76

fills in Ia response during contraction to prevent unloading

Front 77

preactivation of gamma neurons by decending motor projections does two things

Back 77

increases muscle stiffness
improves joint control

i.e. 50-100 msec preactivation of leg extensors in preparation of hopping
co-contraction of forearm flexors and extensors in preparation for catching a ball

Front 78

modification of what would result in wide ranging alterations in spinal motor control?

Back 78

central drive of gamma motor neurons

Front 79

examples of monosynaptic reflex

Back 79

muscle stretch reflex (MSR)
deep tendon reflex (DTR)

Front 80

reciprocal innervation (or inhibition)
flexion reflex
flexion-crossed extension
clasp-knife (or autogenic inhibition)

Back 80

polysynaptic reflexes

Front 81

withdrawal reflex in response to cutaneous or nociceptive stimulus

Back 81

flexion reflex

Front 82

what reflex is elicited at a higher stimulus threshold?

Back 82

crossed-extension reflex

Front 83

proprioceptor sensitive to muscle tension

Back 83

golgi tendon organ

Front 84

what is the sensory input for the clasp-knife reflex?

Back 84

golgi tendon organ

Front 85

golgi tendon organ transmits impulse via

Back 85

Ib afferent

Front 86

what reflex?
sudden decline in resistance to stretch
autogenic inhibition via Ib inhibitory interneuron

Back 86

clasp-knife reflex

Front 87

_________ limit alpha motor neuron overactivation during reflexes

Back 87

Renshaw cells

Front 88

renshaw cells are excited monosynaptically by

Back 88

motor axon collaterals

Front 89

renshaw interneurons exert a negative feedback inhibition of alpha-motor neurons by

Back 89

recurrent inhibition

(do not confuse with reciprocal innervation)

Front 90

what does C. tetani toxin do?

Back 90

inhibit release of glycine from Renshaw cells resulting in tonically contracted muscles

Front 91

where are Renshaw cells found?

Back 91

in the gray matter of spinal cord and are associatered with alpha motor neurons

Front 92

Renshaw cells utilize what neurotransmitter?

Back 92

glycine

Front 93

what poison bind glycine on motor neuron to prevent activation?

Back 93

strychnine binds glycine receptors on motor neuron preventing their activation
predisposes someone to tetanic contractions
prove fatal is diaphragm becomes involved

Front 94

stretch reflex is monosynaptic or polysynaptic?

Back 94

monosynaptic

Front 95

what reflexes are polysynaptic?

Back 95

flexion
flexion crossed extension
clasp-knife reflex

Front 96

what is the afferent for flexion?

Back 96

group A

Front 97

afferent for flexion crossed extension?

Back 97

group C

Front 98

afferent for clasp-knife reflex?

Back 98

Ia and Ib

Front 99

function of flexion
high or low threshold
subserves...

Back 99

withdrawal from nonpainful stimuli, low threshold
subserves touch

Front 100

function of flexion crossed extension
threshold and subserves...

Back 100

withdrawal from painful stimuli
high threshold
subserves nociception

Front 101

clasp-knife reflex function
subserves
threshold

Back 101

protection from tension
subserves muscle tension
high threshold

Front 102

what syndrome is associated with hyporeflexia and hypotonia

Back 102

LMN

Front 103

what syndrome is associated with hyperreflexia and hypertonia?

Back 103

UMN

Front 104

spasticity is a cardinal sign for what?

Back 104

UMN syndrome

Front 105

spasticity is

Back 105

velocity dependent increase in stretch reflex in absence of volitional activity

Front 106

series of involuntary rapid muscle contractions about 3Hz in response to stretching of a muscle

Back 106

Clonus

Front 107

what ranges from feelings of stiffness/involuntary muscle spasm or jerks to a variety of sensory stimuli (exaggerated withdrawal reflex)

Back 107

spasticity

Front 108

lesion of descending brainstem or cortical motor tracts causes what to occur within minutes to hours

Back 108

(gamma)-spasticity

Front 109

after spinal cord injury, what develops weeks to months after spinal shock?

Back 109

spasticity

Front 110

what occurs after acute spinal cord injury (SCI) ?

Back 110

spinal shock

Front 111

how long can spinal shock last?

Back 111

occurs within seconds, persists for weeks to months

Front 112

what are the symptoms of spinal shock?

Back 112

hypotonia
areflexia

Front 113

during the months after SCI, what happens?

Back 113

spastic syndrome

Front 114

what are the symptoms of spatic syndrome?

Back 114

exaggerated tendon reflexes
increased muscle tone
muscle spasms
change in hypoexcitability (due to acute loss of suprespinal excitatory input resulting in hyperpolarized alpha MN) of alpha motoneurons during spinal shock to hyperexcitability during spasticity

Front 115

hypotonia in spinal shock means

Back 115

flaccid paralysis below lesion
loss of respiration with phrenic involvement

Front 116

areflexia in spinal shock means

Back 116

loss of spinal stretch reflexes
decreased sympathetic outflow resulting hypotension
possible hypotensive shock
absent spincteric reflexes leading to urinary and fecal retention
overfilled bladder

Front 117

what term has these characteristics:
increased alpha motor neuron excitability
denervation hypersenstivity
loss of inhibitory interneurons
reinnervation-induced sprouting of segmental axons

Back 117

spasticity

Front 118

CNS lesions leading to UMN syndrome causes 2 kinds of signs

Back 118

negative signs
positive signs

Front 119

negative signs

Back 119

loss of function
i.e. paresis/paralysis

Front 120

positive signs

Back 120

reorganization of motor system functions
release phenomena:
unhampered activity of lower spinal circuits when a higher inhibiting control is removed
motor automatisms may reflect primitive brainstem and spinal motor patterns released from tonic inhibition normally exerted by forebrain structures
reappearance of infant reflexes

Front 121

what are some positive signs of UMN syndrome?

Back 121

spastic catch
spastic paralysis
clonus
babinski sign
tonic neck reflex

Front 122

spastic catch

Back 122

sudden increase in resistance to passive limb movement

Front 123

spastic paralysis

Back 123

muscle tone and stretch reflexes are abnormally HIGH causing limb to resist movement by an examiner

Front 124

3-7Hz oscillatory motor response to muscle stretch

Back 124

clonus
strong deep tendon reflex that occurs when CNS fails to inhibit it

Front 125

how can you eliminate clonus?

Back 125

dorsal rhizotomy

Front 126

myoclonus

Back 126

irregular and uncontrollable jerks of a muscle or group of muscles

Front 127

Babinski-sign = plantar reflex test for

Back 127

verifies the presence and absence of problems in the corticospinal tract

Front 128

adult response of babinski

Back 128

plantar flexion of big toe and adduction of small toes

Front 129

pathological infant response to babinski

Back 129

dorsiflexion (extension) of the big toe and fanning of the toes

Front 130

what is the fencing reflex, an UMN sign

Back 130

tonic neck reflex

Front 131

what will cause muscle atrophy: LMNS or UMNS

Back 131

LMNS

Front 132

what two pathways original in the motor cortex?

Back 132

lateral corticospinal
ventral corticospinal

Front 133

what is the function of cortical pathways?

Back 133

control of voluntary movements and anticipatory postural changes

Front 134

what are the pathways of the ventromedial brainstem?

Back 134

reticulospinal arise from reticular formation
tectospinal arise from superior colliculus
vestibulospinal arise from vestibular complex

Front 135

what are the pathways of the ventrolateral brainstem?

Back 135

rubrospinal arise from red nucleus

Front 136

what is the function of the ventromedial brainstem pathways?

Back 136

control of posture and balance of head, neck, trunk through projections to proximal and axial musculature

Front 137

what is the function of the dorsolateral brainstem pathways?

Back 137

flexion-biased control of distal upper limb segments

Front 138

ventromedial brainstem use what kind of fibers?
where do they project?

Back 138

Group A fibers
trunk and girdle

Front 139

ventrolateral group use what kind of fibers?
whre do they project?

Back 139

Group B fibers
arms and hand
significant cortical projections

Front 140

where do corticospinal projections terminate?

Back 140

A fibers bilaterally in ventromedial IZ
B fibers terminate contralaterally in dorsolateral IZ directly on motoneurons innervating arm and hand

Front 141

mediolateral rule

Back 141

medial pathways exert principal control over proximal axial musculature whereas lateral pathways exert principal control over distal limb musculature

Front 142

what are the integration centers of the reticulospinal pathway?

Back 142

pontine and medullary RF

Front 143

major sensory input for reticulospinal pathway?

Back 143

proprioceptors

Front 144

primary function of reticulospinal pathway?

Back 144

integration of proprioceptive input to maintain balance and posture

Front 145

what are the integration centers of the tectospinal (colliculospinal) pathway?

Back 145

superior colliculi

Front 146

what is the major sensory inputs for the tectospinal pathway?

Back 146

eyes and ears

Front 147

what is the function of the tectospinal pathway?

Back 147

involuntary orientation of head and eyes to visual and auditory stimuli

Front 148

what is the integration center of the vestibulospinal pathway?

Back 148

vestibular complex

Front 149

what is the major sensory input for vestibulospinal pathway?

Back 149

vestibular system

Front 150

what is the primary function of vestibulospinal pathway?

Back 150

integration of vestibular input to maintain balance and posture

Front 151

what structure is involved in arousal state, autonomic function, pain regulation, postural control?

Back 151

reticular formation

Front 152

what structure?
receives visual inputs in superficial layers
deep layers receives auditory and somatosensory inputs
help orient head and eyes toward something seen and/or heard

Back 152

superior colliculus

Front 153

the major tracts of the vestibular system include

Back 153

vestibulospinal tract -maintains eq
vestibuloocular - controls saccadic eye movements
ascending vestibulocortical tract which causes dizziness when stimulated

Front 154

tectospinal
vestibulospinal
reticulospinal
all terminate where?

Back 154

lamina 7-9

interneurons of lamina 7 (intermediate zone)
lamina 8 (motor interneurons) and on dendrites of motor neurons whose soma reside in lamina 9

Front 155

what are the two br of vestibulospinal pathway?

Back 155

medial and lateral

Front 156

major function of rubrospinal tract in nonhuman primates

Back 156

in primates, red nucleus and rubospinal tract mediate voluntary movement and fine motor control of distal extremities analogous to those of corticospinal tract

Front 157

is there a rubrospinal tract in humans?

Back 157

small and only a few fibers project into spinal cord

Front 158

in humans, what is the major output of red nucleus?

Back 158

inferior olive

Front 159

rubrospinal tract's muscle actions

Back 159

excites proximal arm flexors
inhibits upper proximal arm extensors (flexor bias)

Front 160

tectospinal muscle actions

Back 160

orient movements of head and eyes

Front 161

vestibulospinal -medial
muscle action

Back 161

reflex control of NECK muscles

Front 162

vestibulospinal-lateral
muscle action

Back 162

excites extensors and inhibits flexors
increases muscle tone of axial and proximal muscles
(opposite to rubrospinal)

Front 163

pontine reticulospinal
muscle action

Back 163

same as lateral vestibulospinal
excites extensors and inhibits flexors
increases muscle tone of axial and proximal muscles

Front 164

medullary reticulospinal
muscle action

Back 164

opposite of pontine reticulospinal
inhibits extensors, excites flexors
decreases muscle tone of axial and proximal muscle

Front 165

descending cortical tracts impose what on the action of motor brainstem tracts on muscle groups?

Back 165

inhibitory tone

Front 166

lesion of descending cortical tracts can lead to:

Back 166

positive signs
where actions on muscle groups of brainstem motor tracts are relatively unopposed by cortical modulation (disinhibition)

Front 167

what are signs of disinhibition?

Back 167

posturing and spasticity

Front 168

spasticity can occur after what two types of injury?

Back 168

spinal cord injury
brainstem injury

Front 169

involuntary flexion and extension of arms and legs usually indicating severe brainstem injury

Back 169

abnormal posturing

Front 170

________exert latent modulation of reflexes and of flexor/extensor muscle tone that is normally suppressed

Back 170

brainstem motor centers

Front 171

when descending cortical modulation is interrupted, what occurs?

Back 171

posturing

Front 172

________ consists of adduction of upper arms, flexion of lower arms, wrists and fingers, lower extremities extend

Back 172

decorticate posturing

Front 173

________consists of adduction of upper arms, extension and pronation of lower arms, along with extension of lower extremities

Back 173

decerebrate posturing

Front 174

legs stiffen and arms rigidly flex
clenched fists
extended legs

Back 174

decorticate rigidity

Front 175

arms and legs extend and pronate particularly on side opposite primary lesion
extensor muscles in all of limbs and those of trunk/neck have increased tone due to increased activity of alpha motor neurons innervating extensor muscles and increased gamma motor neurons

Back 175

decerebrate rigidity

Front 176

tonic neck reflexes occur with what kind of posturing?

Back 176

decorticate

Front 177

in ________ decorticate posturing progresses to decerebrate posturing

Back 177

herniation syndrome
especially uncal (transtentorial) herniation can cause a progression of decorticate to decerebrate posturing

Front 178

a lesion ABOVE the red nucleus results in

Back 178

decorticate posturing and flexor spasticity

Front 179

a lesion BELOW red nucleus results in

Back 179

decerebrate posturing or extensor spasticity

Front 180

function of motor cortex

Back 180

voluntary and fine control of distal musculature
purposeful, flexible motor strategies to achieve a fixed goal
external stimulus is not needed to plan and initiate movement

Front 181

all pyramidal neuron cell bodies reside where?

Back 181

cortical lamina V

Front 182

Brodmann's are 4
MI: lowest current threshold, elicits contralateral movement

Back 182

primary motor cortex

Front 183

Brodmann's area 6
MII: higher threshold
often elicits bilateral limb movement

Back 183

premotor cortex

Front 184

called SI, areas 3,1,2
especially 3a receives input from muscle spindle

Back 184

primary somatic sensory cortex

Front 185

what cells have the largest somas in CNS

Back 185

Betz
subset of principial primary motor cortex pyrimidal neurons in area 4

Front 186

__________may be the earliest form of supraspinal control by the CST.

Back 186

projection to dorsal horn

Front 187

CST terminates widely within

Back 187

spinal gray matter

Front 188

CST reflex control of:

Back 188

nociceptive
somatosensory
reflex
autononomic and somatic motor function

Front 189

CST projections are an important source of presynaptic inhibition of:

Back 189

primary sensory afferents

Front 190

what tract is unique in primates in its ability to control fine finger movements?

Back 190

corticospinal tract

Front 191

receives input from stretch receptors
presynaptic inhibition of primary afferent fibers

Back 191

lamina VII, intermediate zone

Front 192

in primates direct projection to alpha and gamma motor neuron in

Back 192

lamina IX, motor nuclei

Front 193

two mechanisms for maintenance of balance and posture

Back 193

feedback and feedforward

Front 194

what reflex modulates learned adaptive postural control?

Back 194

feedforward

Front 195

a muscle activation pattern that is a response to sensory signals resulting from postural instability
aka unanticipated postural instability

Back 195

feedback response

Front 196

activity of trunk/limb muscles that occurs before voluntary movement to prepare body for any disturbance to posture
aka anticipated postural instability

Back 196

feedforward response --can originate from motor cortex

Front 197

function of direct motor pathways

Back 197

transmits executive commands for volitional movements

Front 198

function of indirect motor pathways

Back 198

corticofugal projections to brainstem motor centers working in concert to maintain balance and posture

Front 199

what are the sensory inputs of postural instability that leads to input for postural adjustment?

Back 199

proprioceptive
visual
vestibular

Front 200

direct pathways include what tracts?

Back 200

lateral and ventral corticospinal tracts
corticobulbar tracts

Front 201

indirect or extrapyramidal pathways include

Back 201

somatic motor tracts other than corticospinal/corticobulbar
-originate from: motor cortex, basal ganglia, thalamus, cerebellum, RF, nuclei in brainstem
-modulate flexor and extensor muscle tone and reflexes
ie. lateral/medial reticulospinal tracts

Front 202

feedforward reflex

Back 202

modulates learned adaptive postural control
can alter stretch reflex sensitivity (increase or decrease)
preactivation of muscle groups for maintenance of body posture

Front 203

postural set

Back 203

task-specific, feedforward motor readiness to respond as would occur with a runner getting set on their mark
automatic postural adjustment

Front 204

central pattern generators

Back 204

neural circuit capable of producing repetitive activity in the absence of any sensory input
-possess rhythmic predetermined neural activity for activities such as breathing, chewing, walking
walking can be elicited from an isolated spinal cord

Front 205

CPG for walking in isolated human spinal cord

Back 205

Isolated human spinal cord has the capability of generating locomotor-like activity.
Electrical stimulation of the lumbar spinal cord in paraplegics can induce rhythmic, alternating stance and swing phases.

Front 206

medial (dorsal) premotor cortex is active with

Back 206

initiation of movement from internal cues
initiates spontaneous movements

Front 207

lateral (ventral) premotor cortex is active at

Back 207

appearance of external cue
generates a readiness potential in response to external cue

Front 208

what part of the cortex is activated from memory of motor activity?

Back 208

medial (dorsal) premotor cortex

Front 209

lesion of primary motor cortex causes

Back 209

paresis
weakness

Front 210

lesion of premotor areas

Back 210

apraxia of movement - impaired ability to develop strategy for movement

Front 211

parietal cortex, non dominant hemisphere usually right MCA lesion

Back 211

agnosia
neglect

Front 212

parietal cortex, dominant hemisphere usually left MCA lesion

Back 212

aphasia
apraxis of speech - loss of motor vocalization (Broca's area)

Front 213

Broca's aphasia is also

Back 213

motor aphasia

Front 214

Wernicke's aphasia is also

Back 214

receptive aphasia

Front 215

what artery provides the broca's area and wernicke's area

Back 215

left MCA

Front 216

MCA provides blood supply to head and neck areas of the motor and sensory cortical strips
damage to these cortical areas on either side of brain can impair

Back 216

motor speech
swallowing functions

Front 217

superficial reflexes occurring in response to scraping of the skin

Back 217

Babinski
abdominal reflexes

Front 218

abdominal reflex

Back 218

contraction of abdominal muscles in quadrant of abdomen that is stimulated by scraping the skin tangential to or toward the umbilicus
contraction can often be seen as a brisk motion of umbilicus toward the quadrant that is stimulated