2008 Fall Neuro Test 4: Motor Systems 1 & 2 Vcu Dpt

Front 1

Typically motor neurons are of this type and innervate this structure

Back 1

Alpha motoneurons, Skeletal muscle fibers

Front 2

Another type of motoneuron is ___ and those innervate ___

Back 2

Gamma motoneurons, Innervate muscle fibers within sensory receptors called muscle spindles

Front 3

Central Pattern Generators

Back 3

A special group of interneurons where excitation of a few motoneurons in the spinal cord of brain stem results in coordinated multi-segmental motor activities such as gait. Cyclical motor patterns

Front 4

Interneurons and to a lesser extent motoneurons receive input from _____, and descending pathways from:______, _________, ________, _____, _______

Back 4

Sensory receptors
Cerebral cortex
Vestibular nuclei
Reticular Formation
Red nucleus
Superior Colliculus (tectum)
Collaterals of motoneurons

Front 5

Basal nuclei work in:

Back 5

Preparation (planning) and execution of movements, including adjusting for amplitude and velocity
Also control in mood in cognition?

Front 6

Four Cortical motor areas

Back 6

1. Primary Motor area
2. Secondary (Supplementary and premotor)
3. Parietal
4. CInculate gyrus

Front 7

Cortical motor areas communicate with each other:

Back 7

within and across hemispheres

Front 8

Cortical motor areas receive somatosensory info from:

Back 8

Sensory and Association cortical regions (Decision-making areas), Ascending pathways via the thalamus (primarily VPL and VPM)

Front 9

path of the circuit linking cortical motor areas to cerebellum and back

Back 9

Cortex to Pontine nuclei to Cerebellum (via Middle Cerebellar Peduncle) to VL and VPL thalamic nuclei back to M1 (primary motor cortex)

Front 10

Circuit linking cortical motor areas to basal nuclei

Back 10

Cortex to Neostriatum to Globus Pallidus to VA and VL thalamic nuclei primarily to Supplementary Motor Area

Front 11

Hypothesized function of M1

Back 11

Execution of specific well-defined motor responses. Populations of neurons code for
1. Force of contraction
2. Movement direction (flexion v. extension)

Front 12

Primary origin of M1 long projection fibers (molecular layer-wise)

Back 12

Pyramidal Cells in layer V

Front 13

Location of Supplementary Motor Area

Back 13

Rostral to M1, more dorsal than PreMC

Front 14

Location of Premotor Cortex

Back 14

Rostral to M1, more Ventral than SMA

Front 15

Functions of Secondary Motor Areas (Supplementary Motor and Premotor)

Back 15

1. Planning of movements
2. Initial phase of movements (orienting body and limbs)
3. Control of proximal and axial muscles during distal movements

Front 16

SMA and PreMC project to:

Back 16

1. M1
2. Reticular formation
3. Spinal Cord

Front 17

Central gait patterns are circuits of

Back 17

Interneurons

Front 18

Primary Motor Cortex especially controls _____ movements

Back 18

Distal

Front 19

Random finger movements stem from this part of the cortex

Back 19

M1

Front 20

Purposeful, goal oriented finger movements planned and executed in a specific order stem from using this part of the cortex:

Back 20

M1 in combo with SMA

Front 21

Movement planned but not executed is from this part of the cortex

Back 21

Supplementary Motor Area

Front 22

Isolated Primary Motor Cortex lesion causes:

Back 22

Contralateral paresis of voluntary movements. Usually starts as flaccid but may become spastic.
Sufferers often regain movement of proximal limbs but distal muscles remain paralyzed.
Synergistic movements lack control.

Front 23

Isolated lesion to SMA and PreMotor Cortex results in:

Back 23

Apraxia: difficulty using the limb appropriately during tasks.
Automatic vs. Purposeful movements.

Front 24

Posterior Parietal Association Area is also known as Brodmann's Areas ___ + ___

Back 24

5 and 7

Front 25

Posterior Parietal Association Cortex motor-related functions:

Back 25

-Planning movement based on visual and somatic sensory info
-Intitiation of movements (overlap with SMA)
- Motor related output primarily to SMA and PreMC

Front 26

Sensory related functions of Posterior Parietal Association Area

Back 26

Integrates visual, somatosensory and vestibular information

Front 27

Lesion of Posterior Parietal Association Cortex would cause these sensory inabilities

Back 27

- Greatest effects on nondominant hemisphere
- Various agnosias (inability to form mental image of objects that are palpated with the opposite hand)
- Inability to associate tactile stimuli with visual image
- inability to attend to the contralateral world if severe Non-Dominant lesion

Front 28

Lesion of Posterior Parietal Association Cortex would cause these motor deficits

Back 28

- Reduced initiation of movements of the contralateral limb
- deficits in movements guided by visual and tactile stimuli

Front 29

Cingulate motor area has a possible role in

Back 29

motivation or emotional movements

Front 30

Frontal, parietal and supplemental eye field work with motor how?

Back 30

Coordinating eye movement related to visual tracking. Voluntary override of visual reflexes

Front 31

Motor Control pathways beginning with "Cortico-"

Back 31

-Spinal
-nuclear/bulbar
-striate
-rubral
-reticular
-pontine

Front 32

Lateral descending motor pathways terminate (in Spinal Cord)

Back 32

more laterally within the anterior horn

Front 33

Lateral descending motor pathways include

Back 33

Lateral cortocospinal tract and rubrospinal tract

Front 34

Rubrospinal tract originates in:

Back 34

red nucleus

Front 35

Medial descending motor pathways affect these muscles

Back 35

Proximal musculature (greater effect on)

Front 36

Medial descending motor pathways terminate

Back 36

more medially within the anterior horn

Front 37

Medial descending motor pathways control

Back 37

balance, proximal stability, head position, etc

Front 38

Medial descending motor pathways include:

Back 38

anterior corticospinal
Vestibulospinal
Reticulospinal
Tectospinal

Front 39

Brodmann's Area 4

Back 39

M1. Contributes approximately 30% of axons of Corticospinal tract

Front 40

Brodmann's Area 6

Back 40

SMA and PreMotor Cortex.
Together contribute about 30% of corticospinal tract neurons

Front 41

Course of the Corticospinal Tract

Back 41

Cortex -> Posterior Limb of Internal Capsule -> Crus Cerebri (which has its own somatotopy)-> Basilar Pons -> Pyramids of medulla -> 85% decussate in the caudal medulla -> lateral corticospinal (somatotopy is upper extremity more medial) or anterior corticospinal tracts

Front 42

Motor Corticospinal fibers run from ____, ____, and ____ (parts of the cortex)

Back 42

M1, SMA, and PMC

Front 43

Corticospinal fibers terminate in what part of the spinal cord? What laminae?

Back 43

Anterior regions, esp. L VII, VIII, and IX (7, 8, and 9)

Front 44

Lateral Corticospinal tract has the greatest effect on

Back 44

distal muscles

Front 45

Anterior Corticospinal tract has the greatest effect on ____ and is often ___

Back 45

proximal muscles, bilateral

Front 46

Corticospinal Motor Functions:

Back 46

Drive coordinated, integrated, highly controlled activities, esp. of the distal extremity. Also initiation and modulation of central pattern generators.

Front 47

Parietal (sensory cortices) Corticospinal fibers act as

Back 47

Descending pathway modulators

Front 48

Parietal (sensory cortices) Corticospinal fibers terminate on

Back 48

Posterior horn of Laminae IV-VI of spinal cord

Front 49

Collaterals from the Corticospinal tract go to:

Back 49

Reticular formation (pons and medulla)
Inferior olivary nucleus
Posterior Column nuclei

Front 50

Rubrospinal tract (remember it's in "lateral system") seems to mostly impact:

Back 50

distal movements

Front 51

the red nucleus is influenced by

Back 51

Motor areas of cerebral cortex and cerebellum

Front 52

Pons arterial supply

Back 52

- paramedian branches of the basilar artery
- anterior spinal artery

Front 53

Rubrospinal tract terminates :

Back 53

on contralateral cervical spinal cord

Front 54

Rubrospinal tract primarily influences

Back 54

contralateral elbow and wrist flexor musculature

Front 55

Lateral Vestibulospinal tract Origin:

Back 55

Lateral vestibular nucleus

Front 56

Lateral Vestibulospinal tract terminates (ipsi or contralaterally)

Back 56

on the Ipsilateral spinal cord

Front 57

Function of the lateral vestibulospinal tract

Back 57

postural adjustment of trunk and LE, maintaining balance
- orientation of head in space.

Front 58

Generally, the lateral vestibulospinal tract ___(excites/inhibits)___ the motoneurons of the __(part of the body) (flexors/extensors)__ and the _____ (muscles)

Back 58

Excitates
LE and trunk extensors
Paravertebral muscles

Front 59

Medial vestibulospinal tract origin:

Back 59

Medial Vestibular nucleus

Front 60

Medial vestibulospinal tract terminates

Back 60

bilateral cervical and upper thoracic spinal cord

Front 61

Function of the medial vestibulospinal tract

Back 61

Reflex adjustments of the head position in response to activity in the vestibular apparati

Front 62

The two reticulospinal tracts

Back 62

Pontine (medial) and medullary (lateral)

Front 63

Motor Functions of reticulospinal tract(s)

Back 63

-Control and modulate esp: paravertebral and limb extensor muscles
- postural adjustment and balance
- modulation of segmental reflexes
- eye-head coordination
-modulate activity of gamma (muscle spindle sensitivity) and alpha motoneurons

Front 64

Sensory functions of reticulospinal tracts

Back 64

modulate noxious (pain) information

Front 65

Reticulospinal tracts terminate on these Laminae in the spinal cord in this fashio

Back 65

VII and VIII
bilaterally with ipsilateral predominance

Front 66

Pontine (medial) reticulospinal pathway is considered to have a predominately ______ effect on motoneurons

Back 66

Excitatory

Front 67

Medullary (lateral) reticulospinal tract is considered to have a predominately __________ effect on motoneurons

Back 67

Inhibitory

Front 68

Reticular formation nuclei that serve as origin for Reticulospinal tract (influencing motor function) receive motor information from:

Back 68

Motor regions of the cerebral cortex (corticoreticular fibers) and the cerebellum

Front 69

Reticular formation nuclei that serve as origin for Reticulospinal tract (influencing motor function) receive SENSORY information from:

Back 69

Collaterals from sensory pathways conveying vestibular, visual, auditory and somatic sensory information

Front 70

Tectospinal tract origin and termination

Back 70

Superior colliculus to contralateral ventral cervical spinal cord

Front 71

Tectospinal tract function:

Back 71

Coordinates head, neck and eye movements particularly in response to visual stimuli

Front 72

Corticonuclear (corticobulbar) pathways course:

Back 72

from Supplementary Motor area and Parietal lobe through genu of internal capsule through crus cerebri (medial to the corticospinal tract) to terminate on the motor nuclei of the brainstem (facial, trigeminal, nucleus ambiguous, and hypoglossal)

Front 73

Corticonuclear pathway(s) act(s) on these muscles

Back 73

Sternocleidomastoid and Trapezius

Front 74

If the corticonuclear pathway is sectioned above the facial motor nucleus, what happens to the face?

Back 74

Contralateral lower face paralysis

Front 75

If a lesion of the corticonuclear pathway occurs above the nucleus ambiguous and hypoglossal nucleus (what happens with the uvula and the tongue):

Back 75

Uvula deviates toward the side of the Lesion
Tongue points away from the side of the lesion

Hint 75

fibers have already crossed from the facial motor cortex

Front 76

Medial Motor Systems control

Back 76

Proximal and axial muscles, balance and orientation of head

Front 77

Reticular formation receives info from

Back 77

Corticoreticular motor regions of the cortex
Cerebellum
Collaterals from sensory paths
Spinoreticular tract from ALS

Front 78

Sensory info to Reticular Formation

Back 78

visual, auditory, vestibular, somatic

Front 79

Tectospinal tract initiates reflex movement of:
for:

Back 79

reflex movements of head and neck in response to visual, auditory, and painful stimuli

Front 80

Corticonuclear tract terminations

Back 80

Trigeminal motor nucleus
-- Muscles of mastication
Facial motor nucleus
-- Muscles of facial expression
Nucleus ambiguus
-- Larynx, pharynx, upper esophagus
Hypoglossal
-- tongue
Spinal accessory
-- Trapezius, SCM

Hint 80

5 nuclei

Front 81

Deficit If corticonuclear tract lesion is BELOW facial motor nucleus

Back 81

Entire 1/2 of contralateral face is paralyzed
ex: Bell's Palsy

Front 82

Typical signs of lesion of corticospinal and other descending tracts (above brain stem)

Back 82

Initially:
flaccid muscle
Often Develop:
Spasticity / hypertonicity
increased resistance to passive stretch
hyperreflexia & possibly clonus
Babinski sign – upward big toe
Synergistic movement patterns of groups of muscles

Front 83

If a lesion occurs in the Internal Capsule can you isolate a muscle?

Back 83

No, you will move synergistically in a pattern of groups of muscles.

Front 84

(Experimental) lesion between superior and inferior colliculi results in

Back 84

Decerebration

Front 85

Decerebration means:

Back 85

- Unopposed rigid extension of all extremities
- desctruction of all descending cortical projections and rubrospinal projections
- RETAIN reticulospinal and vestibulospinal tracts, hence the limb extension

Front 86

Decorticate rigidity is a result of a lesion here:

Back 86

Immediately rostral to the superior colliculus

Front 87

Decorticate rigidity posturing looks like this:

Back 87

Upper Extremity flexion with Lower Extremity extension

Front 88

With Decorticate rigidity, what tracts are intact (causing flexion of upper extremity, LE extension)

Back 88

Red Nucleus/Rubrospinal tract is intact
Reticular Formation is also intact and driving Lower Extremity extension

Front 89

What is severed with decerebration that is not severed with decortication?

Back 89

Rubrospinal tract

Front 90

2 tracts that are retained with decerebration

Back 90

Reticulospinal
Vestibulospinal

Front 91

Vestibulospinal tract functions:

Back 91

The medial part of the vestibulospinal tract project bilaterally down the spinal cord and triggers the cervical spinal circuits, controlling a correct position of the head and neck.

The lateral part of the vestibulospinal tract projects ipsilateral down to the lumbar region. There it helps to maintain an upright and balanced posture by stimulating extensor motor neurons in the legs.

Front 92

Decortication involves severing of these tracts:

Back 92

Cortical projections including corticorubral

Front 93

A motor unit is the

Back 93

motoneuron and all the muscle fibers it innervates

Front 94

Stereognosis

Back 94

Shape perception

Front 95

Mechanoreceptors are found in these places:

Back 95

joint capsules,
ligaments,
menisci, etc
muscle
tendon
Skin & subcutaneous tissues

Front 96

Slowly adapting joint receptors are:

Back 96

Type I: Ruffini endings
Type III: (“Golgi Tendon Organ-like”)
Type IV: Free Nerve Endings (C and A-delta fibers)

Front 97

A rapidly adapting joint mechanoreceptor

Back 97

Type II: Lamellated corpuscle / Pacinian corpuscle

Front 98

Type II Lamellated corp. / Pacinian corpuscles are located in ___
are _____ adapting
and detect _____

Back 98

-most joint structures
- rapidly!
- changes in direction and speed of joint movement

Front 99

Type I mechanoreceptors are called

Back 99

Ruffini endings

Front 100

Ruffini endings are ____ adapting

Back 100

slowly

Front 101

Ruffini endings give information mostly

Back 101

at the extremes of movement

Front 102

GTO-like receptors are ____ adapting

Back 102

slowly

Front 103

GTO-like adaptors are found in

Back 103

Ligaments and horns of menisci

Front 104

GTO-like adaptors give information regarding

Back 104

extreme joint movement
stretch

Front 105

What primary joint mechanoreceptors would be active if you sprained your ankle ligaments

Back 105

GTO-like adaptors

Front 106

Kinesthesia means

Back 106

sensing direction and force of limb movement

Front 107

Free Nerve endings are Type ___ receptors

Back 107

IV

Front 108

Higher density of receptors are for these tasks

Back 108

Fine tasks, fine motor skills

Front 109

Golgi tendon organs give info about

Back 109

Muscle course

Front 110

GTOs are located at the ____

Back 110

Musculotendinous junction

Front 111

Muscle spindle location

Back 111

attached to and in parallel with extrafusal fibers

Front 112

Function of Muscle spindles

Back 112

Provide information to the CNS regarding muscle length and changes in muscle length (static and dynamic information)
Therefore helping to determine limb position

Front 113

CNS can adjust the ____ of muscle spindles

Back 113

sensitivity

Front 114

From the muscle spindle, Type II fibers synapse on ______ fibers
and type Ia synapse on ___

Back 114

alpha motor fibers
gamma motor

Front 115

Type II fibers from a muscle spindle ultimately affect _____
while type Ia fibers affect:

Back 115

Skeletal muscle (extrafusal)
Intrafusal (nuclear chain) fibers

Front 116

Intrafusal and ____ fibers generally contract simultaneously

Back 116

Extrafusal / so as to maintain muscle spindles in appropriate tautness within muscle

Front 117

gamma motoneuron activation (and intrafusal muscle shortening) is greater with tasks that require

Back 117

precise movements

Front 118

The four control centers of the gamma nuclei

Back 118

near red nucleus
reticular formation
vestibular nuclei
substantia nigra pars compacta

Front 119

Definition of a reflex

Back 119

Involuntary stereotyped response to specific sensory stimuli

Front 120

Stretch reflex is also called

Back 120

The Deep Tendon reflex

Front 121

The stretch reflex occurs as a muscle is stretched and sends a TYpe _____ afferent to the spinal cord to synapse on a ______ motoneuron

Back 121

Type Ia
Alpha Motoneuron

Front 122

Only the ___ of intrafusal muscle fibers are active

Back 122

ends

Front 123

Primary endings of muscle spindle nerve fibers give us info about

Back 123

CHanges in length of a muscle

Front 124

If lesion of the Lateral Striate Arteries - br of middle cerebral artery...

Back 124

Posterior limb and genu of Internal Capsule would be ineffective, affecting:
-corticospinal
-corticonuclear
-thalamocortical fibers
- possibly retrolenticular & sublenticular fibers

Front 125

Thalamocortical fibers function:

Back 125

sensory loss
contralateral hemianesthesia

Front 126

Muscle spindle afferents act as ____ stretch receptors

Back 126

passive

Front 127

The gamma loop pathway

Back 127

1. Gamma activation
2. contraction of intrafusal fibers
3. Stretch of central region of intrafusal fibers
4. EPSPs to alpha motoneuron which if sufficient will result in
5. Activation of alpha motoneuron
6. Contraction of extrafusal muscle fibers

Front 128

Thalamocortical fiber disruption would result in:

Back 128

Sensory loss
Contralateral hemianesthesia

Front 129

retrolenticular & sublenticular fibers disruption would result in:

Back 129

Visual deficits
Auditory deficits

Front 130

2 lower extremity multisynaptic reflexes

Back 130

Flexor withdrawal
Crossed extensor

Front 131

The clinical helpfulness of the stretch reflex is that it helps

Back 131

determine peripheral v. central lesion
absence/weakness: peripheral injury
hyperactive response: typically central

Front 132

Ataxia

Back 132

Loss of motor coordination
unsteady gait, tend to fall twd side of lesion

Front 133

Dysmetria

Back 133

Loss of coordination
hypermetria -- overshooting intended goal
hypometria -- undershooting goal

Front 134

Dysarthria

Back 134

unable to articulate in words (can't control tongue)

Front 135

Dysdiadochokinesia

Back 135

cannot rapidly change the direction of movement

Front 136

Reticular formation location

Back 136

poorly-differentiated area of the brain stem, centered roughly in the pons. The reticular formation is the core of the brainstem running through the mid-brain, pons and medulla

Front 137

The ascending reticular activating system connects to

Back 137

areas in the thalamus, hypothalamus, and cortex, while the descending reticular activating system connects to the cerebellum and sensory nerves.