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Flashcards in Neuro3 Deck (222):
1

Where, in the brain, is the decision to move (somatic motor) made?

Heteromodal association cortices
(prefrontal, parietotemporal, or limbic)

2

Where, in the brain, are the cortical motor planning regions?

Premotor cortex
Supplementary motor cortex
Frontal eye fields
Broca's area

3

What occurs after motor planning decision has been made?

Control circuits refine and assist with execution

4

Where are the motor control circuits?

Primary motor cortex, cerebellum, and basal ganglia

5

What are 7 primary descending motor pathways?

Corticospinal
Corticobulbar
Reticulospinal
Rubrospinal
Vestibulospinal
Tectospinal

6

The descending motor neurons are UPN/LMN?

UPN's

7

What to the descending pathway axons synapse with?

Interneurons (in the gray matter) and LMN's in the Ventral Horns

8

In most of the body, the LMN synapse is in the ______, but cranial nn. synapse in the ______.

Ventral horns of the spinal tract
In the nuclei of the brain.

9

From what supra spinal structures do descending pathways originate?

Cortex and brainstem (neuronal cell bodies)

10

T/F
Descending pathways usually synapse directly (monosynaptically) onto Alpha/Gamma MN's in ventral horn of the spinal cord and cranial motor nuclei.

False.
Most (a majority) synapse with interneurons in the spinal cord.

11

What other input do alpha and gamma MN's receive?

segmental inputs from peripheral afferents

12

Descending motor pathways can be both/and?

Excitatory
Inhibitory

(these pathways shut off certain mm.'s and activate others)

13

What dictates the excitatory/inhibitory make-up of these descending motor pathways?

spatial and temporal summation with thousands of inhibitory/excitatory interneurons.

14

The alpha/gamma motor neurons are considered to be...

LMN's

15

The descending pathways, along with the somas they arise from, are considered to be...

UPN's

16

What is the largest and clinically most important spinal tract?

The Corticospinal Tract

(aka - pyramidal tract)

17

Where do the axons of the primary motor tract originate?

From somas mostly in the primary motor cortex

18

Describe the pathway of the Corticospinal Tract from the brain to spinal cord.

Primary motor cortex > Corona Radiata > Internal Capsule > Cerebral peduncles > Pyramids

19

What percentage of fibers from the Corticospinal tract decussate in the medullary pyramids?

85-90%

20

Where do the crossed (85-90%) axons travel through the spinal cord?

Lateral Corticospinal Tract
(lateral funiculus)

21

What percentage of corticospinal tract fibers have monosynaptic connections?

3-5%

22

Where do the uncrossed (10-15%) fibers in the corticospinal tract descend?

Anterior Corticospinal tract
(anterior funiculus)

23

What tract is regarded as the descending pathway most concerned with voluntary, discrete, skilled movements?

Lateral Corticospinal tract

(the crossed one in the majority)

24

What tract controls bilateral axial musculature?

Anterior Corticospinal tract

25

What do Corticobulbar tracts innervate?

Cranial nn.'s

26

Describe the general pathway of a Corticobulbar tract.

Somas of motor cortex > corona radiata > internal capsule > cerebral peduncles > cranial nn.'s

27

Which CN's are innervated by Corticobulbar tracts?

III
IV
V
VI
VII
IX
X
XI
XII

28

Which CN's aren't innervated by Corticobulbar tracts?

I, II, VIII

29

What Corticobulbar tract is NOT crossed?

VII - facial nucleus

is bilateral

30

What are 2 functions of the Rubrospinal Tract?

Skilled dextrous movements of the upper extremity

Alternate route for achieving voluntary movement

31

Describe the pathway of the Rubrospinal Tract.

Cerebral Cortex and Cerebellum > Red nucleus > cross in Ventral Tegmentum as exit > Lateral funiculus

32

Where, specifically, does the Rubrospinal tract run in the spine?

Just anterior to the Lateral Corticospinal Tract

(in lateral funiculus)

33

What are the 2 Reticulospinal Tracts?

Pontine
Medullary

34

Where are the reticular spinal formation regions?

Pons and Medulla

35

What is the Medullary Reticulospinal tract also called, and what is its function?

aka Lateral Reticulospinal Tract

inhibits lower extremity extensors/facilitates flexors

36

What does the medullary reticulospinal tract do in terms of tone to the lower extremities?

Reduces muscle tone

37

T/F
The medullary reticulospinal tract is crossed.

False
It descends both crossed and uncrossed

38

The Pontine reticulospinal tract is also called..

aka Medial reticulospinal tract

39

Is the Pontine reticulospinal tract mostly crossed or uncrossed?

Mostly UNcrossed

(so they synapse ipsilaterally)

40

What is the target of the Pontine reticulospinal tract?

Lower extremity extensors (alpha and gamma)

41

Does the Pontine reticulospinal tract increase or decrease tone?

Increases muscle tone

42

What are the 2 Vestibulospinal tracts?

LVST (lateral)
MVST (medial)

43

The LVST and MVST can be thought of as pathways that counteract what force?

Gravity (they are postural)

44

What are 2 inputs to the Vestibular nuclei?

VIII and the cerebellum

45

What is the function of the Ascending nuclei of the vestibulospinal tract?

The vestibuloocular reflex

46

Where does the vestibuloocular reflex travel, and what does it coordinate?

Ascending portion of the MLF (medial longitudinal fasciculus)

Eye and head movements

47

From whence does the LVST arise?

Deiter's Nucleus

48

Does the LVST pathway descend crossed or uncrossed?

UNcrossed

49

What pathway in the spinal cord does the LVST use, and where does it terminate?

Anterior funiculus

All spinal levels

50

What mm.'s does the LVST facilitate?

LE extensors
UE flexors

51

LVST is considered the primary....

Antigravity pathway

52

What is the primary function of the MVST?

Inhibit UE extensors
Facilitate UE flexors

(this is antigravity for the upper extremities)

53

Which spinal tract is involved in turning your head at something novel?

Tectospinal tract

54

Tectospinal tract pathway:

cell bodies in superior colliculus of midbrain > Tegmentum cross > travels with MVST to upper cervical spinal cord > turns head and neck

55

What do descending pathways terminate with?

interneurons and ventral horn motor neurons at different spinal levels.

56

What is the pathway of an LMN?

Ventral horn > ventral root > spinal root and peripheral nn.'s innervating m.

57

T/F
mm.'s are innervated by a single spinal level.

False.
Multiple levels go into many (larger) mm.'s

58

What happens if only 1 or 2 ventral roots are damaged?

Paresis (muscle weakening)

59

When does paralysis occur?

Either all ventral roots innervating a muscle are destroyed or UMN's damaged by a stroke.

60

What is the diaphragm innervated by?

C3-5

meaning lesion above C3 leaves pt on ventilator
(345 stay alive)

61

T/F
Most spinal cord lesions affect bowel and bladder.

True
these are low (S2-4)

62

What motor neurons have large diameter, travel fast, and innervate extrafusal (motor unit) muscle?

Alpha MN

63

What motor neurons travel slow, have a small diameter, and innervate muscle spindle?

Gamma MN

64

Are Gamma MN's myelinated?

yes. but not as thick as alphas

65

What are the two types of autonomic fibers?

B-motor (pre-ganglionic) lightly myelinated
C-motor (post-ganglionic) unmyelinated

(told us to cross this question/table off)

66

What do Gamma MN's do to muscle, say, before a race?

Set tone. Gamma's fire a lot in response to anticipated exertion. Once exertion begins, Alpha MN's kick in.

67

What are the 5 separate nuclei that make up the basal ganglia?

Caudate
Putamen
Globus pallidus
Subthalamic nucleus
Substantia nigra (pars reticula and pars compacta)

68

What separates the caudate and the putamen?

The internal capsule

69

What are the two parts of the globus pallidus?

Externa and Interna

70

Is the nucleus Accumbens considered to be part of the basal ganglia?

Some think this is the 6th nuclei

71

Caudate + Putamen =

Striatum (or neostriatum)

72

Caudate + Putamen + Globus =

Corpus striatum

73

Putamen + Globus =

Lenticulate nucleus

74

What two parts of the brain are the basal ganglia highly connected to?

Cortex and the Thalamus

75

How many "channels" have been identified in the basal ganglia?

4

76

What are some symptoms of lesions to the basal ganglia?

Tremor
Rigidity
Difficulty initiating voluntary movements
Bradykinesia (slow movement)
Ballismus (jerky motions)
Choreoathetoid movements (inlvoluntary)

77

What are the 4 basal ganglia channels?

Occulomotor (eye movements)
Prefrontal (cognitive)
Limbic (emotional)
Motor

78

Do the basal ganglia have direct connections to the motor neurons in the spinal cord?

NO.
stimulation of BG neurons does not directly cause movements (must be a relay area)

79

Do lesions of the Basal Ganglia cause paralysis?

NO

80

What function is the basal ganglia best know for?

Motor

81

What 4 specific functions does the motor channel have in the basal ganglia?

Formulation of general motor plans
Execution of specific motor plans
Scaling of motor intensity
Automatic execution of learned motor plans

82

What does dysfunction of the Formulation component of the Motor channel in basal ganglia cause?

Isolated motor acts only

83

What does dysfunction in the Scaling component of the Motor channel in basal ganglia cause?

Movement at inappropriate rates, amplitudes, and duration

84

What does a dysfunction in the Automatic execution component of the Motor channel in basal ganglia cause?

Much more mental effort must be applied to handwriting, tying shoes, etc.

85

What channel in the basal ganglia is implicated in motivation?

Limbic

(also emotion)

86

Where do the outputs of the basal ganglia (specifically the corpus striatum) go?

Cortex

87

Where are the main inputs to the basal ganglia found?
Where do these inputs originate?

Caudate and Putamen (striatum/neostriatum)
Cortex and Thalamus

88

Are the inputs to the Striatum (caudate and putamen) excitatory or inhibitory?

Excitatory
(glutamatergic)

89

Inputs to the Substantia Nigra pars compacta are...

Domaninergic

90

Where are the main outputs from the Basal Ganglia?

Globus Pallidus Interna
Substantia Nigra pars Reticula

91

Are the main outputs from the Basal Ganglia excitatory or inhibitory?
Where do they go?

Inhibitory (GABAergic)

VL & VA of Thalamus, reticular formation, and superior colliculus

92

What other neurons in the Striatum (caudate and putamen) also play an important role in BG function?

Acetylcholinergic

93

What are the 2 main pathways of functional circuitry in the BG, and what modulates them?

Direct (excitatory) and Indirect (inhibitory)

Substantia Nigra circuit modulates.

94

What is the end result of Direct Pathway stimulation for the motor, prefrontal, and limbic channels?

Increased movement
Increased cognitive function
Increased emotions

95

Direct pathway of the BG:

Cortex (excitatory) > Caudate/Putamen (Inhibitory) > GPi/SNr turned off > Thalamus excitation from other stimuli > cortical stimulation

The Globus pallidus interna and Substantia Nigra can no longer inhibit the Thalamus, opening it to other stimuli

96

The Direct Pathway of the BG is excitatory/inhibitory?

Excitatory

97

The Indirect Pathway of the BG is excitatory/inhibitory?

Inhibitory

98

What is the end result of Indirect Pathway stimulation in the BG for the motor, prefrontal, and limbic channels?

Decreased movement, cognitive function, and emotions

99

Indirect pathway of the BG:

Cortex (excitatory) > Caudate/Putamen (inhibitory) > Globus Pallidus Externa

GPe can no longer inhibit the Subthalamic nuclei

Subthalamic nuclei (now excited by other input) > Globus Pallidus Interna/Substantia Nigra pars reticulata

GPi/SNr now excited for inhibitory action of Thalamus

Thalamus (now inhibited) > BLOCKS thalamic excitation of the cortex

100

SNc stands for:

Substantia Nigra pars compacta

101

What is the neurotransmitter for the SNc (nigrostriatal) pathway?

dopamine

102

Dopamine is _______ to the Direct pathway neurons in the Caudate/Putamen and ________ to the Indirect pathway of the Caudate/Putamen.

Excitatory
Inhibitory

103

What is the downstream effect of the nigrostriatal (SNc) pathway firing ?

Excitation of the direct pathway
Inhibition of the indirect pathway

so, increased movement, emotions, and cognitive functions

104

Which pathway has D1 receptors?

Direct

105

Which pathway has D2 receptors?

Indirect

106

Do lesions of the basal ganglia cause paralysis?

NO

107

What is Bradykinesia

slow movements

cardinal sign of parkinson's

108

What is Athetosis?
What is it associated with?

involuntary twisting movements

Huntington's disease, perinatal hypoxia, antipsychotic meds, anitemetic meds, Levadopa

109

What is Chorea?
What is it associated with?

Involuntary fluid (dancelike) movements

Huntington's disease, perinatal hypoxia, antipsychotic meds, anitemetic meds, Levadopa, infarct/focal lesions of basal ganglia, lupus

110

What causes Ballismus?

usually unilateral lesion causing contralateral, involuntary, large flinging movements

111

T/F
Tremors usually vary in frequency

False
Tremors usually have specific frequency of movement

112

What is the difference between Rigidity and Dystonia?

Rigidity is resistance to passive movement of limb
Dystonia refers to the assumption of distorted positions in limbs, trunk, or face.

113

What lesions of the BG cause Bradykinesia and Akinesia?

Substantia Nigra and Globus Pallidus Externa

114

If a lesion takes out the Putamen (specifically the Indirect pathway), what results?

Hyperkinesia
Chorea
Athetosis

115

What do lesions of the Caudate nucleus cause?

Few movement issues
but, cognitive, emotional, and complex behaviors affected

116

What does a lesion in the Subthalamic nucleus cause?

Hemibalismus

117

What causes the abnormal movements of PD?

Removal of inhibitory influences on them

118

What are the 4 cardinal features of PD?

Tremor
Rigidity
Bradykinesia
Postural instability

119

T/F
PD tremors mostly occur when at rest

True,
although some pts have action tremor as well (this is tremor during movement rather than at rest)

120

What 2 types of rigidity are expressed in PD?

lead pipe and cog wheel

121

What is the most disabling feature of PD?

Bradykinesia

122

What are the 3 main pharmacological treatments for PD and how do they work?

Monoamine oxidase inhibitors (prevents breakdown of dopamine)

Dopamine agonist drugs (mimics dopamine)

L-DOPA (precursor to dopamine that crosses BBB)

123

Why would a DOPA decarboxylase inhibitor (drug called Sinemet) benefit recipients of L-DOPA?

It prevents L-DOPA conversion to dopamine in the plasma, increasing efficiency of delivery

124

What is the general term for movements indicating the failure of L-DOPA?

dyskinesias

(including head bobbing, lip smacking, tongue thrusting, etc)

125

What are 2 surgical treatments for PD?

Deep Brain Stimulation
Ablations (surgical lesions)

126

What type of charge does Deep Brain Stimulation deliver?
What does it do?

Continuous
reduces discharge of action potentials and rebalances control messages

127

Where is the electrode placed in DBS for disabling dyskinesias and tremor?

Globus Pallidus

128

Where is the electrode placed in DBS to reduce bradykinesia, tremor, and rigidity?

Subthalamic nucleus

129

Does successful DBS alleviate all the symptoms of PD?

No. Only some symptoms, and doesn't slow progression of disease.

130

What are the 2 ablations (surgical lesions) used to treat PD?

Thalamotomy (small area of thalamus to treat tremor)
Pallidotomy (globus pallidus to treat akinesia)

131

What is a primary symptom of Huntington's disease?

Chorea - uncontrolled, rapid, dance-like

132

What causes the symptoms of Huntington's?

Loss of cholinergic and GABA-ergic neurons in the striatum (causes choreiform movements)
Loss of cortical cells thought to cause impaired cog. functions and dementia

133

What disorder is caused by vascular infarct, hemorrhage, or tumor of the subthalamic nuc.?

Ballism or Hemiballism

134

Does the cerebellum have any direct connections with spinal cord ventral horn motor neurons?

NO

135

What type of sensory input does the Cerebellum constantly receive?

body position, rate of movement, muscle length/force

136

What are 3 symptoms of cerebellar dysfunction?

Ataxia (loss of full control of body movements)
Hypotonia (low muscle tone)
Intention tremors (loss of muscle synergy)

137

Name 4 general functions of the cerebellum?

Compare actual/intended movements
Plan sequential movements
Learn coordinated movements
Produce synergy of movement

138

What separates the anterior and posterior lobes of the cerebellum?

Primary Fissure

139

What makes up the flocculonodular lobe?

2 flocculi
1 nodulus

140

What structure lies lateral to the nodulus and medial to the flocculi?

Cerebellar tonsils

141

Name 4 deep cerebellar nuclei and their targets:

Dentate (cerebrocerebellum)
Globose (spinocerebellum)
Emboliform (spinocerebellum)
Fastigial (vestibulocerebellum)

142

What is the main output pathway of the cerebellum?

Superior Cerebellar peduncle

143

What is the main input pathway of the cerebellum?

Middle cerebellar peduncle

144

What is the pathway of both input and output in the cerebellum?

Inferior peduncle

145

What are the two types of input fibers to the cerebellum?

Mossy fibers
Climbing fibers

146

Where do cortico-ponto-cerebellar tract fibers enter the cerebellum?

middle cerebellar peduncle

147

Where do dorsal and anterior spinocerebellar tract fibers enter the cerebellum?

inferior peduncle (DCST)
superior cerebellar peduncle

148

What pathway is used by axons in the dorsal spinocerebellar tract to enter the cerebellum?

Inferior peduncle

149

Fibers going through the Pons to the cerebellum are termed _______ and fibers going through the Olivary are termed ______.

Mossy
Climbing

150

How many spinocerebellar tracts are there?

4

151

What are the 4 spinocerebellar tracts and what peduncle receives their inputs?

Dorsal - Inferior peduncle
Ventral - Superior peduncle

Spinocuneocerebellar - cuneate nuclei/inferior peduncle
Rostral spinocerebellar - inferior AND superior peduncle

152

Where does the vestibular nerve enter the cerebellum?

Inferior peduncle

153

Climbing fibers entering the cerebellum via the inferior olivary nucleus receive inputs from where?

cortex, basal ganglia, red nucleus, extrapyramidal pathways

154

What peduncle is used by climbing fibers?

Inferior cerebellar peduncle

155

What is the function of the climbing fibers going through the olivary nucleus?

error correction and timing motor tasks

156

Lesions to the cerebellum cause ipsilateral/contralateral deficits?

Ipsilateral

157

What are the 3 cellular layers of the cerebellum?

Molecular
Purkinje
Granular

158

What 4 components make up the molecular layer of the cerebellar cortex?

Stellate cells
Basket cells
Parallel fibers
Dendrites of purkinje cells

159

What three components make up the Granular cell layer?

granule cells
Golgi cells
glomerulus

160

What are the 3 functional divisions of the cerebellum?

Vestibulocerebellum
Spinocerebellum
Cerebrocerebellum

161

Anatomically, what makes up the vestibulocerebellum?

Flocculonodular lobe

162

Vestibulocerebellum:
Inputs/Outputs/Function

Inner ear/visual system via Inferior cerebellar peduncle

Fastigial nucleus > superior/inferior cerebellar peduncles > vestibular nuclei

Equilibrium, eye and head movements, posture


163

Spinocerebellum:
Inputs/Outputs/Function

Spinal cord via superior/inferior peduncles

globose/emboliform nuclei > superior peduncle > reticular formation > contralateral thalamus > contralateral red nucleus

controls ongoing movements/innervates muscle spindles

164

What, anatomically, makes up the spinocerebellum?

Part of Vermis and part of cortices just lateral to Vermis

165

Where, anatomically, is the cerebrocerebellum?

Lateral cerebellar cortices

166

What is the input to the cerebrocerebellum?

cerebral cortex via middle peduncle

167

What is the output of the cerebrocerebellum?

Dentate nuc. > superior cerebellar peduncle > contralateral thalamus

168

What is the function of the cerebrocerebellum?

Formulation of motor plans and initiation of movements

169

What are three major signs of cerebellar dysfunction?

Hypotonia
Disequilibrium
Dyssynergia (there are 8 types listed)

170

What should you relate cerebellar damage to?

Being drunk
alcohol affects cerebellar.
Think roadside test for clinical considerations

171

What are 3 less common terms to classify sensory receptors?

Interoceptors (within body)
Proprioceptors (body position)
Exteroceptors (arise outside body)

172

Name 5 types of receptors:

Chemo
Photo
Thermo
Mechano
Noci

173

Receptors are, by definition...

Transducers

(translate energy and lie at border between outside and inside)

174

T/F
Some receptors are ends of a nerve, some use second messenger systems to stimulate a nerve.

True

175

What do receptor normally require in order to propagate an action potential?

Spatial and Temporal summation - graded - this fires the receptor potential

176

What are the two basic structural categories of cutaneous receptors?

Encapsulated
non-Encapsulated

177

Do all receptors show adaptation to stimulus?

Yes.
Although some rapid, some slow.

178

What class of nerve makes up free nerve endings?

Group III (A-delta) lightly myelinated
or Group IV (C) unmyelinated

179

What class of nerve makes up Hair receptors?

Group III (A-delta) lightly myelinated

180

What class of nerve are Merkel's tactile disks?

A-beta myelinated
mechanoreceptor

181

Where do you find a high density of Meissner's corpuscles and what class of nerve innervates them?

Fingertips
A-beta myelinated axons

182

What type of nerve is good at sensing vibration and is wrapped in layers of lamellae?

Pacinian

183

Pacinian corpuscles are innervated by what class of nerve?

A-beta myelinated

184

What class nerve makes up Ruffini endings?

A-beta myelinated
senses maintained pressure (this is the deep one)

185

How is localization of a stimulus facilitated?

Lateral inhibition

186

What are 4 types of proprioceptors?

Joint
Muscle spindle
Golgi Tendon Organ
Cutaneous mechanoreceptors

187

What 4 types of endings make up joint receptors?

Free
Ruffini's
Pacinian corpuscles
Ligament receptors

188

Skeletal muscle fibers aka
Muscle spindle fibers aka

Extrafusal
Intrafusal

189

What are two terms used to describe intrafusal fibers depending on the arrangement of their nuclei?

Nuclear bag
Nuclear chain

190

What nerve class innervates the nuclear chain fibers?

Group II afferent (flower spray)

191

What nerve class innervates the nuclear bag fibers?

Group 1a

192

The Group II is the ______ response and the Group 1a is the _______ response.

Static
Dynamic

193

What is the MOTOR innervation for the muscle spindle fibers?

gamma MN's

They also set the sensitivity of the spindle

194

The GTO is sensitive to...

Muscle Force (not stretch)

it is 1b afferent

195

List the sensory nerve fiber classifications:

Ia (annulospiral ending from muscle spindle)
Ib (GTO)
II (flower spray on spindle)

A-beta (lower threshold cutaneous mechanoreceptors)
A-delta (aka group III) (nociceptors)
C (aka group IV) (nociceptors)

196

Important things about dermatomes:

C7 marks leading edge of arm
L4-5 marks leading edge of leg
complete anesthesia requires 3 consecutive dorsal roots cut
C1/coccygeal have no dermatomes (no roots)

197

What sensory modalities are carried by the Dorsal Column-Medial Lemniscal and the Trigeminal Lemniscal pathways?

Discriminative touch
2-point touch
vibration
kinesthesis
stereognosis

198

Where are the 1st, 2nd, and 3rd order neurons in the DCML?

1st - DRG A-betas run from peripheral to medulla
2nd - Medial Lemniscus (decussate as internal arcuate fibers, proceeds to thalamus)
3rd - VPL synapse, then thalamocortical projections proceed through corona radiata to cortex

199

Where does DCML fiber enter the spinal cord, and what are they called once they ascend?

Medial regions of Lissauer's tract
Fasciculus gracilis and Fasciculus cuneatus

200

Where are the 1st, 2nd, and 3rd order neurons in the Trigeminal Lemniscal pathway?

1st - Trigeminal ganglion
2nd - Trigeminal sensory nucleus
3rd - VPM (thalamic)

201

Where is the decussation of the trigeminal lemniscal pathway?

Pons

202

Where do DCML fibers decussate?

Medulla

203

The DCML lower extremity neurons synapse...

nucleus gracilis

204

The DCML upper extremity neurons synapse...

nucleus cuneatus

205

Where are the 1st, 2nd, and 3rd order neurons in the Spinothalamic tract?

1st - DRG
2nd - Substantia gelatinosa of Rexed's lamina II
3rd - VPL (thalamus)

206

Where does the decussation of the Spinothalamic tract occur?

within two levels of entrance into the spinal tract.

at the Anterior White Commisure

207

Where are the 1st, 2nd, and 3rd order neurons in the Trigeminothalamic tract?

1st - Trigeminal ganglion
2nd - spinal nucleus in trigeminal n. in Medulla
3rd - VPM

208

Where does the decussation of the Trigeminothalamic tract occur?

Medulla

209

Both the spinothalamic and trigeminothalamic tracts carry what types of sensing fibers?

pain and thermal A-delta and C afferents

210

Some fibers of what pathway terminate in the brainstem reticular formation and are called the spinoreticular tract fibers?

Lateral Spinothalamic tract

211

The Lemniscal (DCML/trigeminal) and thalamic (lateral spinothalamic and trigeminothalamic) tracts are what type of pathways?

Conscious

212

The DSCT and the SCCT relay what type of information?

Proprioception from spindles and tendon organs to the Cerebellum

213

What are the 1st and 2nd order neurons in the Dorsal Spinocerebellar Tract?

1st - DRG
2nd - Clark's column in nucleus dorsalis

No Cross

214

What class of afferents are found in the DSCT?

Groups Ia and II (muscle spindle)
Ib (tendon organ)

215

Where does the DSCT terminate, and what is its function?

Cerebellum via inferior cerebellar peduncle
Fine coordination posture and limb (LE)

216

Where are the 1st and 2nd order neurons in the spinocuneocerebellar tract?

1st - DRG cervical
2nd - Cuneate nucleus

No decussation

217

What is the nerve class in the Spinocuneocerebellar tract, where do the fibers enter the medulla, and what is their function?

Group Ia and II (muscle spindle) and Ib (tendon organ)
Inf. peduncle
fine coordination of UE mm.

218

What type of info does the VSCT and the RSCT carry?

feedback to cerebellum about descending motor signals

219

Where does the VSCT decussate?

Anterior white commisure

then, after entering the superior peduncle, MOST cross again and end up IPSILATERAL

220

The RSCT (rostral spinocerebellar tract) carries what kind of info?

feedback to cerebellum about descending motor signals to cervical spinal cord.

221

How many synapses are involved in the stretch reflex?

one

stretches Ia and Group II afferents and loops back to the homonymous muscle

222

Does the stretch reflex involve the tendon organs?

NO

Decks in Tim's Cards Class (140):