4-Motor II

Question 1

corticotectal tract starts/ends

Answer 1

og @ occipital lobe (visual association cortex)
terminates @ superior solliculus (midbrain) and oculomotor accessory nuclei (midbrain)

Question 2

tectospinal tract starts/ends

Answer 2

og @ superior colliculus
terminates @ C and T spinal cord levels

aka picks up from corticotectal tract

Question 3

tectospinal tract function

Answer 3

reflex moves of eyes, neck, upper thorax in resp to visual/auditory/vestibular/cutaneous startling stimuli

Question 4

pyramidal cells contribute to what tracts

Answer 4

1. corticonuclear
2. corticorubral
3. corticopontine
4. corticoreticular
5. corticospinal

for conscious voluntary move

Question 5

which tracts do subconscious involuntary control

Answer 5

reticulospinal, vestibulospinal

for background muscular activity to cont modulate muscle tone, posture, balance

Question 6

corticorubral tract start/end

Answer 6

og @ motor cortex
terminate @ red nucleus in midbrain

Question 7

rubrospinal tract start/end

Answer 7

og @ red nucleus
terminate @ cervical spinal cord

picks up corticorubral

Question 8

rubrospinal tract function

Answer 8

excitatory to distal flexor muscles of the UL (hand, digits)

not significant in humans but can allow retain function of distal UL if CST damaged

Question 9

corticoreticular tract start/end

Answer 9

og @ motor cortex
terminate @ brain stem reticular formation nuclei in pons and medulla

Question 10

reticulospinal tracts

RST

Answer 10

1. medial/pontine
2. lateral/medullary

modulate muscle tone and posture maintenance by synapsing with gamma motor neurons

Question 11

medial RST

Answer 11

og @ RF in pons
terminate at all spinal cord levels

excitatory to motor neurons for paravertebral and limb extensors (antigravity muscles) aka for standing

Question 12

lateral RST

Answer 12

og @ RF in medulla
terminates @ all spinal cord levels

inhibitory to motor neurons for paravertebral and limb extensors (antigravity) aka for lying down

Question 13

vestibulospinal tracts

VST

Answer 13

1. lateral VST
2. medial VST

Question 14

lateral VST

Answer 14

og @ lateral vestibular nucleus
terminates @ all levels

excitatory for trunk paravertebral and proximal limb extensors (antigravity) like Medial RST
+elicit automatic reflex resp to modulate tone so when loosing balance tract will adjust to regain upright posture

Question 15

medial VST

Answer 15

og @ medial vestibular nucleus
terminates @ C and upper T levels to inn neck muscle

coordinates head and eye move during gaze

Question 16

functional classification of descending motor pathways

Answer 16

1. ventromedial/anteromedial
2. lateral
3. cortical

Question 17

cortical group

Answer 17

only axons of lateral corticospinal tract (to inn distal limb muscles/hand)

distinct, fractionated moves of digits like playing piano, exquisite motor control

Question 18

lateral group

Answer 18

1. lateral corticospinal tract
2. rubrospinal tract

distal muscles limb (to control digits) esp hand

Question 19

anteromedial group

Answer 19

1. anterior corticospinal
2. medial and lateral vestibulospinal
3. medial and lateral reticulospinal
4. tectospinal

maintain balance for posture via gross moves of axial/trunk and proximal limb

Question 20

poliomyelitis

Answer 20

viral infection of spinal cord LMN so get LMN lesion signs

Question 21

combined systems disease

Answer 21

aka subacute combined degeneration or posterolateral sclerosis
-loss of vibratory, proprioception, touch, discrim
-show UMN lesion signs

from B12 def so abnormal FAs > abnormal myelin
-degen of FG + FC + CST

Question 22

part of spinal cord most susceptible to occlusions

Answer 22

cervical bc no anastomoses with radicular A’s like thoracic, lumbar, and sacral
-only spinal A’s