N34

Question 1

Corticofugal pathways

Answer 1

begin in layer V of cerebral cortices

Question 2

Pyramidal system

Answer 2

voluntary movement; corticospinal and corticonuclear tracts; bineuronal; fast uninterrupted, non-modulated

Question 3

Pyramidal system function

Answer 3

realization of movement; contralateral side (some bilateral)

Question 4

Corticospinal tract

Answer 4

Layer V of MI, PMC, SMA, SI, PMA –> corona radiata posterior limb of IC –> middle crus cerebri –> pyramid

Question 5

Lateral corticospinal tract (LCST) decussates

Answer 5

pyramidal decussation –> lateral funiculus (85%) –> activation of distal musculature neurons

Question 6

Anterior corticospinal tract (ACST) decussates

Answer 6

ventral funiculus –> decussate at anterior white commissure at level of termination (15%) –> activation of axial musculature

Question 7

Corticospinal tract receives input from?

Answer 7

MI, SI, PMA, PMC, and SMA

Question 8

Corticonuclear tract receives input from?

Answer 8

MI, SI, PMA, PMC, and SMA

Question 9

Corticonuclear tract synapses on?

Answer 9

CN nuclei 3-7, 9-12

Question 10

Corticonuclear tract path

Answer 10

posterior limb of IC –> middle crus cerebri –> fibers terminate has they descend through midbrain (3,4) pons (5,6,7) and medulla (9,10,11,12)

Question 11

Corticonuclear tract synapse

Answer 11

BILATERALLY except CN7 and CN12

Question 12

Rubrospinal tract path

Answer 12

Red nucleus –> lateral funiculus –> LMN

Question 13

Rubrospinal tract decussates

Answer 13

midbrain where is originates

Question 14

Red nucleus receives input from

Answer 14

cortex (corticorubro fibers) ipsilaterally

Question 15

Rubrospinal tract innervates

Answer 15

FLEXOR musculature (UE)

Question 16

Lesion to the Rubrospinal tract only

Answer 16

can still walk but unable to do fine movements

Question 17

Lateral Vestibulospinal tract path

Answer 17

lateral vestibular nuclei–> ventral funiculus –> ventral horn (bilateral)

Question 18

Lateral Vestibulospinal tract (LVST) function

Answer 18

postural; primarily extensors of the LL

Question 19

Medial Vestibulospinal tract path

Answer 19

medial vestibular nuclei –> MLF to cervical levels–> axial EXTENSOR musculature

Question 20

Medial Vestibulospinal tract (MVST) function

Answer 20

posture and head movements

Question 21

Lateral reticulospinal tract path

Answer 21

medullary reticular formation –> bilateraly in lateral funiculus –> EXTENSORS

Question 22

Medial reticulospinal tract path

Answer 22

pontine reticular formation –> ipsilateral through ventral funiculus –> EXTENSORS

Question 23

Tectospinal Tract path

Answer 23

Superior Colliculus –> decussates in midbrain –> reflex control of head and neck and eyes

Question 24

MRST receives input from

Answer 24

ascending pathways

Question 25

LRST receives input from

Answer 25

cerebral cortex

Question 26

Which pathways carry info form the cerebral cortex?

Answer 26

RST, VST, LRST, MRST, TST, CST

Question 27

extrapyramidal systems

Answer 27

control of a movement and its modulation (INVOLUNTARY) adjustment and synchronization

Question 28

Extrapyramidal descendign pathways

Answer 28

are multisynaptic and enter reverberating circuits for extensive modulation of complex movement