Ascending/Descending Spinal Tracts

Question 1

Sensory homunculus

Answer 1

Medial - lower limb
Dorsolateral - upper limb
Lateral - face

Question 2

DCML

Answer 2

Vibratory, fine touch, proprioception

Dorsal column medial lemniscus pathway

Fasculus gracilis and cuneatus

Question 3

Cervical vs lumbar levels of DCML

Answer 3

Columnar shape in cervical

Question 4

Fasciculus gracilis and cuneatus

Answer 4

Gracilis is at all levels

Cuneatus is only at cervical and is more lateral

Question 5

1st order
2nd order
3rd order neurons of DCML

Answer 5

1st - located in spinal ganglia of spinal cord between (T7-Co1 for gracilis and C1-T6 for cuneatus) and project into ipsilateral nucleus gracilis of cauda medualla

Second - project to contralateral ventral posterior lateral nucleus (VPL) of the thalamus…crossing fibers are arcuate fibers/medial lemniscus

3rd - go to postcentral gyrus of parietal lobe via internal capsule

Question 6

Posterior cord syndrome just the gracilis

Answer 6

If injury to the gracilis, then get ipsilateral loss of vibration, dsicrimitive touch, and proprioception

Question 7

Posterior cord syndrome both cunaeuts and gracilis

Answer 7

Ipsilateral loss of vibratory, fine touch, and proprioception to both upper and lower body

Question 8

Spinothalamic pathway and organzation

Answer 8

Nociceptive and temp for all of body but head

All spinal cord levels

Made of lateral and anterior tract

More caudal is morelateral

Question 9

1st
2nd
3rd order
Spinothalamic pathway

Answer 9

1st - central processes in the dorsal root entry zone and may synapse in lamina 1,2,or 5

2nd - neurons from lamina 1 or 5 cross contralateral by anterior white commisure and terminate on VPL

3rd - from VPL to the primary sensory cortex

Question 10

Anterior spinothalamic pathway

Answer 10

Concerned with conveying crude touch

Question 11

Spinothalamic tracts also communicate with

Answer 11

REticular formation

Question 12

Brown-Sequard ysndrome only sensory

Answer 12

Lesion of the entire right side of the spinal cord

At the lesion - total loss of sensory on ipsilateral

Ipsilateral loss of vibration, proprioception, and fine touch beow

Contralateral loss of pain and temp below (1 or 2 below)

Question 13

Central cord syndrome

Answer 13

Cyst or caivty in spinal cord creates a lesion of the anterior commissure expanding 1-2 segments resulting in bilateral loss of pian and temp at level of lesion

Question 14

Posterior spinocerebellar pathway

Answer 14

Conveys proprioception and fine touch to lower limb and trunk

Question 15

1st

2nd neurons for posterior spinocerebellar pathway

Answer 15

First - terminate in dorsal nucleus of clarke

2nd - remain ipsilateral and enter cerebellum by way of inferior cerebellar peduncle (medulla) and terminate in cerebellar cortex

Question 16

Anterior spinocerebellar trat

Answer 16

For whole limnb movements

Question 17

Anterior spinocerebellar 1st and 2nd

Answer 17

1st - central enter between T12 and S2 and terminate on spinal border neurons of ventral horn

2nd - cross at white commissure and enterr via the superior cerebellar peduncle

Question 18

Cuenocerebellar pathway

Answer 18

Equivalent to the posterior spinocerebellar tract (for upper limb and superior trunk)

Question 19

Cuenocerebelar tract 1st and 2nd

Answer 19

1st - ascend in the fasciculus cuneatus and terminate in accessory cuneate nucleus

2nd - ascend through inferior cerebellar peduncle to ipsilateral cerebellar cortex

Question 20

Lower motor neuron lesion signs

Answer 20

Ipsilateral to lesion

Flaccid paralysis
Hyporeflexia
Muscle atrophy
Muscle fasciculation early in course of the lesion

Question 21

Corticospinal tract names

Answer 21

Subcortical - corona radiata and internal cpasule
Midbrain - cerebral peduncles
Pons - corticospinal fibers
Medulla - pyramids
Spinal cord - lateral or medial corticospianl tract

Question 22

Corticospinal path crossiover

Answer 22

Through pyramidal decussation in the caudal medulla

Question 23

Lateral corticospinal tract

Answer 23

Descends in posterior portion of lateral funiculus and terminates on interneurons and somatomotor neurons in the ventral horn of the spinal cord

Question 24

Anterior corticospinal tract

Answer 24

These terminate on the medial portion of the anteriro horn (trunk muscles)

Question 25

Corticospianl organization

Answer 25

Cervical spinal cord fibers medial while sacral are more lateral

Question 26

Upper motor neuron lesions

Answer 26

Little atrophy Spastic paralysis Hyper reflexia Extensor plantar sign

Question 27

Brown-sequard syndrome motor

Answer 27

Damage to anterior grey matter causes ipsilateral LMN signs AT the level Damage to lateral corticospinal tracts causes ipsilateral UMN signs BELOW the level of the lesion

Question 28

Lateral vestibulospianl tract

Answer 28

Extensory muscles associated with axial region and lower limb for positioning

Question 29

Medial vestibulospinal tract

Answer 29

Cervical and upper thoracic levels of the spinal cord Helps control head positioning

Question 30

Tectospinal tract

Answer 30

Moves head and neck in position to visualize an object

Question 31

Reticulospinal tracts

Answer 31

Activate an extensor reflex

Question 32

Rubrospinal tract

Answer 32

Red nucleus in the rostral midbrain...faciliates flexor muscles and inhibits extensor muscles

Question 33

Postures

Answer 33

Decorticate - patient is stiff iwth arms bent toward the body...above the red nucleus lesion Decerebrate posture - lesion at or below the level of the red nucleus meaning rubrospianl tract is pborken