Ascending + Descending Pathways

Question 1

What signals are carried in the dorsal column medial meniscal pathway?

Answer 1

Fine touch, vibration, proprioception

Question 2

What are the 2 parts of the DCML pathway and what is its route?

Answer 2

Fasciculus cuneatus: upper limb (lateral)
Fasciculus gracilis: lower limb (medial)

1st order: skin - medulla
2nd order: medulla - thalamus (decussates in the medulla)
3rd order: thalamus - cerebral cortex

Question 3

Where do the DCML and STT pathways decussate?

Answer 3

DCML = medulla
STT = spinal cord

Question 4

What signals are carried in the 2 parts of the spinal thalamic tract

Answer 4

Anterior: crude touch + pressure
Lateral: pain + temp

Question 5

What is the route of the STT?

Answer 5

1st order: skin - spinal cord
2nd order: spinal cord - thalamus
3rd order: thalamus - cerebral cortex

Question 6

What is the function of the spinocerebellar tracts?

Answer 6

Carry unconscious proprioceptive info (coordinate movement)

Question 7

What side does the spinocerebellar tract reach the brain?

Answer 7

Ipsilateral (doesn’t cross over)

Question 8

What is the difference between pyramidal and extrapyramidal tracts?

Answer 8

Pyramidal: voluntary motor movement
Extrapyramidal: involuntary + autonomic motor control

Question 9

What is the difference between upper and lower motor neurones?

Answer 9

UMN: cause motor movement (disorder = spasticity)
LMN: prevent excessive motor movement (disorder = flaccidity)

Question 10

What are the 2 pyramidal tracts and what do they supply?

Answer 10

Corticospinal: supplies body
Corticobulbar: supplies face

Question 11

What are the extrapyramidal tracts and which ones decussate?

Answer 11

Reticulospinal, vestibulospinal, rubrospinal, tectospinal

Decussate: rubrospinal, tectospinal

Question 12

What is the function of the vestibulospinal tract and on which side of the brain do signals originate?

Answer 12

Controls balance + posture (‘anti-gravity’ flexors or arm + extensors of leg)
Ipsilateral

Question 13

What is the function of the 2 parts of the reticulospinal tract and on which side of the brain do signals originate?

Answer 13

Medial: facilitates voluntary movement, increases tone
Lateral: inhibits voluntary movement, decreases tone
Ipsilateral

Question 14

What is the function of the rubrospinal tract and on which side of the brain do signals originate?

Answer 14

Controls fine hand movements

Contralateral

Question 15

What is the function of the tectospinal tract and on which side of the brain do signals originate?

Answer 15

Coordinates movement from visual stimuli (from superior colliculus of midbrain)
Contralateral