Ascending/Descending Pathways

Question 1

describe the corticospinal pathway

Answer 1

1. primary motor cortex
2. corona radiata
3. internal capsule
4. medullary pyramids
5. decussates in medullary pyramids (lateral) or anterior white commissure (anterior)
6. ventral horn

Question 2

describe the corticobulbar pathway

Answer 2

1. primary motor cortex
2. internal capsule
3. brainstem
4. medullary pyramids
5. motor nuclei of cranial nerves
6. LMN

Question 3

describe the spinothalamic pathway

Answer 3

1. sensory receptor
2. spinal cord
3. synapses in dorsal horn
4. decussates
5. spinal cord
6. anterior/lateral
7. synapses in thalamus
8. internal capsule
9. somatosensory cortex

Question 4

describe the DCML pathway

Answer 4

1. sensory receptor
2. dorsal root ganglion
3. dorsal root
4. lateral/medial
5. synapses in medulla
6. medial lemniscus
7. synapses in thalamus
8. internal capsule
9. somatosensory cortex

Question 5

what is the function of the spinothalamic tract?

Answer 5

lateral - pain & temperature

anterior - crude touch & pressure

Question 6

what is the function of the DCML?

Answer 6

• proprioception
• 2-point discrimination
• fine touch
• vibration

Question 7

does the spinothalamic tract decussate?

Answer 7

yes

- dorsal horn

Question 8

does the DCML tract decussate?

Answer 8

yes

- medulla

Question 9

what is the function of the spinocerebellar tracts?

Answer 9

unconscious proprioception

Question 10

do the spinocerebellar tracts decussate?

Answer 10

no

anterior does but twice

Question 11

what is the function of the pyramidal tracts?

Answer 11

conscious muscle control

Question 12

what is the function of extrapyramidal tracts?

Answer 12

unconscious muscle control

Question 13

name 3 ascending motor tracts

Answer 13

• spinothalamic
• DCML
• spinocerebellar

Question 14

what are the 2 types of descending motor pathways?

Answer 14

• pyramidal

- extrapyramidal

Question 15

which muscles does the corticobulbar tract supply?

Answer 15

• head

- neck

Question 16

where do the extrapyramidal tracts orginate?

Answer 16

brainstem

Question 17

what is the function of the vestibulospinal tract?

Answer 17

• balance

- posture

Question 18

what is the function of the reticulospinal tract?

Answer 18

medial:
- facilitates voluntary muscle movements 
- increases muscle tone
lateral:
- inhibits voluntary muscle movements
- decreases muscle tone

Question 19

what is the function of the rubrospinal tract?

Answer 19

fine control of head movement

Question 20

what is the function of the tectospinal tract?

Answer 20

movement of the head in relation to visual stimuli

Question 21

which extrapyramidal tracts decussate?

Answer 21

• rubrospinal

- tectospinal

Question 22

name 2 pyramidal tracts

Answer 22

• corticospinal

- corticobulbar

Question 23

are the pyramidal tracts ascending or descending?

Answer 23

descending

Question 24

name 4 extrapyramidal tracts

Answer 24

• vestibulospinal
• recticulospinal
• rubrospinal
• tectospinal