Tracts

Question 1

What is the corticospinal tract responsible for?

Answer 1

Motor control

Question 2

What is the dorsal column pathway responsible for?

Answer 2

Vibration, proprioception, and light touch.

Question 3

What is the spinothalamic tract responsible for?

Answer 3

Pain, temperature, and crude touch.

Question 4

Which pathway is being described here?

1. Low threshold mechanoreceptors.
2. Large diameter, A-alpha fibres (thick myelination)
3. High conduction velocity

Answer 4

Dorsal column pathway

Question 5

What are the best bedside tests for the dorsal column pathway?

Answer 5

1. Proprioception (bend distal phalanx)

2. Vibrating tuning fork (128Hz)

Question 6

Which pathway is being described here?

1. Nociceptors and thermoreceptors
2. A-delta (thin axons, light myelination), and C fibres (no myelin)
3. Slower conduction velocity

Answer 6

Spinothalamic tract

Question 7

What are the best bedside tests for the spinothalamic tract?

Answer 7

1. Pain and temperature

2. Pinprick using neurotip

Question 8

What are the two sections of the dorsal column pathway and which areas of the body are they responsible for?

Answer 8

1. Cuneate fasciculus - above T6

2. Gracile fasciculus - below T6

Question 9

Where do each of these ascending pathways decussate in the spinal cord?

1. Dorsal columns (cuneate and gracile)
2. Spinocerebellar
3. Lateral spinothalamic
4. Anterior spinothalamic

Answer 9

1. Brainstem lower medulla - medial lemniscus
2. Does not decussate
3. Spinal cord - at level of entry across anterior white commissure
4. Spinal cord - 2-15 segments above point of entry

Question 10

Where do each of these descending pathways decussate in the spinal cord?

1. Lateral corticospinal
2. Anterior corticospinal
3. Rubrospinal
4. Vestibulospinal

Answer 10

1. Medullary pyramids
2. Does not decussate
3. Midbrain
4. Does not decussate