Ascending Pathways

Question 1

What are the 2 main pathways to conscious level?

Answer 1

dorsal column pathway and anterolateral pathway

Question 2

What does the dorsal column pathway do?

Answer 2

discriminative touch, pressure, vibratory sense, conscious proprioception

Question 3

What does the anterolateral pathway do?

Answer 3

nociception, temperature, crude touch

Question 4

Describe the pathways to conscious level (both anterolateral and dorsal column)

Answer 4

see notes

Question 5

What are the different fibre types, their conduction velocity and receptor?

Answer 5

III + IV= slowest and smallest diameter fibres (for nociception and temperature- anterolateral pathway)
In dorsal column pathway= specialised receptors that are more complex with larger nerves:
- II: skin receptors
- Ib: golgi tendon + ruffini endings
- Ia: muscle spindles

Question 6

What is the lissauer’s tract?

Answer 6

area between the tip of the dorsal horn and the surface

Question 7

What are the anterolateral pathways?

Answer 7

Spinothalamic (to VPL) (spine to thalamus): Conscious awareness of nociception (brain) accurately locating source of the pain
Spinomesencephalic (to PAG): Descending pain modulation
Spinoreticular (to RF) RF is in tegmentum: Arousal/attention also motor output
Spinobulbar (brainstem nuclei) and colliculi: Adaptive responses
Spinohypothalamic (to hypothalamus): Autonomic responses to nociception

Question 8

What are the spinocerebellar tracts and what areas do they relate to?

Answer 8

posterior spinocerebellar tract (trunks + LL); cuneocerebellar tract (UL equivalent of posterior spinocerebellar); anterior spinocerebellar tract (LL); rostral spinocerebellar tract (UL equivalent of anterior spinocerebellar tract)

Question 9

What are the trigeminothalamic pathway equivalent to the ascending pathways?

Answer 9

anterolateral (3) = spinal trigeminothalamic (3)
dorsal column (3) = chief sensory (3)
spinocerebellar (2) = mesencephalic (2)