Ascending Pathways Flashcards
Differentiate the various ascending pathways
Which tracts are considered conscious relays?
- Dorsal Column Medial Lemniscus
- Spinothalamic
What information is conducted in the spinothalamic tract?
Discriminative pain and temperature, coarse/crude touch
What information is conducted in the dorsal column/medial lemniscus?
discriminative light touch, vibration, conscious proprioception
What information is conducted in the spinocerebellar tract?
- Nonconscious proprioception
- Movement information from descending tracts
What tracts are considered among the divergent pathways?
- spinomesencephalic
- spinoreticular
- spino-emotional
What kind of information is conveyed in the divergent pathways?
slow pain
Where do fibers in the spinomesencephalic tract terminate?
- superior colliculi
- periaqueductal gray
Where do fibers in the spinoreticular tract terminate?
intralaminar nuclei of thalamus (via reticular formation in the brainstem)
Where do fibers in the spino-emotional tract terminate?
- areas of the cerebral cortex involved with emotions, sensory integration, personality, and movement
- basal ganglia
- amygdala
- hypothalamus
What information is conveyed in the spinomesencephalic tract?
slow nociception
What is the effect of slow nociceptive information conducted in the spinomesencephalic tract?
- Via superior colliculi: turning eyes/head to orient toward source of nociceptive stimuli
- Via periaqueductal gray, modulation of incoming nociception
What is the effect of nociceptive information conducted in the spinoreticular tract?
- modulation of arousal, attention, sleep/wake cycle
- alters attention, interferes with sleep
What is the effect of nociceptive information conducted in the spino-emotional tract?
emotional responses to pain
What is a possible result of a lesion in the spinothalamic tract?
- contralateral analgesia
- loss of contralateral temperature sense
What is a possible effect of a lesion in the dorsal column?
- Loss of ipsilateral discriminative light touch
- Loss of ipsilateral conscious proprioception
What information is conveyed in this tract?
Discriminative pain and temperature, and coarse/crude touch information is conveyed in the spinothalamic tract. This anterolateral system also contains the divergent pathways conducting slow pain information.
What information is conveyed in this tract?
The fasciculus gracilis conveys discriminative touch and conscious proprioception information from the lower body/limbs.
What information is conveyed in this tract?
The fasciculus cuneatus conveys discriminative touch and conscious proprioception information from the upper body/limbs.
What information is conveyed in these tracts?
The anterior and posterior spinocerebellar tracts convey movement-related information regarding non-conscious proprioception and descending motor commands.
What pathway is represented by this image?
Spinothalamic
(Anterolateral System)
What pathway is represented by this image?
Dorsal Column Medial Lemniscus
What pathway is represented by this image?
Spinocerebellar (specifically posterior spinocerebellar)
