Spinal Cord and PNS: Sensory pathways Flashcards
What are the 3 ascending pathways?
1) SPINOCEREBELLAR PATHWAY
2) POSTERIOR COLUMN PATHWAY
3) SPINOTHALAMIC PATHWAY
What are some characteristics of the SPINOCEREBELLAR PATHWAY?
- Proprioception from muscles, joints, tendons
- Ends at CEREBELLUM
- Not aware of this stimulus
- Info used to fine tune movement
What are some characteristics of POSTERIOR COLUMN PATHWAY?
- Fine touch, pressure, vibration
- Cross over in MEDULLA OBLONGATA
- Synapse in THALAMUS
- Ends at SOMATOSENSORY CORTEX
- Aware of this stimulus
What are some characteristics of SPINOTHALAMIC PATHWAY?
- Crude touch, pain, itch, temp.
- Cross over in SPINAL CORD
- Synapse in THALAMUS
- Ends at SOMATOSENSORY CORTEX
- Aware of this stimulus
What are some similarities between all 3 ascending pathways?
- All pass through the DORSAL ROOT GANGLION and DORSAL ROOT
- All synapse in POSTERIOR GREY HORN
- All go through WHITE COLUMNS (myelinated AXONS)
- Multiple NEURONS in pathway
Which pathway would a touch on the right arm take?
POSTERIOR COLUMN PATHWAY
Where can SENSORY NEURONS enter the SPINAL CORD?
1) DORSAL RAMUS
2) VENTRAL RAMUS
3) SYMPATHETIC NERVE
Where are all the CELL BODIES of the SENSORY NEURONS?
In the DORSAL ROOT GANGLION
Don’t fuck with the Dorsal Root Gang >:)
Where do the AXONS pass through on their way to the SPINAL CORD?
The DORSAL ROOT
Where do all the SENSORY NEURONS synapse when they are entering the SPINAL CORD?
At the POSTERIOR GREY HORN
Through which 3 columns can SENSORY NEURONS ascend to the BRAIN?
1) POSTERIOR WHITE COLUMN
2) LATERAL WHITE COLUMN
3) ANTERIOR WHITE COLUMN
Describe, in full, the route a SENSORY NEURON would take to enter the BRAIN
- Arrive at either DORSAL RAMUS, VENTRAL RAMUS, or SYMPATHETIC NERVE
- Pass through DORSAL ROUTE GANGLION
- Pass through DORSAL ROOT
- Pass through POSTERIOR GREY HORN
- Ascend to the BRAIN via either the POSTERIOR WHITE COLUMN, LATERAL WHITE COLUMN, or ANTERIOR WHITE COLUMN
