Ascending Sensory Pathways Flashcards
What are the 1st order neurons for DCML pathway?
Dorsal root ganglia; Axons ascend as Fasciculus gracilis (LE) and Fasciculus Cuneatus (UE)
What does the Dorsal Column Medial Lemniscal Pathway (DCML) carry?
Discriminative tactile sensations from the body
What are the 3rd order nuclei for the DCML pathway?
VPL in Thalamus
What are the 2nd order nuclei for DCML?
Nucleus Gracilis (LE) and Nucleus cuneatus (UE) Axons ascend as Medial Lemniscus
What is the destination for the DCML pathway?
Primary Somatosensory Cortex
Where does the DCML pathway decussate?
2nd order axons cross in the Medulla (fibers called internal Arcuate Fobers that represent sensory decussation for discriminative sense)
What is the DCML innervated by?
by A-beta afferents that (enter the SC in medial regions of Lissauer’s tract )
What does the Trigmenial Lemniscal pathway carry?
Discriminative tactile sensations form the face
What is the 1st order neuron for Trigmenial Lemniscal pathway?
Trigmenial ganglion in pons
What is the 2nd order neuron for Trigmenial Lemniscal pathway?
Trigmenial main sensory nucleus (axons ascend as Trigmenial Lemniscus)
What is the 3rd order neuron for Trigmenial Lemniscal pathway?
VPM in thalamus
What is the destination for Trigmenial Lemniscal pathway?
Primary Somatosensory cortex
What is the decussation for Trigmenial Lemniscal pathway?
2nd order axons cross in the PONS
What is the innervation for Trigmenial Lemniscal pathway?
A-beta afferents
What does the Spinothalamic Tract carry?
Pain, thermal sense, and crude touch from body
What is the 1st order neuron for the (lateral) Spinothalamic tract?
DRG (A-delta and C afferents)
What is the 2nd order neuron for the (lateral) Spinothalamic tract?
Substantia gelantinosa of Rexed’s lamina II
What is the 3rd order neuron for the (lateral) Spinothalamic tract?
VPL in Thalamus
What is the destination for the (lateral) Spinothalamic tract?
Primary Somatosensory cortex
What is the decussation for the (lateral) Spinothalamic tract?
2nd order sensory axons in SC (anterior white commisure) w/in 1-2 levels of entering the SC
What do some fibers in the (lateral) Spinothalamic tract terminate as?
Brainstem reticular formation and are called spinoreticular tract fibers
What does the Trigeminothalmic tract carry?
carries pain and thermal sense from free nerve endings and heat and cold receptors in the face
What is the 1st order neuron for the Trigeminothalmic tract?
Trigeminal ganglion (A-delta and C afferens)