Spinal Tracts Flashcards
What is another name for the Dorsal Column Tract?
Medial Leminiscus
What is the DCML pathway responsible for?
- Discriminate touch
- Pressure, stretch, and vibrations
- proprioceptions
What kind of tract is the DCML?
Ascending Tract
Where is the decussation of the DCML pathway?
Medulla Oblongata
How many neurons are in the DCML pathway?
3 neurons
Where does the 1st order neuron of the DCML tract enter the spinal cord?
Dorsal part of the spinal cord
Where does the 1st order neuron synapse with the 2nd order neuron in the DCML Tract?
Medulla Oblongata
It then decussates
Where does the 2nd order neuron synapse in the DCML Tract?
The VPL in the thalamus
Where does the 3rd order neuron synapse in the DCML Tract?
Areas 3,1,2 in the Cortex
The fasiculus gracilis is responsible for information from where?
Lower Limbs
The fasiculus cuneus is responsible for information from where?
Upper Limbs
If there is a lesion before the Medulla in the DCML Tract, will it affect ipsilateral or contralateral?
Ipsilateral
If there is a lesion after the Medulla in the DCML Tract, will it affect ipsilateral or contralateral?
Contralateral
What is the pathway for the DCML after it enters the brain?
It travels to the posterior 1/3 of the internal capsule, goes to the corona radiata, and goes to S1 & 2
Is the Anterolateral Spinothalamic Tract ascending or descending?
Ascending
Which fibers are faster: A-delta fibers or C fibers?
A-delta
What kind of sensations/pain do A-delta fibers respond to?
- Extreme/cold temps
- mechanical stress (smashing your hand)
- Pin pricks
What kind of sensations/pain do C fibers respond to?
-Dull pain from chemical stress
What is another name for the Anterolateral Spinothalamic Tract?
Spinal Leminiscus
What kind of sensation does the Anterolateral Spinothalamic Tract carry?
Pain and Temperature
Where do A-delta fibers synapse in the AST?
Rexxed lamina 1 and 5
What is the neurotransmitter that is released by A-delta fibers in the AST?
Glutamate
Where do C fibers synapse in the AST?
Rexxed lamina 2 and 3
What is the neurotransmitter that is released by C-fibers in the AST?
Substance P
Merkel’s discs, free nerve endings, peritrichial nerves for crude touch and pressure are associated with which tract?
Anterolateral Spinothalamic Tract-Spinal Leminiscus
Where does a lesion of the Anterolateral Spinothalamic Tract affect?
Lesion affects at SC segments
-This is called the Tract of Lassaeur
In the Anterolateral Spinothalamic Tract, what happens to the C fibers?
Most C fibers (85%) terminate at the reticular formation which goes to the intralaminar nuclei
Where is the deccusation in the Anterolateral Spinothalamic Tract?
In the Spinal Cord usually 1 or 2 segments below