Ascending tracts to cortex typically have (X) number of neurons.
X = 3
Ascending tracts to cerebellum typically have (X) number of neurons.
X = 2
First order neurons for DCML pathway are in:
DRG
DCML carries which (sensory/motor) signals?
Sensory;
DCML afferent fibers are (myelinated/unmyelinated) and (slow/fast).
(Highly) myelinated; fast
Dorsal column fibers (for DCML path) are arranged into which tracts? Star the most medial tract.
2. Fasciculus Cuneatus
Fasciculus gracilis for (X) SC tract fibers is located at which SC levels?
X = DCML (for lower body, below T6)
All SC levels
Fasciculus cuneatus for (X) SC tract fibers is located at which SC levels?
X = DCML (for upper body, T6 and above)
At T6 and above
Posterior intermediate sulcus found at which SC levels? What does it separate?
T6 and above;
Fasciculi gracilis and cuneatus
(X) and (Y), collectively called dorsal column nuclei, are located in:
X = nucleus gracilis Y = nucleus cuneatus
Caudal medulla
Where do first-order DCML fibers synapse?
Dorsal column nuclei (medulla)
Where does the DCML pathway decussate?
Caudal medulla
Following decussation in (X), the DCML (1/2/3)-order neurons form pathway called (Y).
X = caudal medulla
2-order;
Y = medial lemniscus
Axons in medial lemniscus synapse in (X).
X = VPL nucleus of thalamus
DCML third order neurons travel from (X) to (Y).
X = VPL thalamus Y = somatosensory cortex (parietal lobe)
Spinothalamic tract, part of (X) system, carries which (sensory/motor) signals?
X = anterolateral;
Sensory;
Pain and T
Spinothalamic afferent fibers are (myelinated/unmyelinated) and (slow/fast).
Unmyelinated; Slow
First order neurons for ST pathway are in:
DRG
Lissauer’s tract carries (1/2/3)-order neurons from (X) pathway. Projections travel (up/down/across) to (Y).
1st order;
X = ST
Up and down;
Y = 2-3 SC segments rostral and caudal to DRG
Where is Lissauer’s tract located in SC cross-section?
White matter that caps the dorsal horn
Central process of ST tract synapses within (X), aka Rexed’s lamina (Y).
X = substantia gelatinosa Y = 2
Second order neurons of ST tract are located in (X) area and their dendrites extend to (Y) area.
X =
Y = substantia gelatinosa
Nucleus postero-marginalis is Rexed’s lamina (X).
X = 1
Post-synpatic processes in substantia gelatinosa belong to (1/2/3)-order neurons for (X) tract.
2nd order;
X = ST