Lecture 10- Spinal Cord 2 Flashcards
What are the 3 types of intra spinal/propriospinal fibers?
Comissural- Ant. White Commissure
Interspinal- Lissauer’s Tract
Intraspinal- Fasiculis Proprius
How do degenerating pathways present on a myelin stain?
Pale regions
What type of information is carried in Lissauer’s tract?
Pain and temperature
What is another name for an alpha motor neurons?
Anterior horn neurons
What is the difference between the Fasciculus cuneatus and Fasciculus gracilis?
Cuneatus- above T6- nucleus cuneatus to VPL
Gracilis- below T6- nucleus gracilis to VPL
Which sensory pathway is found in the anterior/ventral spinal cord?
Anterolateral system
List the 5 pathways that are a part of the anterolateral system.
- Neospinalthalamic tract
- Paleospinalthalamic tract
- Anterior Spinothalamic tract
- Spinomesencephalic tract
- Spinoreticular tract
What is the function of the dorsal column/medial lemniscus system?
Fine touch
Pressure
Vibration
Position
Where do fibers cross in the dorsal column system?
Cross at medulla to form medial lemniscus
Where is the VPL located?
Ventroposterolateral nucleus of thalamus
What are the functions of the 5 pathways of the anterolateral system?
4 pain
1 crude touch
Where do pain pathways cross the midline?
At spinal level through the anterior white Commissure
What is the function of the Neospinalthalamic tract?
fast Pain and temp
What tract carries crude touch information?
Anterior Spinothalamic tract
What does the dorsal spinocerebellar become above C8?
Cuneocerebellar tract
What is the ventral spinocerebellar tract know as above C8?
Rostral spinocerebellar
Where are the second order sensory neurons for the dorsal spinocerebellar tract below C8?
Nucleus Dorsalis of Clarke
Where are the second order sensory neuron for the cuneocerebellar tract (above C8)?
External cuneate nucleus (caudal medulla)
How does information from the dorsal and cuneocerebellar tracts cross into the cerebellum?
Via the inferior cerebellar peduncle
How does information from the ventral and rostral cerebellar tracts enter the cerebellum?
Via the superior cerebellar peduncle
Which of the ALS pathway can project bilaterally?
Anterior Spinothalamic tract
Which of the spinocerebellar tracts crosses twice?
Ventral spinocerebellar tract
Where are the second order neurons located for the ventral and rostral spinocerebellar tracts?
Spinal border cells (lamina V-VII)
What is the function of the ventral/rostral spinocerebellar tract?
Info about entire limbs-muscle sense
What is the function of the dorsal and cuneocerebellar tracts?
Individual muscle sense
What is tabis dorsalis?
Cause by sphyllis-death of cells in dorsal column-loss of sensation in affected area
Where do the lateral and anterior corticospinal tracts originate?
Motor and pre motor cortex in pre-central gyrus of the frontal lobe
Where is the pre-motor cortex? What pathways originate here?
Frontal lobe
Origination of the lateral and anterior corticospinal tracts
Where do the fibers of the lateral corticospinal tract decussate?
Pyramidal decussation in the caudal medulla
Where do they anterior corticospinal tract fibers decussate?
They cross at their target segment rather than in pyramids
Where are the 3rd neurons of the paleospinothalmic (part of ALS) located? Where do they project?
intralaminar nucleus of the thalamus project to the cingulate cortex
Which pathway terminates in the cinguate cortex?
Paleospinothalamic tract (part of ALS)- Dull pain
How are the Neospinothalamic and Paleospinothalamic pathways different?
Neo- sharp, well localized pain, VPL-> somatosensory cortex
Paleo- dull, diffuse pain, intralaminar nucleus–> cingulate cortex
What is polio?
a neurodegenerative disease of the anterior horn neurons
What is Brown-Sequard syndrome? What does it result in?
Complete hemisection of spinal cord
-Results in loss of sensation on affected side and loss of motor ability on opposite side
Where does the rubrospinal tract originate?
Red Nucleus of the midbrain
Where do the fibers of the rubrospinal tract cross?
VTD- Ventral Tegmental Decussation in midbrain
Which muscles does the rubrospinal tract preferentially affect?
muscles of distal flexor muscles
What is the function of the raphespinal tract?
modulate pain in the spinal cord
What is the tectospinal tract involved in?
moves head in response to visa stimuli
Where does the tectospinal tract originate?
superior colliculus of the midbrain
Which tract mediates posture and balance by acting on distal extensor muscles?
Lateral Vestibulospinal Tract
Which spinal tract is involved in maintaining head position in response to vestibular information?
Medial Vestibulospinal Tract
What is the Medial Vestibulospinal tract known as in the brainstem?
MLF- Median Longitudinal Fasiculus
Where does the Medial Vestibulospinal Tract project to?
interneurons in lamina VIII and IX at the CERVICAL LEVELS
