Spinal tracts Flashcards
What do UMNs do?
Talk to LMNs
What do LMNs do?
Talk to skeletal muscles
Where do UMNs originate?
In grey matter of cerebral cortex & brainstem
Where do LMNs originate?
Have their soma’s in brainstem or the spinal cord
What are the 5 features of a UMN disorder?
- Hypertonia (stiffness)
- Hyperreflexia (brisk reflexes)
- +ve Babinski signs (abnormal extensor plantar response)
- Spactic weakness
- Little muscle atrophy
What are the 5 features of a LMN disorder?
- Hypotonia
- Hyporeflexia
- Fasciculations (twitching under the skin)
- Flaccid weakness (floppy)
- Muscle atrophy
What information does the DCML (dorsal column-medial lemniscus) carry? (5)
Proprioception Discriminative (two-point) touch Fine touch Pressure Vibration
Where does the DCML start?
Sensory organ
Where does the DCML end?
Somatosensory cortex
Where does the DCML decussate?
Medulla
How does the DCML from the lower body (T6 and below) travel through the medulla?
Fasciculus gracilis (MEDIAL) Remember: Ground --> Gracilis
How does the DCML from the upper body (T6 and above) travel through the medulla?
Fasciculus cuneatus (LATERAL)
What information does the STT (spinothalamic tract) carry? (2)
Lateral: pain & temperature
Where does the STT start? (2)
Nocioceptors
Thermoreceptors
Where does the STT end?
Thalamus (pain reaches consciousness here)
Where does the STT decussate?
At level of entry of spinal cord/ up to 2 levels above
What information does the SCT (spinocerebellar tract) carry? (2)
Balance
Coordination
Where does the SCT start? (2)
Golgi organs
Muscle spindles
Where does the SCT end?
Cerebellum
Where does the SCT decussate?
Dorsal DON’T
Ventral DOUBLE CROSS
What information does the lateral CST (corticospinal tract) carry?
Motor (to limbs)
Where does the lateral CST start?
Motor cortex
Where does the lateral CST end?
motor neurons/ NMJ
Where does the lateral CST decussate?
Medulla
What information does the anterior CST carry?
Motor (to head & trunk)
Where does the anterior CST start?
Motor cortex
Where does the anterior CST end?
Motor neurons/ NMJ
Where does the anteior CST decussate?
At level of exit on spinal cord
What information does the RST (rubrospinal tract) carry?
Rudimentary motor function
Where does the RST start?
Red nucleus (midbrain)
Where does the RST end?
Motor neurons/ NMJ
Where does the RST decussate?
Midbrain
What information does the TST (tectospinal tract) carry?
Reflex head/eye responses to visual/auditory stimuli
Wherw does the TST start?
Tectum (midbrain) [visual: superior colliculi] [auditory: inferior colliculi]
Where does the TST end?
Motor neurons/ NMJ
Where does the TST decussate?
Midbrain
What ipsilateral deficit will a person with Brown-Sequard syndrome present with?
Below the lesion/injury:
Loss of motor function
Loss of pressure, discriminative two-point touch and proprioception
What contralateral deficit will a person with Brown-Sequard syndrome present with?
Below the lesion/injury:
Loss of pain + temperature
