Neuroscience Week 3: Ascending Spinal Tracts Flashcards
Key Ascending Spinal Cord Pathways
- Posterior column
- anterolateral system (spinothalamic tract)
- Spinocerebellar
Posterior Column fiber size
Large sensory fibers
Posterior Column Function
Proprioceptive sensation
- Vibration
- Two-point discrimination
- joint position information
Posterior Column Course
Ipsilateral
Posterior Column Divisions
At T6 Cuneate - (Arms)
Gracile - (Legs)
Anterolateral system (spinothalamic tract) Fiber size
small fibers
Anterolateral system (spinothalamic tract) Function
- Pain
- temperature
- itch
Anterolateral system (spinothalamic tract) Course
- doesn’t just synapse in the thalamus but the hypothalamus and brainstem which is why it is referred to the anterolateral system
- contralateral ascension of the spinal cord
Anterolateral system inner and outer
Inner - Arms
Outer - Legs
Cervical Syringomyelia
Syrinx affects inner arm fibers first before leg fibers
Anterolateral system lateral and anterior
Lateral - pain/temperature
Anterior - Tactile/pressure
Spinocerebellar Tract Fiber Size
Large sensory fibers
Spinocerebellar Tract Function
joint proprioception to cerebellum for coordination
Spinocerebellar Tract Course
What type of neurons are spinal sensory nerves?
Pseudounipolar because it passes peripherally to join the motor root and centrally to join the spinal cord
Spinocerebellar tracts
Large sensory fibers
Spinocerebellar tracts Function
Joint proprioception for coordination
Cell bodies for spinal sensory fibers lie in
Dorsal root ganglia
spinal sensory axons are?
Pseudounipolar
Lissauer Tract
The entry zone for the anterolateral system fibers
Ventral Commissure
site where anterolateral system fibers decussate within the spinal cord
Posterior median septum
separates the bilateral sides of the posterior column
Posterior Intermediate Septum
separates ipsilateral fasciculi
