Session 3 - Spinal Afferent fibres Flashcards
Name five tracts of the spinal cord
Dorsal Column Lateral spinothalamic Anterior spinothalamic Anterior spinocerebellar Posterior spinocerebellar
What is the function of the dorsal column
Fine touch, vibration
How many order neurones are there in the dorsal column tract?
Three
What do first order neurones of the dorsal column have their cell body in?
Dorsal root ganglion
Where do 2nd order neurone cell bodies of the dorsal column reside?
Cuneate (upper limb)/Gracile nucleus (lower limb)
Where are the cell bodies of the third order neurones of the dorsal column?
Thalamus
Where does the dorsal column decussate?
Medula
Where does the dorsal column decussate?
Somatosensory cortex
What is the function of the lateral spinothalamic tract?
Pain
Temperature
Where is cell body of 1st order neurone of lateral spinothalamic tract
dorsal root ganglion
Where is cell body of 2nd order neurone in lateral spinothalamic tract
Dorsal horn
Where is cell body of third order neurone cell body of lateral spinothalamic tract
Thalamus
Where does decussation of lateral spinothalamic tract take place
spinal cord
Where does termination of lateral spinothalamic tract take place
Somatosensory cortex
What is function of anterior spinothalamic tract?
Crude touch
Pressure
1st order neurone cell body anterior spinothalamic tract?
Dorsal root ganglion
2nd order neurone cell body anterior spinothalamic tract?
Dorsal horn
3rd order neurone cell body anterior spinothalamic tract?
thalamus
Decussation of anterior spinothalamic tract?
Spinal cord
Termination of anterior spinothalamic tract?
Somatosensory cortex
What is function of anterior spinocerebellar tract?
Unconscious proprioception
1st order neuron cell body anterior spinocerebellar tract?
Dorsal root ganglion
2nd order neuron cell body anterior spinocerebellar tract?
spinal grey matter
3rd order neurone cell body of anterior spinocerebellar tract?
None
Where is decussation of anterior spinocerebellar tract?
Spinal cord (re-crosses at superior cerebellar peduncle)
Where is termination of anterior spinocerebellar tract??
Cerebellum
Function of posterior spinocerebellar tract#;
Unconscious proprioception
1st order neurone cell body anterior spinocerebellar tract?
Dorsal root ganglion
2nd order neurone cell body
Cuneate nucleus
Termination of anterior spinocerebellar tract?
Cerebellum
What does vit b12 deficiency cause?
o Subacute Combined degeneration of dorsal column
Comes about secondary to alcohol addiction
Will have a o Stick and Stamp pattern of gait due to Sensory Ataxia – Loss of sensory input necessary for motor feedback
What is syringomyelia?
o Repeated trauma to the neck (e.g. rugby) causes formation of Elongated Cavity or Syrinx around the Central Canal of the spinal cord.
o As it expands it compresses fibres, such as those of the spinothalamic tract which cross segmentally in the midline of the cord.
What is Brown-Sequard Syndrome
o Lesion causing hemisection of the spinal cord
o All ascending pathways on one side of the cord are lost
o Fine touch and vibration lost below level of the lesion on the ipsilateral side
Dorsal Columns travel up cord on ipsilateral side and decussate in the Ventral Medulla
o Pain, Temperature, Crude Touch lost below level of the lesion on the contralateral side
Spinothalamic Tract decussates in the spinal cord, thus the lesion will effect fibres originating from the contralateral side
