Disorders of Spine Flashcards
What way are the sensory fibres arranged within the spinal cord?
Fibres carrying cervical information are closest to the dorsal horn
then thoracic, then lumbar then sacral around around edge of the cord
What way are the motor fibres arranged within the spinal cord?
Descending fibres carrying information to cervical area closest to anterior horn
then thoracic, lumbar then sacral
sacral found most medially
What are the two sensory systems?
dorsal column system
spinothalamic tract
How many neurones are needed in each sensory systems?
- always use three neurones
- the first coming from dorsal root ganglion
- last neurone always in thalamus (contralateral side of dorsal)
Describe the Dorsal column tract?
- neurone enters through dorsal root ganglion
- travels immediately up dorsal column
- reaches medulla where second neurone synapses
- second neurone crosses over and travels to thalamus
- third = thalamus > cortex
What type of information is carried by the Dorsal column tract?
Fine touch and proprioception
Describe the difference in spinothalamic tract compared to DCT?
- first neurone synapses with second neurone in the dorsal horn of spinal cord
- second neurone crosses immediately
- synapses with third neurone in thalamus which travels to cortex
What type of information is carried by the spinothalamic tract?
Pain and temperature
How many neurones are involved in each motor pathway?
Two
Describe the motor pathway?
- first neurone starts in pyramidal cells in cortex
- travels through internal capsule and brainstem
- at end of brainstem crosses over
- enters spinal cord where it will synapse with second neurone in ventral horn
What are the two descending motor pathways?
Lateral corticospinal tract
rubrospinal tract
What information does rubrospinal tract carry?
- motor information to the toe
- works by suppressing the second neurone (which is why toe curls if damage to rubrospinal)
What other words can be used to describe the upper and lower motor neurone lesion?
Upper = central or first
Lower = peripheral or second
What motor changes will occur with a UMN or LMN lesion?
reduced/ missing power
What muscular tone changes will occur with a LMN and UMN lesion?
LMN - Decreased muscular tone
UMN - Increased (spastic)