Ascending and Descending Tracts (8.1) Flashcards
Identify the key features of a transverse section of the spinal cord (grey and white matter)
Outline the blood supply to the spinal cord
Identify territories supplied by anterior and posterior spinal arteries
Identify the location of the main descending tracts on a spinal cord cross section
Describe where the main ascending and descending tracts decussate
Deduce the symptoms and functional deficits arising from spinal cord injury at a given level
Symptoms and possible site of injury
Distinguish between upper and lower motor neurons
- Upper motor neurons (UMN) orignate from a motor region of the brain and decend to the appropriate spinal cord level
‘A cell body/axon tract of a motor neuron which resides within the brain. They innervate lower motor neurons within the spinal cord or brainstem.
- Lower motor neurons synapse with UMN at the spinal cord and then travel to innervate muscles - allowing for control of muscular function
‘A cell or axon tract that exists in the ventral horn. May also exist in the motor nuclei of the brain stem, for output to cranial nerves.’
- UMN release glutamate, which acts on post-synpatic glutaminergic receptors
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Draw a basic schematic for a descending/motor pathway
How many neurons are present in the pathway?
- 2/3 neurons are present in the pathway
Describe the location and function of the corticospinal tracts
Describe the location and function of the rubrospinal and vestibulospinal tracts
Summary diagram of the the corticospinal, rubrospinal and vestibulospinal tracts
Clinical application: Spinal cord hemi-section
- Can lead to both UMN and LMN signs/symptoms in different regions of the body
Draw a basic schematic for an ascending/sensory pathway
How many neurons are present in the pathway?
