Spinal Cord Pathways Flashcards
Where are the 2 enlargements of the spinal cord?
Cervical (ie. brachial plexus) and lumbar (ie. lumbosacral plexus)
How does the cauda equine develop?
The nerve roots coming out of the base of the spine grow to become fibers – we cean draw CSF from this space without worrying about hitting the spinal cord.
How is the grey/white matter arrangement different in the spinal cord different from the cerebrum?
In the spinal cord, the white matter is on the outside
The ___ ___ horns join up to make dorsal/ventral ____, which make up the spinal nerve.
grey matter horns, dorsal/ventral roots
What does the dorsal column/medial leminiscus pathway do?
joint/limb position and proprioception, light toucch
what does the spinothalamic (anterolateral) pathway do?
pain/temperature, deep touch (pressure)
what does the spinocerebellar pathway do?
unconscious proprioception
The dorsal column crosses over to the ipsilateral side at the ____.
medulla
The spinothalamic pathway crosses over to the ipsilateral side at the ____.
medulla
The spinocerebellar pathway crosses over to the ipsilateral side at the ____.
pons
Somatic motor pathways involve at least ___ motor neurons: _______
2: upper and lower
What happens when the upper motor neuron is damaged and can no longer inhibit the lower motor neuron?
the muscle continues to contract & seize up (spastic paralysis)
What happens when the lower motor neuron is damaged and can no longer deliver information to the periphery?
The muscle can’t contract, going limp (flaccid paralysis)
What does the corticospinal pathway regulate?
the limbs & trunk
What does the corticonuclear pathway regulate?
the head & neck
What are extrapyramidal pathways used for?
back-up systems in the case of pyramidal pathway damage
Which areas of the brain are activated for simple finger flexion?
the motor cortex & somatic sensory cortex
Which areas of the brain are activated for finger movement sequencing?
motor cortex & premotor & supplementary motor area
Which areas of the brain are activated for finger sequence mental rehearsal?
premotor & supplementary motor area
What is the internal capsule?
Where all motor fibers come together and bundle in the brain
__% of axons cross over to the other side of the spinal cord as they travel down the corticospinal pathway.
85%
What happens if you have damage above the level of the midbrain?
the red nucleus is uninhibited & you lock up
What happens if you have damage below the level of the midbrain?
you can move freely, but that means RAS damage which involves becoming unconscious
