Spinal Cord and Periphery Flashcards
3 important tracts?
Corticospinal/Pyramidal tract
Posterior/Dorsal column
Lateral spinothalmic tract
what is the corticospinal/pyrimidal tract?
carries motor impulses from motor cortex to skeletal muscles
posterior/dorsal column?
carries sensation of fine touch, tactile localisation, vibration sense, proprioception
corticospinal tract facts? (2)
longest
2/3 CST originates in area 4+6 frontal motor cortex the rest is somatosensory
A smaller tract? (RST)
rubrospinal tract - starts in the red nucleus of midbrain and receives input from same cortical areas as CST
Lesion at CST and RST causes?
fine movement of arms and hands lost
loss of movement in shoulders, elbows, wrists and fingers independently
Lesion at CST alone?
same deficit by functions reappear as taken over by the rubrospinal tract
Two ventromedial pathways control posture and locomotion?
Vestibulospinal and Tectospinal
What does vestibulospinal (VST) do?
stabilises head and neck
what does tectospinal (TST) do?
ensures eyes remain stable as body moves
Importance of area 6 neurones?
drive complex movements on either side of the body
thinking movements and doing areas of brain?
area 6 active in thinking area 4 is for doing
when is area 6 neurones fired?
when movement is made
when movement is imagined
when does putamen and caudate nucleus fire?
putamen fires before limb/trunk movements
caudate fires before eye movements
both are predictive of movements
activation of putamen is?
excitatory
globus pallidus at rest?
neurones are spontaneously active
Huntington’s disease involves?
hyperkinesia with dementia and personality disorders
hereditary, progressive and fatal
two types of reflex?
monosynaptic - stretch reflex
polysynaptic - flexor reflex
what is stretch reflex and flexor for?
stretch is important in control of muscle tone and posture
flexor helps protect body from painful stimuli
lower motor neurone disease?
group of diseases affecting the LMN in the ventral horn of spinal cord where neurones dies and the muscle supplies atrophies - progressive, incurable
