Ascending neural pathways Flashcards
what does fasciculus grascilis carry
information from lower body extremities
what does fasciculus cuneatus carry
upper body extremeties
what do the dorsal and ventral spinocerebellar tracts carry
proprioceptive information from muscle spindles and golgi organs
what do the spinal thalamic tracts carry
pain (anterolateral system)
what does a large area in the sensory homunculus represent
areas fed by nerves with small receptive fields
what are the three principle ascending tracts in the spinal cord
dorsal column medial lemniscus pathway
spinothalamic pathway
spinocerrebellar
what could cause a gait ataxia
dorsal column medial lemniscus pathway pathology
proprioception, touch pressure and vibration deprived
what is sensory ataxia
loss of coordination caused by a loss of sensory input
patient may be able to compensate using vision
a patient presents with paraesthesia in the fingers and toes. what is a possible cause
dorsal column disease
due to ectopic discharge in dorsal column axons
what are you looking for when testing the ability to feel a tuning fork vibration or position of fingers and toes
dorsal column function
what column carries fine touch
dorsal column
what pathway carries crude or non discriminating touch
spino thalamic
which pathway contains fibres that are quick to cross
spino thalamic
what fibres carry dull pain and itch
C
what pathway contains neurons that synapse in the dorsal horn
spinothalamic
what fibres are found in the lateral spinothalamic route
mix of Ad and C fibres
what fibres are carried in the ventral spinothalamic anterior route
only C fibres
what can lateral spinothalamic tract lesions cause
decreased perception of pain and temp on the contralateral side
also shooting/electrical type pain
what is the purpose of the spinocerrebellar pathways
carry information from muscle spindles and golgi organs and touch receptors to the cerrebelum for control of posture and coordination of movement
how many neurons are found in the spinocerrebellar tract
just first and second order
located in the dorsal horn of the spinal cord and teminate in the vermis of the cerrebelum
which spinocerrebellar neurons ascend ipsilaterally and enter the cerebellum via the inferior peduncle
dorsal tract neurons
what is Friedreichs ataxia
spinocerrebellar tract becomes increasingly ineffective
frataxin repeat gene
reeling gait
intention tremour
uncoordinated arm and leg movement
