the spinal cord and periphery Flashcards
what part of the spinal cord contains grey matter?
central part
what part of the spinal cord contains white matter?
peripheral parts
what are the two areas of grey matter?
dorsal and ventral horns
what is contained within the dorsal horn?
the axons of sensory fibres enter through the dorsal root into the dorsal horn of grey matter
what is contained within the ventral horn?
motor neuron cell bodies
what is a tract?
axons transmitting information between higher centres in the brain and peripheral nerves
what kind of information do ascending tracts carry?
sensory
what kind of information do descending tracts carry?
motor
what are the 3 columns that white matter is arranged in?
posterior
lateral
anterior
what are some common features of ascending spinal tracts?
there are 3 neurons between the peripheral receptor and cortex
at the synapse between the 3rd order neuron and the 2nd order neuron the 2nd order neuron crosses over to the contralateral side in the spinal cord or medulla
what makes up the posterior column?
gracile and cuneate fasciculi
what afferent information is carried to the brain via the posterior column?
fine touch
tactile localisation
vibration sense
proprioception
what does the lateral spinothalmic tract on the right side of the body transmit?
pain and temperature from the left side of the body (and vice versa)
where do the descending tracts of the spinal cord originate?
cerebral cortex and brainstem
how many neurons do descending tracts that originate in the spinal cord have in their pathway?
2
where do descending tracts decussate?
they decussate to the opposite side in the brainstem
what does the pyramidal tract control?
voluntary skilled movements
what supplies the pyramidal tract?
middle cranial artery
where do the corticobulbar fibres terminate?
brainstem
where do the corticospinal fibres terminate?
spinal cord
what is the lower motor neuron responsible for?
muscle tone and reflexes
what happens if the UMN is damaged with the LMN intact?
reflexes and tone are exaggerated
what is a reflex?
an involuntary stereotyped pattern of response brought about by a sensory stimulus
where are spinal reflexes mediated?
level of the spinal cord
what does the autonomic nervous system refer to?
nerve cells concerned with innvervation and control of visceral organs, smooth muscles and secretory glandds
