The Spinal Cord and Periphery Flashcards
Where do the cell bodies of the ventral horns (motor neurons) reside?
In the ventral horns of the spinal cord (grey matter)
What is Motor Neuron disease?
A group of diseases affecting the motor neuron in the ventral horn of the spinal cord - the lower motor neuron
The neuron dies and the supplied muscle atrophies
Progressive and incurable
Is all sensory information sent to the brain before it is acted on?
No, some is too urgent and is dealt with as reflexes where the spinal cord or other lower centres making the decision
What is the name of reflexes mediated at the level op the spinal cord?
Spinal reflexes
Name a monosynaptic spinal reflex
Stretch reflex
Name a polysynaptic spinal reflex
Flexor reflex
What part of the spinal cord is grey matter?
The centre
What part of the spinal cord is white matter?
The periphery
What are the basic components of the white matter?
Tracts made up of axons transmitting information between the higher centres in the brain and peripheral nerves
What fibres do ascending tracts carry?
Sensory fibres
What fibres do descending tracts carry?
Motor fibres
What are the columns of the spinal tract?
Posterior, lateral, anterior
To where in the brain does sensory information travel?
Cerebral cortex and cerebellum
what are the common characteristics of sensory pathways reaching the conscious level?
Always three neurons between peripheral receptor and cortex
What sensory information is carried in the posterior or dorsal column?
Fine touch, tactile localisation, vibration sense, proprioception
Where does the first order neuron synapse in the dorsal column?
In the gracile and cuneate nucleii of the medulla
Where does the second order neuron of the dorsal column synapse?
In the VPL nucleus in the thalamus (of diencephalon)
To where does the third order neuron of the dorsal column travel?
The post central gyrus of the parietal lobe
What sensory information is carried in the lateral spinothalmic tract?
Pain and temperature from the contralateral side