Ascending tracts Flashcards
(28 cards)
What are the conscious ascending tracts?
the dorsal column medial lemniscal pathway
the anterolateral system
What are the uncoscious ascending tracts ?
the spinocerebellar tracts
What does the DCML pathway stand for ?
the dorsal column medial lemniscal pathway
What sensory modalities does the DCML pathway carry?
fine touch
vibration
proprioception
Which pathway carries the sensory modalities of fine touch, vibration and proprioception?
the DCML pathway
How many neurones are involved in the DCML pathway ?
3
Describe the function of first, second, and third order neurones in the DCML pathway
First order- carries information to the medulla
Second order- carries information from the medulla to the thalamus
Third order- carries information from the thalamus to the primary sensory cortex
Where in the spinal cord does the DCML pathway travel?
in the dorsal columns
Signals from the upper limb come from which vertebral levels?
above T6
Which part of the dorsal column do signals from the upper limb travel in?
the fasciculatus cuneatus (lateral part)
Which part of the dorsal column do signals from the lower limb travel in?
the fasciculatus gracilis (median part)
Where do the first order neurones in the DCML pathway synapse in the medulla if they are from the upper limb?
the nucleus cuneatus
Where do the first order neurones in the DCML pathway synapse in the medulla if they are from the lower limb?
the nucleus gracilis
Where do the fibres of the DCML pathway decussate?
the medulla
Which tracts make up the anterolateral system?
the anterior spinothalamic tract
the lateral spinothalamic tract
What sensory modalities does the anterior spinothalamic tract carry?
crude touch
pressure
What sensory modalities does the lateral spinothalamic tract carry?
pain
temperature
In the anterolateral system, how many vertebral levels do the first order neurones ascend in the spinal cord before synapsing?
1-2 vertebral levels
Where in the spinal cord do the first order neurones of the arterolateral system synapse?
the tip of the dorsal horn- the substantia gelatinosa
What is the function of first order neurones in the anterolateral system?
carry information from receptor to the sybstantia gelatinosa
What is the function of second order neurones in the anterolateral system?
carry information from the substatia gelatinosa to the thalamus
What is the function of third order neurones in the anterolateral system?
carry information form the thalamus to the primary sensory cortex
Where do fibres decussate in the spinothalamic tracts?
the spinal cord. Second order neurones
Which tracts carry unconscious proprioceptive information?
the spinocerebellar tracts
