Ascending Tracts Flashcards
Conscious tracts
DCML pathway
Anterolateral system
Unconscious tracts
Spinocerebellar tracts
DCML carries what sensory modalities?
Fine touch
Vibration
Proprioception
How many neurones are involved in the DCML?
3
First order neurones carrysensory information to where?
Medulla oblongata
Signals from the lower limb are carried in what specific part of the DCML?
fasciculus gracilis
Signals in the fasciculus gracilis synapse onto what?
gracile nucleus of the medulla oblongata
Signals from the upper limb are carried in what specific part of the DCML?
Fasiciulus cuneatus
Signals in the fasciculus gracilis synapse onto what?
Cuneate nucleus of the medulla oblongata
What happens to the fibres of the DCML pathway in the medulla?
They decussate
Second order neurones travel in the what relative to the side of initial sensory input to where?
Contralateral medial lemniscus to the thalamus
Third order neurones take the signals where in the DCML?
From the ventral posterolateral nucleus of the thalamus to the primary sensory cortex (post-central gyrus)
What modalities does the anterior spinothalmaic tract carry?
crude touch and pressure
What modalities does the lateral spinothalmaic tract carry?
pain and temperature
The anterior and lateral spinothalamic tracts make up what?
The anterolateral system
How many neurones are involved in the anterolateral system?
3
What happens to first order neurones of the anterolateral system?
Arise from the sensory receptors in the periphery. They enter the spinal cord, ascend 1-2 levels, and terminate at the tip of the dorsal horn (the substantia gelatinosa).
Second order neuroes of the anterolateral system carry information from the substantia gelatinosa to the what?
Thalamus
What happens to the second order neurones of the anterolateral system after it synapses at the substantia gelatinosa?
It decussates and anterior and lateral spinothalamic tracts split functionally but run alongside each other
Where do third order neurones of the anterolateral system, ascend from towards the primary sensory cortex?
Ascend from teh ventral posterolateral nucleus of the thalamus, through the internal capsule, terminating at the sensry cortex
The spinocerebellar tracts do what?
Transmit unconscious proprioceptive information from the muscles to the cerebellum.
