Sensory Pathways (Task 1) Flashcards
Info carried in Dorsal Column Medial Lemniscal (DCML) Tract
Fine Touch
Proprioception
Vibration
Info carried in Anterior Spinothalamic Tract (Anterolateral System)
Crude Touch
Pressure
Info carried in Lateral Spinothalamic Tract (Anterolateral System)
Pain
Temperature
Symptoms of lesions above and below decussations
Above - contralateral symptoms
Below - ipsilateral symptoms
Tracts carrying unconscious proprioception info
Spinocerebellar Tracts
Impact of a posterior spinal artery blockage
Ischaemia to dorsal column medial lemniscal tract
Impact of an anterior spinal artery blockage
Ischaemia to anterolateral tracts (anterior and lateral spinothalamic tracts)
Two parts of the DCML tract
Fasciculus Gracilis (Medial) Fasciculus Cuneatus (Lateral)
Neurons that travel in fasciculus gracilis of DCML
First order neurons from upper limbs (T6 and above)
Neurons that travel in fasciculus cuneatus of DCML
First order neurons from lower limbs (T6 and below)
Nuclei where DCML first order neurons synapse
Nucelus Gracilis and Nucleus Cuneatus in Medulla Oblongata
Synapse point of second order neurons in DCLM pathway
Contralateral Thalamus
Decussation point of DCML pathway
Medulla Oblongata after first order neuron synapses with second order neuron
Path taken by third order DCML neuron
Ventral Posterolateral Nucleus of Thalamus > Internal Capsule > Synapse at Primary Sensory Cortex
Path of first order neuron in anterolateral tracts
Enters Spinal Cord
Ascends 1-2 Vertebra
Synapse in Dorsal Horn at in Substantia Gelatinosa
Decussation point of aterolateral tracts
Spinal cord after first order neuron synapses with second order neuron
Path of second order neuron in anterolateral tract
Decussates in spinal cord and splits into two
Pain and temperature travel in lateral spinothalamic tracts
Crude touch and pressure travel in anterior spinothalamic tracts
Both paths synapse in thalamus
Path of third order neuron in anterolateral tract
Ventral posterolateral nucleus of thalamus > Internal capsule > Sensory Cortex
Symptoms present in a LEFT sided spinal lesion at T4
LEFT (ipsilateral) sided loss of DCML functions - fine touch, proprioception and vibration below T4 as lesion is below the decussation point
RIGHT (contralateral) sided loss of anterolateral functions - crude touch, pain and temperature below T4 as lesion is above the decussation point
LEFT (ipsilateral) sided hemiparesis below T4 as lesion is below decussation point of majority of descending motor tracts
Hemi-section of the spinal cord
Brown-Sequard Syndrome
