Ascending Pathways Flashcards
What are the functions of the dorsal column medial meniscal tract?
Fine touch
Vibration
Proprioception
What are two conscious tracts?
Dorsal column medial meniscal
Antero-lateral
How many neurones are involved in the dorsal column medial lemniscal tract?
3
Where does the first order neurone of the dorsal column medial lemniscal tract arise and where does it end?
Dorsal root ganglion to either nucleus gracilis or nucleus cuneatus in medulla oblongata
What is the pathway for the upper limb for dorsal column medial meniscal tract?
Fasciculus cuneatus
What is the pathway for the lower limb for dorsal column medial meniscal tract?
Fasciculus gracilis
Why does the second order neurone of the dorsal column medial lemniscal tract begin and where does it end?
Gracilis/cuneatus nucleus in medulla
Ends in the ventral posterolateral nucleus of thalamus
Why does the third order neurone of the dorsal column medial lemniscal tract start and end?
Starts in ventral posterolateral nucleus of thalamus
Ends in the sensory cortex
Where does the dorsal column medial meniscal tract desiccate?
Medulla
What is the function of the anterior spinothalamic tract?
Crude touch and pressure
What is the function of the lateral spinothalamic tract?
Pain and temperature
Where do the first order neurones for the anteriolateral system arise and end?
Arise in dorsal root ganglion and end in substantia gelatinosa of dorsal horn
Where do the second order neurones of the anteriolateral system arise and end?
Arise in the substantial gelatinosa are as either the anterior spinothalamic tract or the lateral spinothalamic tract and end in the ventral posterolateral nucleus of thalamus
Where do the third order neurones of the anterolateral system arise and end?
Ventral posterolateral nucleus of thalamus and end in the sensory cortex
Where does the anterolateral tract dessucate?
Spinal cord
What are the unconscious proprioception tracts?
Cuneocerebellar
posterior spinocerebellar
anterior spinocerebellar
Explain the pathway of the anterior spinocerebellar tract
Dorsal root ganglion -> spinal-cord grey matter where it decussates -> cerebellum
Explain the pathway of the posterior spinocerebellar tract
Dorsal root ganglion -> grey mater of spinal-cord -> cerebellum
Explain the pathway of the cuneocerebellar tract
Dorsal root ganglion -> nucleus cuneatus -> cerebellum
What are the unconscious tracts responsible for?
Unconscious proprioception and also important for brain coordination and refining motor movements
What is the anterior and posterior spinocerebellar tract responsible for?
Carrying proprioceptive information from the lower limb to the ipsilateral cerebellum
The anterior decussates twice and the posterior does not decussate
What is the rostral spinocerebellar tract responsible for?
Carrying proprioceptive information from the upper limbs to the ipsilateral cerebellum
What can lesion of the dorsal column medial lemniscal tract be caused by?
Vitamin B12 deficiency and tabes dorsalis so neurosyphilis
What is brown sequard syndrome?
A hemisection of the spinal-cord most likely due to trauma and involves that anteriolateral system and the dorsal column medial lemniscal pathway
What happens if the spinocerebellar tracts are injured?
Ipsilateral loss of muscle coordination but unlikely to be damaged alone often descending motor tracts are damaged which causes muscle weakness or paralysis and sometimes loss of muscle coordination is masked
