Descneding tracts Flashcards
بسم الله الرحمن الرحيم وبه نستعين
UMN IS ?
Nerves from cortex and subcortical Nuclei to the AHCs of spinal cord or Cranial Motor Nuclei
LMN IS ?
AHCs a motor neurons of spinal cord and Cranial motor Nuclei and their Axons
Some characteristic of UMNs pYRAMIDAL TRACT
From cortex
To a motor neurons of AHCs + Cranial Nerve Nuceli
60% Develops after 1 year
3%From betz cells of area 4
It is Well developed
Functions of Pyramidal Tracts
-Movements:-
Gross + Fine movements
Gross for positioning and fixation
postural background for fine movments.
To perform Fine skilled Movements in distal limb muscles
Faciltatory to Superfical and deep reflexes
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-Reflexes:-
Inhibits Babinski reflex
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-According to areas :-
-Area 4 fine
-Area 6 and supplemental gross
-Area 8 contral lateral volunary lateral conjugate eye movements
Extrapyramidal tracts in brief
From cortex motor mainly area 6
to basal ganglia which Is Distrubitive Center to the Nuceli of Extra pyarmidal tracts :
Red Nucleus = Rubrospinal
Tectum of mid brain = Tectospinal
Vestibular nucleus= Vestibulopsina;
Retiuclar formation = Reticulospinal
Inferior olivary nucleus = Olivospina
Lateral brainstem pathway in Extrapyramidals ?
Rubrospinal tract for fine movements
Medial brains stem pathaway for extrapyramidals ?
Tectospinal
Vestibulospinal
Reticulospina;l
other area that has a map for motor movemnts than area 4 ?
Red nucleus im mid brain
Termination and control of medial brainstem extrapyramidals ?
Ends on medial AHCs alpha motor neurons for ?
Axial and proximal limb muscles for gross movments and postural background for fine movements
Termination and controol of lateral brainsterm extrapyramidals ?
Ends on lateral AHCs alpha notor neurion for ?
Distal limb Muscles for Fine movements
It faciltate flexor parts of AHCs and inhivits externsors
How to compare between medial and lateral brainstem extrapyrmaidals ?
in Tracts + Termination + Control(function)
Mnetion functions of Extrapyramidal tracts
Coorfination of Voluntary movements gross and fine:
Gross movemnts for fixation and posistioningg and postural background for
Fine movements alternative pathway in rubrospinal alternative to Lateral coritcospinal in lesion
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Facilitatory and inhibtory to SR
Functional regulation of Automnomic function in CVS resp
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Tectospinal : Medial Aduial reflex
Larteal : visual reflex eye protective reflexes
Vestibulospinal Activating Alpha motor neurons for antigravity extensors muscles
How to compare between pyrmaidal and ExtraPyramidal Tracrts
Origin
tract
Crossing
Termination
Start of function
funciton
Compare between Pyramidal and Extrapyramidal tracts
Pyramidal : from cortex - One neuron from cortex to Anterior HOrn cells of spinal cord of Cranial motor nuclei one synapse -90 % crossing -start function after year - function for fine movements and gross and for ++SR
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ExtraPyramidal : cortical subcortical - Polysynaptic as go to basal ganglia then ditrbted - terminates in AHCs of spinal cord only - start during first year - Function gross movments + alternative fine movements may be
++ or– for SR
How to compare between descneding Tracts ?
TRACTS
Termination
COntrol
Lesion