Pyramidal Tract Flashcards
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“ ولا خوف عليهم ولاهم يحزنون “
Define Descnding Pathways
They are Motor pathway deliver motor repsones or instruction from cerberalcortex to spinal cord
Divded into :
Pyramidal : Direct from corticospinal + corticobulbar
ExtraPyrmidal Indirect path
Descnednig pathways are subdivided into ?
Pyramidal direct pathway
Extrapyramidal indirect pathway
Pyramidal = ?
Coticospinal + CorticoBulbar Tracts
Corticospinal tract contain ?
Lateral + Anterior Corticospinal Tract
as we know sensory path have 3 neurons /
first ordere DRG
Seond order differs
3rd order from thalamus
Motor pathways involve ,……Neuronos and name them .
2 Neurons
Upper Motor Neuron
Lower Motor Neuron
Origin of Pyramidal Tracts
Cotricospinal tract
Motor area 4 + Premotor Cortex area6
Motor area 4 gives the pyramidal Neurons
UMN of pyramidal tracts are ?
their axons form ?
Pyramidal Neurons of area4 are UMN of Pyramidal Tract
Their Axons Form? the corticospinal Tract
Lateral Corticospinal Tract lies …….. to Dorsal or posterior spinocerbellar Tract ?
Medially
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Anterior coricospinal tract lies Medially to ,,,,,,,,,+,,,,,,,,,?
Reticulospinal + Tectospinal Tract
Transvers pontine fibers give definition ?
Fibers arising form Pontine Neucli Present in the Pons separating bundles of fibers of pyramidal tract
LMN ? Define
The Anterior horn Motor neurons exist spinal cord as anterior root .
Course in brain of pyramidal tract
starts from precetnral gyrus primary motor area 4 + premotor cortex 6 .
Axons of neurons in the cerberal cortex converge in Corona radiata and occupies the anterior 2/3 of posterior limb of Internal Capsule between Thalamus and basal ganglia
Posterior limb of internal capsule is located between ?
Thalamus and basal ganglia
Course of Pyramidal Tract in Midbrain explain ?
The middle 3/5 of crus cerberi which is the anterior part of cerberal peducle of Midbrain
Course of Pyramidal Tract in Pons explain
Pass through most anteiror part of pons called Basis Pontis Scattering as Bundles Separated By Transvers pontine Fibers
Where do the fibers form the pyramid ?
The pyramid is formed at convegence in cerebral cortex+
The fibers form Pyramid In the
Where do the fibers form the pyramid ?
The pyramid is formed at convegence in cerebral cortex+
The fibers Collect to form Pyramid In the medulla
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Where does pyramidal decussation occur ?
It occurs at the most lower part of medulla also called
Motor decussation by 80% of fibers of pyramid to desdcends to Laterallll Coritcopsinal tract
The Remeaning 20% continues in the same side without decussation to Anterior Coricospinal Tract will decussate in spinal cordDD
describe in brief the path of pyramidal tract to The spinal cord
In cortec : axons collects as Pyramid from area 4+6
then corona radiate then pos limb of internal capsule
In Midbrain : Crus Cerebri
In Pons : Basis Pontis
In medulla : pyramid :
a- 80% motor ducssation + lateral coricospinal tract
b-20% uncrossed +anterior Corticospinal tract to Deucssate in spinal cord to reach AHCs
Antreior horn is divided into ?”
Lateal +Medial+central Groups
Muscles of limbs are supplied by which group of Anterior Horn ?
The Lateral Group for Limb Muscles
From Cervical + Lumbar Enlargments
Represent termination of Lateral Corticospinal tract
From cervcial and Lumbar enlargmetns appear ?
The lateral group of AHCs
form Muscles of Limbs
Medial Group of Anterior horn explain
For Trunk Muscles
From all Segments !