Pyramidal Tract Flashcards
بسم الله الرحمن الرحيم وبه نستعين
“ 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
شوفت الاحوال بتتغير؟ !
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
عندك هرمين خوفو وخفرع
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 !
All segments of spinal cord gives…. in anterior horn ?
Medial group for Tunk Muscles
Central group of Anterior horn cells explain
From Cervical Segments only!
C3-C5 for Phrenic Nerve
C5 OR C6 cervical segmetns give acessoy nuclesu for spinal acessory nerve ?
Central group of Anterior horn cells explain
From Cervical Segments only!
C3-C5 for Phrenic Nerve
C5 OR C6 cervical segmetns give acessoy nuclesu for spinal acessory nerve ?
C3-C5 segmetns give
C3-C5 for Phrenic Nerve
C5 OR C6 cervical segmetns give
C5 OR C6 cervical segmetns give acessoy nuclesu for spinal acessory nerve ?
Represent termination of Lateral Corticospinal tract
Lateral group of Anterior Horn supply the limb muscles
uncrossed 20% fibers terminate as
anterio corticospinal tract in Medial group of Anterior Horn
supplying trunk
Only 2% of pyramidal tract fibers terminate at?
Spinal accessory necuels for Spinal Acessory Nerve for ?
SternoMastoid
Second Or alternative termination of Pyramidal tract fibers ?
Some pyramidal tract fibers or corticospinal fibers terminate at Cranial nerves Nuclei in brainstem Forming Cortico Nuclear or CorticoBulbar Tract
CorticoNuclear Or Cotricobulbar tract
Formed when fibers of pyrmaidal tract terminate in the Cranial Nerve Nuclei at brainstem
It supplies Muscles of Head
CorticoNuclear Or Cotricobulbar tract path
from corona radiate to !!!
The Genu !! of internal capsule to the Cranaul nerve Nuclei …
in opposite to corticospinals that pass through post limb of internal capsule
Cortiobulbar or CotricoNuclear supplies …..+…… ?
Contralateral+Ipsilateral Cranial Nerve Nuclei
Are all cranial nerve ncueli receving bilateral fibers from Corticobulbar and CorticoNuclear?
no Moslty they receive contra +ipsi but there are 2 Nucelis Receving only Contra which
are:
Lower half of ?
Facial for lower facial Muscles
Hypolglossal For Genioglossus
COntttttttra Only
Are all cranial nerve ncueli receving bilateral fibers from Corticobulbar and CorticoNuclear?
no Moslty they receive contra +ipsi but there are 2 Nucelis Receving only Contra which
are:
Lower half of ? u
Facial for lower facial Muscles
Hypolglossal For Genioglossus
COntttttttra Only
upper half of facial nucleus is ?
Bilateral Conta+ipsi while the lower half only contra
Upper motor Neuron of Pyramidal tract is ?
The fibers of pyramidla tract descending from cortex to reach :
A-spinal cord AHCs
B-Cranial Nerve Nuclei
Lower motor Neuron of Pyramidal tract is ?
A- FIBERS Of AHCs of Spinal cord which give ventral root to Muscles
B-fibers from Cranial Nerve Nuclei That Reach Muscles of FACE
in Brain sterm Nuclei recieve Coricobulbar tract?
1-GSE 3,4,6,12
general somatic efferent Nuclei
2-SVE 7.9.10.11
Sepcial visceal Efferent Nuclei
gse NUCLEI
general somatic Efferent Nuclei3,4,6,12
For extraocular Muscles +Tongue
ExtraOcular Muscle :
Occlumotor 3
Trochlear4
Abudcent6
Tongue :
Hypoglossal12
SVE nuckei
special visceral efferent Efferent nuclei : 5,7,9,10,11
Trigeminal First pharyngeal arch muscels of Mastication .
Facial for facial expressive muscles 2nd pharyngeal arch
Ambigus Nucleus : 9,10,11
Glossophayngeal:3rd pharyngeal arch stylopharyngeus
Vagus:4th 6th arch palate larynx pharunx muscle
Acessory:4th 6th arch palate larynx pharunx muscle
Trigeminal Nucelus supply ?
First pharyngeal arch muscels of Mastication
Facial Nucleus supplies?
Facial for facial expressive muscles 2nd pharyngeal arch
Ambigus Nucleus :supplies ?
9,10,11
Glossophayngeal:3rd pharyngeal arch stylopharyngeus
Vagus:4th 6th arch palate larynx pharunx muscle
Acessory:4th 6th arch palate larynx pharunx muscle
Glossophayngeal:
3rd pharyngeal arch stylopharyngeus
Vagus:
Acessory:
4th 6th arch palate larynx pharunx muscle
CorticoBulbar not involve ?
Special sense 1,2,8 Nuecli
Face is in …… area of motor cortex ?
Lower
as body represnation is upside down or inverted
Foor is in …area of Motor cortex?
Medial surface of cerebral hemisphere as body represnation is upside down or inverted
In the internal capsule what happen for both tract mentioned above ?
corticospinal
Corticobulbart
Corticospinal post limb of internal capsule as anterior upper limb + loer limb motor
CorticoBulbar genu of Internal Capsule as in Face muscles
Lamination in crus cerebri ?
From medial to lateral
Cervical
Thoracic
Lumbar
Sacral
also laminatyion in spinal cord do so
Cortiocspinal tract need …For baby to walk in ..year ?
Myelination
Second
If UMN in pyramidal Tract cut leads to ?
Loss of its supressive effect on AHCs
HyperReflexia
HyperTonia
may leasds to atrophy due to no use of muscles
Spasticparalysis
+Babeniski
If LMN of Pyramidal Tract Cut This leads to ?
No respone from muscle due to cut of its communcation with CNS
Loss of tone
loss of reflex
Flaccid paralysis
soft paralysis
-Babenski
Babinski sign occurs in Cut UMN explain ?
On mechnical stimulatio nof outer edge of sole of foot leads to DorsiFlexion of Big toe and Fanning of others
While in fact in healthy should be plantar flexed
This is called Extensor Respone
Babinski sign is positive+ in ?
الأطفال أقل من سنتين عشان مفيش-1 ميلين علي الياف الكورتيكو سبيتال
طبعا تلف العصب الحركي العلوي-
وفي الغيبوبة العميقة-
الحمدلله رب السموات رب الارض رب العالمين
الحمدلله رب السموات رب الارض رب العالمين
