Reticular formation Flashcards
بسم الله الرحمن الرحيم وبه نستعين
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What is Reticular formation ?
Complex connections of Neurons in the brainstem
superiorly reaching thalamus and hypothalamus
inferiorly to motor and interneurons spinal cord
divded into :
Sensory and motor neurons
Describe Sensory neurons of reticular formation
Are interconncected togethers havig neuronal pool properities:
Convegence يجمعوا من بعض وينشطوا مكان
Divergence يوزوعوها علي بعض
AfterDischarge واحد يشتغل ويشغل الباقي
Mention afferents of sensory neurons of Reticular formation
Asceding sensory pathways + Higher centers
Ascednding pathwayS:
Spinothalamic + dorsal column + Trigeminal
Visual +audiotry + olfaction + Vestibular for balance
Higher centers :
Cortex + Basal ganglia + hypothalamus + Cerebellum
Mention motor Reticular formation components
Exictatory Ponitine Reticualr Formation
Inhibitory Medullary Reticualr Formatio
Which Motor reticular formation have Pacemaker ?
Pontine Excitatory one
Describe the pathways of Pontine reticular formation
Ascednding pathways : to cortex :
INdirect: from hypothalamus and thalamus to whole cortex
Direct to whole cortex
For arousal and awakefullness
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Descending Pathways exciting motor neruons of Antigravity muscles for position maintanence
via Ventral Reticlospinal tract
لو قل نشاط
pontine RF
ايه يحصل ؟
-Decreasing Arousal and Awakefullnes
-inhibition of motor neurons of antigravity muscles
لو قل نشاط
pontine RF
ايه يحصل ؟
-Decreasing Arousal and Awakefullnes
-inhibition of motor neurons of antigravity muscles
العوامل التي تقلل عمل
pontine excitatory reticular formation
Medullary Reticular formation
ملحوظة اللي جاي كله يشغل medullary RF:
ARBP
Area 6
Palleocerebellum
Red nucelus
Basal ganglia gllobius pallidus
Effects of Medullary RF
Inhibtiory :
Inhibition of motor neurons of antigravity muscles via lateral Reticulospinal tract.
Inhibition of Cortex in direct via inhibtion of Facilitatory RF
مين يثبط
Medullary RF ?
Pontine RF
عكسية
ARAS Is?
Ascending Reticular Activating system
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Polysynaptic pathway
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activating cortex via 2 pathways :
indirect via intralaminar + Reticular Nuclei Of thalamus
Direct whole cortex for arousal and Awakefullness
Mnetion + and - factors on ARAS
+ :
Sensory impulses pain
Cortical impulses thinking and emotions
3S:Stress+sympathtic+sympathomimetics
Analeptics+ caffiene+ thyroid
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-:
Loss of sensory and cortical impulses
Activating sleep centers
general anastheisa
ARAS Damage
Functions of Reticular formation
RAMI
1- Integration : link between higher brain centers and spinal corf
2- Pacmake : for Contiuous :
Arousal + Antigravity muscle tone
3-Regulation for Vital centers nearby
4-REM Sleep + Arousal ?
5-Modulation of Pain in analgesic system Raphe Magnus Nucleus Secreting Serotonin
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