مقدمة الجهاز العصبي الحركي Flashcards
بسم الله الرحمن الرحيم وبه نستعين
“سنريهم آياتنا في الآفاق وفي أنفسهم حتي يتبين لهم أنه الحق “
Define Motor Nervous System
System responsible for
Intiation + Coordination +Control of Skeletal Muscle Contraction
بسم الله الرحمن الرحيم وبه نستعين
“سنريهم آياتنا في الآفاق وفي أنفسهم حتي يتبين لهم أنه الحق “
Define Motor Nervous System
System responsible for
Intiation + Coordination +Control of Skeletal Muscle Contraction
Motor of Facial Muscles is controlled by?
Nuclei of Motor Cranial Nerves
Motor of body muscles is controlled by ?
AHCs of Spinal Cord
If UMN is cut leads to ?
Voluntary contarction loss
Reflex is intact but is not as usual
IF LMN IS CUT ?
Loss of Both voluntary and Reflex Movments
Type of skeletal muscle contration ?
Voluntary purpoful
Reflex automatic
Mention example of voluntary mocments
Fine Movements :
Fingers + hands called
distal limb muscles
Gross Movements :
Axial muscles: back
Proximal limb muscles: Arm
Learned Skilled Movments = Fine+Gross movements as piano playing
Requirements of Voluntary muscle contraction mention
Intact Mucles
Intact UMN
Intact LMN
Reflex Muscles contraction requiremts?
Intact muscle
intact Reflex Pathway
Intact LMN
Reflex contracion as ?
Muscle ToOone
Antreior horn cells has 2 types of neuron mention
Anterior motor neuron to SM
Interneurons Intermediate
Antreior horn cells has 2 types of neuron mention
Anterior motor neuron to SM
Interneurons Intermediate
types of anterior motor neurons
alpha +gama
alpha motor neuron called ?
Lower motor neuron
Final common path
to odrinary contractile extrafusal muscle fibers
Why alpha motor neuron called final common path ?
that is because whether the muscles contracted Voulnatry or Reflexly it needs in the end to send impusle to lower motor neuroooon
somatotopic organiztation of a motor neurons
يعني خريطة توزيع الالفات
medial part of Anterior horn supply ?
-Axial +Proximal limb muscles
-Gross Movements + Posture
Dorsolateral part of Anterior horn supply?
Distal limb muscle
For fine movments
Dorsal part of anterior horn for ?
Flexors
ventral part on anterior horn for ?
Extensors
In plexus area in spinal cord
Cervical + Lumbosacral enlargments there is ?
Numerous alpha motro neurons
Below………………… alpha motor neurons control axial Muscles only
Below T1
Functional unit used by motor system to perform movments? give defintion ?
Motor Unit
It is the alpha motor neuron+ its axons + Muscle fibers supplied
Mortor unit for muscles of fine movments supply
3-6 fibers
Low Inervation ration
Motor unit for muscles of gross movments suupply
200-300 fibers
High innervation ration
Defina Motor Neuron Pool
كل اعصاب الفا الي بتغذي عضلة واحدة عصبيا
all aplha motor neurons innervating Single muscle
Motor neuron pool depends on one segment of spinal cord? ????
No!
May extedns in several segments in spinal cord as
Quadriceps from
L2+L4 segments
List the Factors affecting Discharge or rate of alpha motor Neurons .
1-Projections from higher centers
2-Interneurons
3-Endings of Sensory neurons in dorsal horn
any contraction of muscle occures through activation of ?
alpha motor neurons
Function of Gamma motor neurons
-Specialized for Contractile Intrafusal Fibers in Muscles spindle
-They are smaller and fewer
Axons called AY 4micro diameter
mention types of gamma neurons
Large dynamic efferent y neuron
Small static efferent y neuron
Compare between a and y neruons in percentage
a 65
y 35
Compare between a and y neruons in size
a larger
Compare between a and y neruons in size
a larger neurons
y smaller
Compare between a and y neruons in fucntions
a: Ordinary contractile extrafusal muscle fibers
y: specialized contractile intrafusal muscle fibers in msucle spindle
Compare between a and y neruons in size in anterior horn
A: Take the larger size
y ; take smaller size
Compare between a and y neruons in types
alpha: one type
Y 2 :
Large dynamic+ Small Static
اكتب نبذة عن خصائض الاعصاب الوسطية
منتشرة في كل مناطق المادة الرمادية للحبل الشوكي وحجمها صغير عشان كده الاستثارة بتاعتها بتكون سهلة لدرجة انها ممكن تطلق نبض بدون تحفيز اصلا
عددها 30 مرة اكتر من الاعصاب الحركية كلها علي بعضها الفا وجاما
زي اعصاب رينشو الوسطية التثبيطية
Mechanism of actin of Inhibitory renshaw Neurons .
Activated by ach from Activated a motor neuron
then Cause?
1-Reuccrent inhibition or Negative Feed back Inhibition to the a motor neurons that activated it by glycine
2-Lateral Inhibition to naerby unactivated a motor neurons by glycine
site of Renshaw ?
Ventral Horn of Spinal cord
What is the function of Renshaw ?
Lateral inhibition : Sharpening of Actions of muscles
Recurrent Inhibtion: Prevents Overexcitation of Muscles and limit discharge of Alpha motor neuron
معني رد الفعل ؟
ربط بين الجهاز العصبي الحسي والحركي
مكونات رد الفعل ؟
reflex arc components
Receptor
Afferent
Center
efferent
effector
Mention Charctertistics of Reflex ?
anis : -Automatic
-NonConscious
-Inborn
-Standarized
Mention Charctertistics of Reflex ?
-Automatic
-NonConscious
-Inborn
-Standarized
الحمدلله علي نعمه لاتعد ولا تحصي
اعوذ بك ربي من كفران النعم
types of relfelxed according to center
Cortical
HypoThalamic
Midbrain
Medullary
Spinal
KHM2S
كلمني كلام كهمس~ لم افهم منه شئ
type of reflexex according to synapse
Mono
Bi
poly synaptic