[Dr.Ahmed Moussa]

النهارده إن شاء الله
بنزل محاضره فسيولوجي جديده
لدكتور محمد أنس
يارب تعجبكوا..

REFLEX ACTION

It is the functional unit of the nervous system.
It is the response to peripheral stimulation

Types of reflex action

local axon reflex:

It is a primitive reflex present in lower animals with incomplete nervous system.
It consists of:
a) Receptor
b) Afferent
c) Efferent (branch of afferent & has no center).
Impulses originated in the skin receptors pass via a short collateral of the afferent fiber to the effector organ e.g. blood vessels without reaching the center in CNS.
Examples of local axon reflex:
1- Secretion of gastrin hormone.
2- Secretion of suucus entericus.
3- Peristaltic movement of the intestine.
4-spreading flare of triple response.

Unconditioned reflex

Inborn reflexes.
Do not depend on previous training & don't require the integrity of cerebral cortex.
Their centers are present in CNS below the level of C.C.(cerebral cortex) i.e. in brain stem & spinal cord
Example: Introduction of food in the mouth the reflex is secretion of saliva.

Conditioned reflex

Acquired reflexes.
Depend on previous training.
Require the integrity of the cerebral cortex.
Their centers are present in the cerebral cortex.
Example : Vision or olfaction of food the reflex is secretion of saliva

ترجمه بعض الكلمات :
فعل رد الفعل أو الفعل المنعكس reflx action
محور axon
بدائي primitive
عصب حسي أو وارد afferent
عصب حركي أو صادر efferent
النبضات العصبيه impulses
جانبي أو فرعي collateral
نسيج fiber
إفرازات معويه succus entericus
الحركه الدوديه peristaltic movement
الأمعاء intestine
الجمره المنتشره spreading flare
الإستجابه الثلاثيه triple response
إفراز secretion
غير مكتسب inborn
تكامل integrity
القشره المخيه cerebral cortex
جذع الدماغ brain stem
اللعاب saliva
مكتسب acquired
شم olfaction