Differences between Sympathetic and parasympathetic systems

	Sympathetic system	Parasympathetic system
Origin of nerves	Thoracic and lumbar region of the spinal cord	Cranial and sacral regions of the spinal cord
Main neurotransmitter	Epinephrine and nor epinephrine	Acetylcholine
Innervated organs	Eye, GIT, Respiratory system,	Eye, GIT, Respiratory system,
Purpose	Responsible for  involuntary responses, such as “fight and flight”	Responsible for essential body functions, such as elimination, feeding, and resting functions.

Differences between Sympathetic and parasympathetic   systems:

        I.            Functions of Sympathetic nervous system :    

a.       Effects of stimulation of the sympathetic system: because several actions like increase heart rate, blood pressure, mobilize energy stores of the body, increase blood flow to skeletal muscles and cardiac muscle while decreasing blood flow to the skin and other internal organs.

b.      Fight or Flight response  :  sympathetic  work actively at emergencies cases like fight or flight    it act directly by activation of effectors organs and indirect by stimulating adrenal medulla to release epinephrine and little norepinepherine and these hormones enter the blood and activate effector  organs .

c.       Although sympathetic system is continually active to some degree like  maintaining the tone of vascular beds

      II.            Functions of Parasympathetic nervous system  :

                 

The parasympathetic system  responsible for maintaining essential body function  as digestive process and elimination of wastes. It oppose or balance  the actions of sympathetic system and generally it dominant over sympathetic system in rest and digest

 
 
Drugs stimulate sympathetic system called    sympathomimetics or adrenergics
Drugs stimulate parasympathetic system called  parasympathomimetic or cholinergic