Veterinary Neuropharmacology

COMPARISON

Criteria	Sympathetic Nervous System	Parasympathetic Nervous System
Outflow from CNS	Thoracolumbar	Craniosacral
Ganglia	Paravertebral; prevertebral close to CNS; a few intramural ganglia close to organ	Intramural ganglia-close to effector organ
Ratio of preganglionic:postganglionic	Preganglionic neurons synapse with many postganglionic neurons. Diffuse (1:20)	Preganglionic neurons synapse with few postganglionic neurons. Discrete (1:1)
Function	“Fight or flight” / energy is spent	Conservation of energy / “Live and let live” / "Rest and digest"
Effectors	Smooth and cardiac muscle, glands	Generally the same as Sympathetic
Transmitters	ACh (ganglia), NE ( Neuroeffector junction)	ACh (both at ganglia and at neuroeffector junction)

Note: Evisceration of parasympathetic outflow is life treatening unlike sympathetic outflow.