A Table of Actions for the Sympathetic and Parasympathetic Divisions

Effector Organ

Sympathetic Effects (receptor)

Parasympathetic Effects (receptor)

Eye (iris)

Contraction of dilator pupillae muscles – mydriasis (α1)

Contraction of sphincter pupillae muscles – miosis (M)

Eye (ciliary muscle)

Relaxation (β2) for distant vision

Contraction (M) for accommodation of lens (near vision) and increase aqueous humor outflow into canal of Schlemm

Eye (ciliary body epithelium)

Increased aqueous humor production (β1)



Increased heart rate, increased force of contraction and increased conduction rate (β1)

Decreased heart and conduction rate (M), decreased atrial contractility (M)

Arterioles(skin,abdominal viscera, kidney)

Strong vasoconstriction (α1)


Arterioles(skeletal muscle)

Weak vasoconstriction (α1)
Vasodilation (β2)



Vasoconstriction (α1), Vasodilation (β2)



Dilates Bronchioles (β2)

Constricts bronchioles (M)

Uterus, pregnant

Constriction (α1), relaxation (β2)

Contraction (M)

Gastrointestinal tract wall

Decreased tone (α1,α2,β2)

Increased tone (M)

Gastrointestinal tract sphincter

Contraction (α1)

Relaxation (M)

Gatrointestinal tract secretion


Increased (M)


Increased renin release (β1)


Bladder wall (detrusor muscle)

Relaxation (β2)

Contraction (M)

Internal urinary sphincter

Contraction (α1)

Relaxation (M)


Decreased insulin secretion (α2), decreased exocrine secretion (α)

Increased insulin secretion (M), increased exocrine secretion (M)

Fat cells

Lipolysis (β3)



Glycogenolysis (α1,β2), Gluconeogenesis (α1,β2)


Piloerector muscles of skin

Contraction (α1)


Salivary gland

Constriction of vessels & small production of a viscous saliva. (α1)

Dilation of vessels & large production of thin saliva (M)

Sweat gland

Generalized sweating (M) Localized sweating(stress) – palms & soles (α1)


Adrenal medullae

Increased secretion of EPI or NE (N)


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