Effects of the Sympathetic and Parasympathetic Divisions of the Autonomic Nervous System

Adipose tissue

Parasympathetic effects; No effect

Adrenal medulla

Parasympathetic effects; No effect

Arrector pili muscles attached to hair follicles

Parasympathetic effects; No effect

Blood vessels

Parasympathetic effects; No effect on most blood vessels

Cellular metabolism

Parasympathetic effects; No effect

Digestive system

Parasympathetic effects; Increases smooth muscle mobility (peristalsis) and amount of secretion by digestive system glands; relaxes sphincters

Eye (ciliary muscle)

Parasympathetic effects; Stimulates to increase bulging of lens for close vision

Eye (iris)

Parasympathetic effects; Stimulates constrictor muscles; constricts pupils

Glands—salivary, lacrimal, gastric

Parasympathetic effects; Stimulates; increases production of saliva, tears, and gastric juice

Heart

Parasympathetic effects; Decreases rate; slows and steadies

Kidneys

Parasympathetic effects; No effect

Liver

Parasympathetic effects; No effect

Lungs

Parasympathetic effects; Constricts bronchioles

Penis

Parasympathetic effects; Causes erection due to vasodilation

Sweat glands of skin

Parasympathetic effects; No effect

Urinary bladder/urethra

Parasympathetic effects; Relaxes sphincters (allows voiding)

Adipose tissue

Sympathetic effects; Stimulates fat breakdown

Adrenal medulla

Sympathetic effects; Stimulates medulla cells to secrete epinephrine and norepinephrine

Arrector pili muscles attached to hair follicles

Sympathetic effects; Stimulates; produces “goose bumps”

Blood vessels

Sympathetic effects; Constricts blood vessels in viscera and skin (dilates those in skeletal muscle and heart); increases blood pressure

Cellular metabolism

Sympathetic effects; Increases metabolic rate; increases blood sugar levels; stimulates fat breakdown

Digestive system

Sympathetic effects; Decreases activity of digestive system and constricts digestive system sphincters (for example, anal sphincter)

Eye (ciliary muscle)

Sympathetic effects; Inhibits; decreases bulging of lens; prepares for distant vision

Eye (iris)

Sympathetic effects; Stimulates dilator muscles; dilates pupils

Glands—salivary, lacrimal, gastric

Sympathetic effects; Inhibits; result is dry mouth and dry eyes

Heart

Sympathetic effects; Increases rate and force of heartbeat

Kidneys

Sympathetic effects; Decreases urine output

Liver

Sympathetic effects; Causes glucose to be released to blood

Lungs

Sympathetic effects; Dilates bronchioles

Penis

Sympathetic effects; Causes ejaculation (emission of semen)

Sweat glands of skin

Sympathetic effects; Stimulates to produce perspiration

Urinary bladder/urethra

Sympathetic effects; Constricts sphincters (prevents voiding)