sympathetic and parasympathetic Nervous system functions

Digestive System (Parasympathetic)

Increases smooth muscle mobility (peristalsis) and secretion by digestive glands; relaxes sphincters

Digestive System (Sympathetic)

Decreases activity of digestive system; constricts sphincters (e.g., anal sphincter)

Liver (Parasympathetic)

No effect

Liver (Sympathetic)

Causes glucose to be released into the blood (glycogenolysis)

Lungs (Parasympathetic)

Constricts bronchioles

Lungs (Sympathetic)

Dilates bronchioles

Urinary Bladder/Urethra (Parasympathetic)

Relaxes sphincters (allows voiding)

Urinary Bladder/Urethra (Sympathetic)

Constricts sphincters (prevents voiding)

Kidneys (Parasympathetic)

No effect

Kidneys (Sympathetic)

Decreases urine output (via vasoconstriction and renin release)

Heart (Parasympathetic)

Decreases heart rate; slows and steadies heartbeat

Heart (Sympathetic)

Increases heart rate and force of contraction

Blood Vessels (Parasympathetic)

No effect on most blood vessels

Blood Vessels (Sympathetic)

Constricts blood vessels in viscera and skin; dilates vessels in skeletal muscle and heart; increases blood pressure

Glands (salivary, lacrimal, gastric) (Parasympathetic)

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

Glands (salivary, lacrimal, gastric) (Sympathetic)

Inhibits; results in dry mouth and dry eyes

Eye (Iris) (Parasympathetic)

Stimulates constrictor muscles; constricts pupils (miosis)

Eye (Iris) (Sympathetic)

Stimulates dilator muscles; dilates pupils (mydriasis)

Eye (Ciliary Muscle) (Parasympathetic)

Stimulates to increase bulging of lens for close vision (accommodation)

Eye (Ciliary Muscle) (Sympathetic)

Inhibits; decreases bulging of lens; prepares for distant vision

Adrenal Medulla (Parasympathetic)

No effect

Adrenal Medulla (Sympathetic)

Stimulates medulla cells to secrete epinephrine and norepinephrine

Sweat Glands of Skin (Parasympathetic)

No effect

Sweat Glands of Skin (Sympathetic)

Stimulates to produce perspiration

Arrector Pili Muscles (Parasympathetic)

No effect

Arrector Pili Muscles (Sympathetic)

Stimulates; produces “goose bumps” (piloerection)

Penis (Parasympathetic)

Causes erection due to vasodilation

Penis (Sympathetic)

Causes ejaculation (emission of semen)

Cellular Metabolism (Parasympathetic)

No effect

Cellular Metabolism (Sympathetic)

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

Adipose Tissue (Parasympathetic)

No effect

Adipose Tissue (Sympathetic)

Stimulates fat breakdown (lipolysis)