Effects of the Sympathetic and Parasympathetic Divisions of the Autonomic Nervous System Flashcards
Target organ/system: Digestive system
Parasympathetic effects
• Increases smooth muscle mobility (peristalsis) and amount of secretion by digestive system glands; relaxes sphincters
Sympathetic effects
• Decreases activity of digestive system and constricts digestive system sphincters (for example, anal sphincter)
Target organ/system: Liver
Parasympathetic effects
• No effect
Sympathetic effects
• Causes glucose to be released to blood
Target organ/system: Lungs
Parasympathetic effects
• Constricts bronchioles
Sympathetic effects
• Dilates bronchioles
Target organ/system: Urinary bladder/urethra
Parasympathetic effects
• Relaxes sphincters (allows voiding)
Sympathetic effects
• Constricts sphincters (prevents voiding)
Target organ/system: Kidneys
Parasympathetic effects
• No effect
Sympathetic effects
• Decreases urine output
Target organ/system: Heart
Parasympathetic effects
• Decreases rate; slows and steadies
Sympathetic effects
• Increases rate and force of heartbeat
Target organ/system: Blood vessels
Parasympathetic effects
• No effect on most blood vessels
Sympathetic effects
• Constricts blood vessels in viscera and skin (dilates those in skeletal muscle and heart); increases blood pressure
Target organ/system: Glands—salivary, lacrimal, Gastric
Parasympathetic effects
• Stimulates; increases production of saliva, tears, and gastric juice
Sympathetic effects
• Inhibits; result is dry mouth and dry eyes
Target organ/system: Eye (iris)
Parasympathetic effects
• Stimulates constrictor muscles; constricts pupils
Sympathetic effects
• Stimulates dilator muscles; dilates pupils
Target organ/system: Eye (ciliary muscle)
Parasympathetic effects
• Stimulates to increase bulging of lens for close vision
Sympathetic effects
• Inhibits; decreases bulging of lens; prepares for distant vision
Target organ/system: Adrenal medulla
Parasympathetic effects
• No effect
Sympathetic effects
• Stimulates medulla cells to secrete epinephrine and norepinephrine
Target organ/system: Sweat glands of skin
Parasympathetic effects
• No effect
Sympathetic effects
• Stimulates to produce perspiration
Target organ/system: Arrector pili muscles attached to hair follicles
Parasympathetic effects
• No effect
Sympathetic effects
• Stimulates; produces “goose bumps”
Target organ/system: Penis
Parasympathetic effects
• Causes erection due to vasodilation
Sympathetic effects
• Causes ejaculation (emission of semen)
Target organ/system: Cellular metabolism
Parasympathetic effects
• No effect
Sympathetic effects
• Increases metabolic rate; increases blood sugar levels; stimulates fat breakdown
