Peripheral nervous system

• The parasympathetic nervous system is rest and digest
• The sympathetic nervous system is fight or flight
• Cholinergic receptors are receptors that respond to the neurotransmitter acetylcholine
• Adrenergic receptors respond to the neurotransmitters epinephrine and norepinephrine
• nicotinic receptors and muscarinic receptors are cholinergic receptors
• alpha 1, alpha 2, beta 1, and beta 2 receptors are adrenergic receptors
• Parasympathetic/cholinergic response include constricted pupils, increased secretions (saliva, tears), decreased heart rate, vasodilation (blood vessels return to normal), bronchoconstriction (lungs), increased GI motility, increased gastric secretions, and increased urine output
• Sympathetic/adrenergic responses include dilated pupils, decreased secretions (saliva, tears), increased heart rate, vasoconstriction (blood vessels), bronchodilation (lungs), decreased GI motility, increased glucose levels, decreased urine output, renin release by the kidneys (increased blood pressure), and increased sweating
• alpha 1 receptors are located in the eyes (pupils), bladder, and blood vessels; they are triggered by the neurotransmitters epinephrine, norepinephrine, and dopamine
• alpha 2 receptors are located in the CNS and are triggered by norepinephrine and epinephrine
• beta 1 receptors are located in the heart and kidneys; triggered by norepinephrine, epinephrine, and dopamine
• beta 2 receptors are located on the lungs, liver, uterus, GI tract, skeletal muscles, and arteries of vital organs; triggered by epinephrine only