autonomic nervous system

what does the sympathetic nervous system do

• fight or flight

• increased HR, respiratory efficiency (bronchodilation), pupil dilation, blood glucose, blood pressure, sweating

• decreased blood flow to GI and secretions

• urinary retention

what does the parasympathetic nervous system do

• rest and digest

• increased blood flow to GI and secretions for digestion, pupil constriction, urine (bladder contraction),

• bronchoconstriction (decreased resp efficiency), decreased HR

what do cholinergic drugs do? and what are the adverse effects

• (parasympathetic drugs) stimulate PNS by increasing ACh activity (a neurotransmitter)

• adverse effects = SLUDGE

  • salivation (excess drooling)

  • lacrimation = watery eyes

  • urinary frequency or incontinence

  • diarrhea from overactive intestines → loose stool frequently

  • GI upset = nausea, cramping, abdominal discomfort

  • emesis = vomiting

what are the contraindications for cholinergics

• think: what does the PNS do? how could this be bad?

• asthma because of the bronchoconstriction of cholinergics → worse breathing

• peptic ulcers bc increased acid and GI secretions → worsen ulcer pain and/or bleeding

• bowel or bladder obstruction - increased muscle contraction of bladder → rupture or pain if something blocks the passage

• epilepsy → stimulates the nervous system → may trigger seizures

direct acting cholinergics

• bethanechol → promotes urination

• pilocarpine → treats dry mouth or glaucoma

• cevimeline → treats dry mouth (Sjorgen’s syndrome)

• key effects:

  • SLUDGE

indirect acting cholinergics

• neostigmine

• pyridostigmine

• donepezil

• rivastigmine

• uses:

  • myasthenia gravis - for increased muscle strength

  • alzheimer’s disease - for slowing memory decline

  • glaucoma - reduces eye pressure

• key effects

  • improves muscle strength and memory

  • increases cholinergic activity

what do anticholinergic drugs do

• anticholinergics are parasympathetic blockers = block ACh receptors

• → fight or flight symptoms:

  • increased HR, urinary retention, decreased GI motility and secretions, decreased salivatoin

• adverse effects:

  • cant pee (urinary retention)

  • cant shit (decreased GI motility and secretions) → constipation

  • cant spit (decreased saliva) → dry mouth

  • cant see (pupil constriction)

  • elderly risks = falls and confusion

  • heat intolerance (reduced sweating)

what are the nursing considerations for anticholinergic drugs?

• monitor for confusion, urinary retention, constipation

• encourage: fluids and fiber

anticholinergic drug examples

• atropine

  • increases heart rate, dilated pupils (for pre-op or eye exam)

  • common side effects: can’t see, can’t pee, cant s**t, cant spit

• ipratropium/tiotropium

  • COPD inhalers → bronchodilation

  • side effects: dry mouth, cough, dizziness

• oxybutynin/Tolterodine

  • overactive bladder (reduce urinary urgency/freq)

  • common side effects: urinary retention, dry mouth

• scopolamine

  • motion sickness

  • side effects: drowsiness, dry mouth

main receptors and general roles

• beta 1 = 1 heart

• beta 2 = 2 lungs

• receptor = switch to turn organs on/off

• adrenergic = fight or flight

  • turned on by epinephrine/norepinephrine (adrenaline)

alpha 1 adrenergic receptors

• big squeeze

• location: blood vessels, iris, bladder sphincter

• stimulation effect: vasoconstriction (BV), increased BP, pupil dilation, tight bladder sphincter

alpha 2 adrenergic receptors

• 2 much, calm down

• location: presynaptic nerve membranes, pancreas

• stimulation effect: regulates NE release, moderates insulin output

beta 1 adrenergic receptors

• location: 1 heart

• stimulation effect: increased HR and contraction (1 heart)

beta 2 adrenergic receptors

• location: lungs, blood vessels, uterus

• stimulation effect: bronchodilation, vasodilation, uterine relaxation (2 lungs)

beta 3 adrenergic receptors

• location: adipose tissue, GI tract, bladder, heart

• stimulation effect: increased metabolism, lipolysis. often resistant to blocking

muscarinic (cholinergic) receptors

• location: smooth muscle, glands, heart

• stimulation effect: pupil constriction, increased GI motility, increased salivation, decreased HR

nicotinic (cholinergic) receptors

• location: CNS, adrenal medulla, neuromuscular junction

• stimulation effect: muscle contraction, NE, and epinephrine release