Automomic Nervous system: overview and medications Flashcards
What is the ANS affected by
- brain
- spinal cord
- vasculature
- hormones
What NT does the sympathetic NS use
- Epinephrine
- Norepinephrine
- dopamine
- adrenergic system/Ach
What NT does the parasympathetic NS use
- acetylcholine
- cholinergic system
Describe the difference between the sympathetic and parasympathetic pre and post ganglionic cell
Sympathetic:
- pre ganglionic is short/close to the spinal cord and releases ACh
- post ganglionic is long and releases Ach, NE, dopamine, EP
Parasympathetic:
- pre-ganglionic is long and releases ACh
- post-ganglionic is short and releases ACh
ANS: sympathetic nervous system overview
- neurons in spinal cord connection to sympatetic chain ganglion outside the spine
- provide input to organs, arterioles, skin
- adrenergic system or thoracolumbar
- epi, norepi, and dopamine
effects of the sympathetic NS
- increase HR and BP
- increase in heart contractility
- bronchodilation
- vasodilation to skeletal muscle
- kidney secrete renin
- sweating
- decrease GI activity
- bladder relaxes and sphincter contracts
- pupils dilate
- gluconeogensis/glycogenolysis
What is the basic function for the parasympathetic NS, where do the nerves mainly come from and what NT does it use
- neurons in brain stem or saccral spinal cord connect to cranial nerves or pelvic
- provide imputs to organs like the heart, lungs, and bladder
- cholinergic system also called craniosacral
- uses Acetylcholine (Ach)
What are the main effects of parasympathetic NS stimulation
- Decrease in HR and BP
- decreased cardiac contractility
- bronchoconstriction (this also maintains moisture)
- increase in GI activity
- bladder constricts and sphincters relax
- pupils constrict
What in the body does not have any direct parasympathetic input to
- arterioles
- kidney
- radial muscles of iris
- sweat glands
- liver
- fat cells
Autonomic NS receptors system: used in both sympathetic and parasympathetic
- Ach is used to transmit information from the brainstem or spinal cord to the autonomic ganglia
- nicotinic receptors
- these neurons then connect to peripheral structures
- used in both
Sympathetic nervous system receptors
- where are they located generally
- types
- what do they do
- the second set of neurons release norepinenphrine (after chain ganglion)
- attaches to alpha or beta receptors
- difference receptors on different organs
- can increase or decrease sympathetic input to peripheral cells
Alpha receptors in the sympathetic NS
primarily in peripheral arterioles of smooth muscle
Beta 1 receptors in the sympathetic NS
- primarily in the heart
Beta 2 receptors in the sympathetic NS
primarily in the lungs
The second set of neurons in the parasympathetic nervous system receptors
- release Ach
- Ach attaches to muscarinic receptors in peripheral cells
- increase parasympathetic effect
- muscarinic is just in parasympathetic
ANS medications: agonist - general for both sympathetic and parasympathetic
- adrenergics: stimulate sympathetic NS meaning they are agonist
- cholinergics stimulate the parasymapthetic
- mimetics = mimics which can mean an agonist also
ANS medications: antagonist - general for both sympathetic and parasympathetic
- beta blockers = inhibit sympathetic NS
- alpha blockers = inhibit sympathetic NS
- anticholinergics = inhibit parasympathetic NS
- lytics = breaks/blocks action
Drug mechanism on NT in the ANS
- action potential
- synthesis, storage, release
- postsynaptic receptor
- metabolism, reuptake, degradation
- continued NT release
Receptors and pharmacology are…
- receptor-specific drugs can target specific organs
What do cholinergic drugs typically affect
- parasympathetic system
- muscular system
- brain
Cholinergics stimulants
increase action of neurons that use Ach
what are the types of cholinergics stimulants and what do they do
- direct: bind to receptor for Ach
- block action of acetylcholinesterase so Ach can be used longer
Direct cholinergic stimulants
- how does it work
- what does it do
- receptor specificity for muscarinic receptors (so it just affects Parasympathetic)
- increases parasympathetic activity
examples of direct cholinergic stimulants
- bethanechol: treats urinary retention or ileus (take mostly after surgery due to bowel stop working and backs up the colon)
- nicotine pathes or gum
Indirect cholinergic stimulants
- increase availability of Ach by reducing the AchE
- non-specific effects: increase availability throughout the body not at a particular part
- can increase Ach activity at nicotinic receptors (which are found in sympathetic NS also)
- some drugs have specificity at certain doses
- uses: increase Ach availble at neuromuscular junction, brain, treat glaucoma, urinary retention
What are the side effects of cholinergic stimulants?
- increase in parasympathetic function…
- GI distress: nausea, vomiting, diarrhea, abdominal cramping
- bronchoconstriction and increased salivation (keeps moisture)
- bradycardia
- pupils constricted, impacts vision
Rehab considerations for cholinergic stimulants
- bronchoconstriction: pace activities (dyspnea)
- urinary frequency with abdominal contractions
- impaired vision in low light
- fall risk
Rehab considerations with nicotine
- increase in blood pressure
- non-prescription (smoking/vaping)
- decrease oxygen-carrying capacity
- increase risk of angina
cholineterase inhibitor poisoning
- caused by too much Ach
- Diarrhea
- Urination
- Miosis: pupil constriction
- Bradycardia
- Bronchospasm
- Excitation of ms
- Lacrimation
- Sweating
- Salivation
Anticholinergic drugs: antagonsits
- inhibit parasympathetic NS
- can block action of nicotinic or muscarinic receptors
- some can specifically target different subtypes (M1-M5)
- anticholinergics for nicotinic receptors which will affect both sympathetic and parasympathetic
- can target autonomic ganglia or neuromuscular junction
Uses of anticholinergic drugs
- Gi system: reduces gastric secretion, motility, GI smooth muscle tone
- used for peptic ulcers, irritable bowl syndrome
- cardiovascular: reduces bradycardia and some heart arrhythmias
- bladder: reduces contraction of bladder/reduces tone of bladder muscles
- eye: reduces pupillary constriction: dilates the eye
What can anticholinergics be used for in the brain or brain stem
- parkinsons disease: improves motor symptoms
- motion sickness
- targets problems in brain or brainstem
Anticholinergic at neuromusclar junction
- Succinylcholine
- causes temporary paralysis in a larger dose
- ## can be used during surgery or to input a ventilator to avoid them coughing it up
PT considerations for anticholinergics at neuromuscular junction
- nausea
- emesis: throwing up
- myalgia: tight muscles
- hyperkalemia
Side effects of anticholinergic drugs
- dry mouth
- blurred vision
- tachycardia
- urinary retention
- constipation
- confusion
- dizziness
- nervousness
- drowsiness
Rehab considerations for anticholinergics
- increased HR
- light sensitivity
- sedation/decrease cognition
- decreased sweating/hyperthermia
Adreneric drugs generally affect what
- sympathetic NS
- brain
- spinal cord
Adrenergic receptors types and where they are located
- Alpha 1: peripheral arterioles of smooth muscles
- alpha 2: brainstem, spinal cord
- Beta 1: primarily in the heart
- beta 2: primarily in lungs (bronchial smooth muscle)
Uses of sympathomimetics
- anaphylaxis - epinephrine; fast acting; causes bronchodilation, vasoconstriction
- increases alertness: ADHD, narcolepsy, amphetamines (adderall)
- eyes: increase dilation to reduce itching, or pressure (glaucoma)
- overactive bladder
- incontinence in children and adults
Cardiovascular uses of sympathomimetics
increase blood flow
- heart failure: B1 agonist - increase contractility (positive ionotrope)
decrease blood flow or increase blood pressure
- hemorrhage or spinal shock/hypotensive emergency: alpha 1 agonist
- causes vasoconstriction
Respiratory uses of sympathomimetics
- reduce nasal congestion: alpha agonist to promote vasoconstriction so you are not as stuffy
- reduce bronchoconstriction: beta agonist
- ei: asthma, COPD, short acting for attacks and long acting for prevention often taken by inhaler
Adverse effects of sympathomimetics
- too much stimulation can cause too much of it
- vasoconstriction, heart attack (due to increase HR), heart arrhythmia, tachycardia
- nervousness, anorexia, insomnia
- pulmonary edema or hemorrhage
- hypertension
- hyperglycemia (increase in cortisol and gluconeogeneis)
side affects of alpha 1 sympathomimetics
- hypertension
- headache
- bradycardia (to try to lower blood pressure)
- it is called reflex bradycardia/cardiac baroreceptor reflex
Side effects of beta agonists (sympathomimetics)
- beta 1 and beta 2
- beta 1: chest pain (less time for heart to get O2 blood), arrhythmias, shortness of breath
- Beta 2: nervousness, restlessness, trembling (associated with bronchodilation)
Mixed sympathomimetics side effects (occur in any of them)
- nervousness
- restlessness
- anxiety
- hypertension
- arrhythmias
- cardiac arrest
Adrenergics/sympathomimetics: rehab considerations
- may allow a pt to participate in therapy
- be cautious with exercise
- precautions: restlessness, increase BP or hR, angina
Sympatholytics:
- adrenergic antagonists
- adrenergic blockers
purpose of sympatholytic drugs
- block action of sympathetic NS
- most drugs target a specific receptor
- ex:
1. alpha anatgonist/alpha blocker
2. beta anatgonist/beta blockers
Alpha blockers
- most are selective to alpha 1 receptors
- designed to reduce vasoconstriction (bring back to normal vasotone through vasodilation)
- uses:
1. treat HTN
2. some used for benign prostatic hypertrophy - end in osin
Side effects from alpha blockers
- reflex tachycardia: BP drops a lot so body compensates by increasing HR
- baroreceptor reflex
- decrease effect (baroreceptor reflex) with alpha selective blocker - orthostatic hypotension
Beta blockers
- used for effect on beta 1 receptors on the heart
- beta 1 selective/cardioselective
- some beta blockers are beta-nonselective (work on both beta 1 and 2)
- beta 2 selective drugs are not clinically useful - not many times you want to cause bronchoconstriction
adverse effects of beta blockers
- blunted exercise response: prevents/decreases HR causing tired and dyspnea
- orthostatic hypotension, dizziness
- heart failure
- depression
- lethargy
uses of beta blockers
- manage hypertension: reduces heart rate and contractility
- can be used to manage angina, reduce the workload of heart
- most beta blockers end in -lol
Rehab relevance to beta blockers
- orthostatic hypotension: frequent BP checks and aquatics with warm pool can cause systemic vasodilation which decreases BP
- bronchoconstriction
- depressed HR/blunted HR response to exercise
Side effects of non-selective beta blockers
- bronchoconstriction
- special concern with existing lung disorders
