Autonomic 1 Flashcards
blood brain barrier
- consists of
- function
- problem with treatment
- endothelial cells
- pericytes
- protects the brain from harmful substances
- needs to be small, lipophillic, uncharged to get through
- tough to pass with drugs to treat problems in the brain
preganglion fibers for symp and para
- symp are short
- para are long
effects of the parasympathetic nervous system
- constriction of pupils
- constriction of bronchi
- incresaed detrusor muscle activity
- reduced heart rate
- increased tear and saliva production
- increased GI peristalsis
role of the adrenal glands
- release epinephrine systemically
- is the reason why the sympathetic nervous system predominates in humans
resopnse to sympathetic innervations
- dialtion of pupils
- dilation of bronchi
- reduced detrusor muscle activity
- increased heart rate
- constriction of blood vessels
- increased blood pressure
- reduced GI preistalsis
where in the neuron is acetycholine found
- 50% in the vesicle
- 50% in the cytoplasm
acetylcholinesterase
-degrades Ach in the synaptic cleft, terminating its effect
where are muscarinic and nictonic receptors found
- muscarinic at target organs
- nictonic at the ganglia and at the neuromuscular junction
atropene
-anticholinergic medication
symptoms of Ach muscarinic antagonism
- dry mouth
- blurred vision
- urinary retention
- constipation
- tachycardia
- impaired cognition
NMBs can work by two mechanisms
- blocking Ach receptors, causing flaccid paralysis and a complete lack of stimulation
- overstimulating Ach receptors leading to spastic paralysis
cholinomimetics act by two mechanisms
- as an agonist to the receptor
- inhibiting acetylcholinestesterase
bethanecol
-direct acting agonist of GI motility
edrophoneum
- used to diagnose myasthenia gravis
- cholinesterase
- short acting so it does not propogate spastic paralysis for too long if that is in fact the problem
physostigmine
- an Achase that can cross the BBB
- can be used to treat overdoses with anticholinergic medications that have large volumes of distribution
organophosphates
- where is it found
- used to do what
- mechanism
- this is the active ingredient in most insecticide products
- used to induce spastic paralysis
- noncompetitive achase inhibitor
precursor of catecholamines
-tyrosine
monoamine oxidase
-primary metabolism for the degradation of monoamine containing NT’s (NE, E, dopamin, serotonin)
signal termination of catecholamines
-taken back up into the presynaptic neuron
levodopa
- converted by decarboxylase enzymes into dopamine
- helpful in treating parkinsons
- given with carbidopa in order to maximize entry into the brain
methyldopa
- reduces the synthesis and release of NE
- serves as an antihypertensive therapy due to its reduction of stimulation of the alpha 1 receptors
- sympatholytic
clonidine
-alpha 2 agonist
causes decreased release of NE
-used to reduce blood pressure
amytriptyline
- tricyclic antidepressant
- blocks both serotonin and NE
- nonselective
fluoxetine
- prozac
- selective reuptake inhibitor of serotonin
tricyclic antidepressants (fluoxetine and amytryptiline) should be avoided when
- a patient is taking clonidine for their blood pressure
- these medications will have opposing effects
monoamine oxidase inhibitors
-what should you avoid
- sometimes used to treat depression
- should avoid tyramines which displace catecholamines, this adds to the sympathomimetic effect
