Autonomic Pharmacology Flashcards
Nervous system is divided into what 2 divisions?
What do each control?
Somatic:
consciously controlled functions such as movement, respiration, and posture.
Autonomic:
concerned primarily with visceral functions
that are necessary for life such as cardiac
output, blood flow to various organs, digestion, etc
the ANS divides into what 2 major portions?
- Sympathetic (thoracolumbar) division
- Parasympathetic (craniosacral) division
Somatic nervous system has what type of neuron?
how many?
cholinergic (ACh)
1 myelinated coming fron CNS
How are the neurons used in the sympathetic pathway of the ANS?
what about the parasympathetic pathway?
they are 2 neurons coming out and working together, and are Norepinephrine
they are 2 neurons as well and are cholinergic
What are the three major differences in the ANS and SNS?
- Effectors: the target organ
- Efferent pathways
- Target organ responses
what is the effectors of the Somatic Nervous System?
are skeletal muscles
what are the effectors of the ANS?
are cardiac muscle, smooth muscle, and glands
How are the neurons of the somatic nervous system?Motor neurons of the somatic nervous system extend from where to where? what do they lack?
Myelinated thick axons
from the CNS to the effector
lacks ganglia
ANS neurons are how? how are each?
two-neuron chain:
preganglionic: has a thin myelinated axon
postganglionic: unmyelinated neuron which extends to an effector organ via the postganglionic axon
what neurotransmitter do somatic neurons release from their synapses?
what effect does this have on target organs?
Cholinergic (ACh)
excitatory
what neurotrasmitter do ANS pre-ganglionic neurons release?
what effect will this neurotransmitter have on target organs?
what neurotrasmitter do ANS post-ganglionic neurons release?
what effect will this neurotransmitter have on target organs?
ACh
excitatory
norepinephrine or ACh
inhibition
what are the major neurotrasmitters in the ANS?
- Acetyl choline
- Norepinephrine (Noradrenaline)
- Epinephrine(Adrenaline)
- Dopamine
- Several co transmitters
what are the 2 types of nerve fibers in the ANS based on neurotrasmitters?
Cholinergic fibers –>ACh
Adrenergic/noradrenergic fibers –> epinephrine/norepinephrine
what are 3 characteristics of Cholinergic nerve fibers?
- All Preganglionic fibers in both Sympathetic and parasympathetic nerves
- All parasympathetic postganglionic
- Few sympathetic postganglionic fibers
what is 1 characteristic of adrenergic nerve fibers?
Are most of the postganglionic sympathetic fibers
Based on the type of neurotransmitter there are Two types of receptors, what are these? what are the examples of each?
- Cholinergic receptors:
- Muscarinic: M1/2/3/4/5 –> all are g-protein coupled
- Nicotinic: Nm and Nn –> are ion channel mediated
- Adrenergic receptors: alpha 1/2 and beta 1/2/3 –> all are g-protein coupled
What are the consequences of Cholinergic receptor activation in Heart?
Reduces HR, FOC, CO
What are the consequences of Cholinergic receptor activation in blood vessels?
Vasodilatation, ↓low BP
What are the consequences of Cholinergic receptor activation in smooth muscle?
Contraction..bronchospasm Diarrhea, Urination
What are the consequences of Cholinergic receptor activation in sphincter?
relaxation
What are the consequences of Cholinergic receptor activation in pupil?
miosis
What are the consequences of Cholinergic receptor activation in glands?
Salivation, sweating, gastric acid
What are the consequences of adrenergic receptor activation in heart?
blood vessels?
smooth muscle?
sphincters?
pupil?
glands?
Increases HR, FOC, CO
Vasoconstriction, ↑ BP
Relaxation: Bronchodilation, constipation, Urinary retention
contraction
myadriasis
What receptors utilize Gq?
M1
M3
Alpha 1
receptors that utilize Gq will use what effector enzyme?
it will stimulate Phospholipase C
receptors that utilize Gq will utilize what 2nd messengers?
IP3 and DAG
what receptors will use Gi from G protein?
alpha 2 and M2
alpha 2 and M 2 will do what by using Gi?
inhibit Adenylyl cyclase and therefore cAMP
what receptors utilize Gs G protein subunit?
beta 1, beta 2, beta 3
Gs will stimulate what?
adenylyl cyclase and increase cAMP
M1 receptors are found where?
M2 receptors are found where?
M3 receptors are found where?
Nmreceptors are found where?
neurons
heart
smooth muscle and glands or pupils and ciliary muscle
skeletal muscle end plate
M2 receptos when engaged will result in what effect?
reduce heart rate
M3 receptors of smooth muscle and glands, when engaged will result in what effect?
contraction except in blood vessels:
- diarrhea, bronchoconstriction, urination,
increase in secretion:
- salivation, stomach acid, sweating, lacrimation
M3 receptors of pupils and ciliary muscle, when engaged will result in what effect?
Contraction
- Miosis, increased flow of aqueous humor
where are alpha 1 receptors found?
blood vessels, iris, smooth muscle
where are alpha 2 receptors found?
presynaptic neurons
where are beta 1 receptors found?
heart and juxtaglomerular aparatus
where are beta 2 receptors found?
smooth muscles
where are beta 3 receptors found?
fat tissue
when alpha 1 receptros are engaged they will cause what in:
- blood vessel?
- pupils?
- smooth muscles?
blood vessel: Vasoconstriction
Pupil: Mydriasis
Smooth muscle: sphincter contraction
- Constipation and Urinary retention
when alpha 2 receptors are engaged they will cause what in:
presynaptic neurons, heart and blood vessels
presynaptic neurons: reduced release of nor-epinephrine
- bradycardia, hypotension
when beta 1 receptors are engaged they will cause what?
heart: contraction and increased heart rate
JGA: increase renin release
when beta 2 receptors are engaged they will cause what?
smooth muscle: Relaxation
- so bronchodilation, urinary retention, constipation, uterus relaxation
when beta 3 receptors are engaged they will cause what?
fat tissue: lipolysis
what receptor can we find in the adrenal medulla?
If engaged, what will it do?
Nn receptors
secretion of epinephrine and nor-epinephrine
what receptors do we find in the autonomic ganglia?
Nn receptors
and
Alpha 2
what are the Five key features of neurotransmission?
- synthesis
- storage
- Release
- activation of receptors
- termination of action/ reuptake
the rate limiting step of Ach synthesis depends on what?
reuptake of choline
what is the rate limiting step for catecholamine synthesis?
tyrosine hydroxylase
what stops the cholinergic neurotransmission?
acteylcholine esterase
what terminates the adrenergic neurotrasmission?
by adrenergic reuptake
what enzyme is important for the conversion of tyrosine to DOPA?
tyrosine hydroxylase
what drug can inhibit tyrosine hydroxylase?
metyrosine
what drug can inhibit dopamine and serotonin to insert into the vesicles affecting VMAT?
what can it cause?
what was it used for before?
reserpine
depression
controlling high blood pressure
what drugs affect the release of epinephrine?
why was this drug removed from market?
bretylium and guanethidine
led to tachychardia
what will cocaine and tricyclic antidepressants do?
inhibit the re-uptake of norepinephrine
