Autonomic Nervous System Neurotransmitters Flashcards
What are the 3 neurotransmitters are released by autonomic neurons
Acetylcholine (Ach) and Norepinephrine (NE)
What parts of the ANS are cholinergic neurons
all preganglionic neurons of the sympathetic and parasympathetic divisions, the post ganglionic neurons of the parasympathetic and the post sympathetic neurons of the sympathetic division that go to sweat glands
What parts of the ANS are adrenergic neurons
all post ganglionic neurons of the sympathetic division except the nerve that innervate sweat glands
What are the 2 types of cholinergic receptors and what are they named after
Nicotinic- nicotine mimics Ach at these receptors
Muscarinic– muscarine (a mushroom poison) mimics Ach at these receptors
Is there cross reactivity of nicotine or muscarine receptors
no
Are the effects of Ach long lasting or short acting and why
The effects of Ach are quick b/c acetylcholinesterase quickly deactivates AcH
What is the effect of Ach on nicotinic receptors
depolarization
What is the effect of Ach on muscarine receptors
depolarization or hyperpolarization it depends on the post synaptic cells
What is the Mnemonic that helps you remember what muscarine receptors causes
DUMBELS
defecation urination miosis (eye contraction) bronchoconstriction emesis lacrimation sweating
True or false epinephrine is they only neurotransmitter released by the sympathetic postganglionic neurons
False, NE is released by most sympathetic neurons except for those that go to sweat glands (these release Ach)
What are the types of adrenergic receptors
alpha 1 and 2
beta 1, 2, and 3
What does activation of adrenergic receptors with the subscript 1 typically do
depolarize (excite)
What does activation of adrenergic receptors with the subscript 2 typically do
hyperpolarize (inhibit)
What does activation of adrenergic receptors with the subscript 3 typically do
only to brown adipose tissue so it causes thermogenesis
Why do adrenergic effects last longer than cholinergic effects
NE lingers longer in the synaptic cleft when compared to Ach
What 2 enzymes breakdown NE in the synaptic cleft
monoamine oxidase or catechol-o-methyltransferase
What is an agonist
substance that binds to a receptor and triggers a response
What is an antagonist
substance that binds to a receptor, fails to cause a response and blocks activation by agonist
What is a partial agonist
substance that binds to a receptor and triggers a partial response
What are beta blockers and what do we use them in the medical field for
Blocks the effect of NE/EP on the beta 1 receptors.
Since Beta 1 receptors are located primarily in the the heart it slows down heart rate
What are alpha blockers and what do we use them in the medical field for
Blocks the effect of NE/EP on the alpha 1 receptors.
Since alpha 1 receptors are located in all blood vessels it lowers BP by causing vessels to relax
What is Atropine and how do we use it in the medical field
Anticholinergic drug that block parasympathetic effects
Used preop to reduce secretions. to dilute pupils for eye exams, used as an antidote for chemical warfare agents that inactive acetylcholinesterase
What is Neostigmine and what do we use it for
acetylcholinesterase inhibitor preventing Ach breakdown
-used to treat myasthenia gravis (dz were ach stimulation is impaired)
How do tricyclic antidepressants work
prolong NE in neural synapses
-NE is a feel good drug
How do monoamine oxidase inhibitors work and what do we use them for
inactvates MOA which allows NE to stay longer in synaptic cleft
used for depression
