4.1 Flashcards
How many nerves are in an ANS pathway?
2
What neurotransmitter is used at ganglia? What kind of receptor?
ACh
Nicotinic
What is the other name for the SNS? PNS?
SNS- Thoracolumbar
PNS- Craniosacral
Describe the nerve fibers of the SNS
Short preganglionic
Long postganglionic
Describe the nerve fibers of the PNS
Long preganglionic
Short postganglionic
Where are the neurons for the ENS?
ENS= enteric nervous system
In walls of GI system
What is the myenteric plexus? What does it regulate?
The major nerve supply of the GI tract, regulates motility
What is the submucosal plexus?
Part of ENS- regulates secretions
What is the cholinergic neurotransmitter? Where found?
ACh
All preganglionic efferent and somatic. Most PNS postganglionic
What is the noradrenergic neurotransmitter? Where found?
NorEpi
Postganglionic SNS
What are dopaminergic neurotransmitters? Where found?
Dopamine
peripheral SNS
What are examples of peptide neurotransmitters?
neurotensin, LH, substance P
Endogenously released
Describe ACh synthesis
Acetyl Coa+ Choline group –> Ach
Once Ach is synthesized, pumped into vesicles by VAT (vesicle associate transporter)
Stored in vesicle until released into neuro cleft
In ACh synthesis, what are ChAT, VAT, SNAP, and VAMP?
ChAT = Choline Acetyltransferase VAT = Vesicle Associate Transporter SNAP = synaptosome-assoc protein VAMP = vesicle-assoc membr protein
How does botulism toxin work?
Blocks ACh release, leads to paralysis
How does black widow venom work?
Stimulates ACh release to depletion, Contraction to paralysis (no medical use yet)
What are the precursor molecules for dopamine?
Tyrosine + Dopa
What limits the rate of production of dopamine?
Dopa
In dopamine production, what do VMAT and NET do?
VMAT puts dopamine into vesicles
NET- reuptake
What happens if too much NE in the NMJ?
SNS-type symptoms- jittery, jumpy, triggers adrenergic sys
What is Reserpine used for? Mechanism?
old, d/c’d drug (was used for HTN, psychosis) inhibits VMAT, the enzyme that fills vesicles with dopamine
So, vesicles don’t fill, decreased storage of dopamine, because leaks out of cell, this decreases NE, low BP
The problem: will have some adrenergic (sympathtic) response using this drug (before low BP, high BP)
What is the mechanism of tyramine and amphetamines?
similar to amphetamines, ephedrine (extracted from a chinese herb)
Inhibits a transporter eventually displacing NE from vesicle
NE pushed out, diffuse into neural cleft, causing a sympathetic response
ETOH + these meds massive dump of neurotransmitters badness
What is a cotransmitter? Example? What do they do?
Substances release in addition to primary transmitter (i.e. neuropeptides)
Some in same vesicles or separate vesicle
Provide faster or slower action to supplement effects of primary transmitter
Provide feedback inhibition
What are the non-adrenergic, non-cholinergic (NANC) neurotransmitters?
Peptides NO (nitrous oxide) Substance P Cholecystokikin Serotonin
