Unit 2 - Autonomics I Flashcards
length of fibers in the sympathetic division
thoracocolumbar
- preganglionic are short
- postganglionic are long
length of fibers in parasympathetic division
scraniosacral
- preganglionic are long
- postganglionic are short
what are generalizations you can make about:
- all preganglionic
- postganglionic parasympathetic nt
- postganglionic sympathetic nt
- pregang: ALL use ACh to nicotinic receptors
- postgang para: ALL use ACh with little/no branching (1:1 chlinergic fibers) to muscarinic ACh receptors
- postgang symp: NOT ALL use NE with more branching (1:20 adrenergic fibers)
what are the different nt postganglionic sympathetic can use?
- NE to alpha/beta (cardiac and smooth muscle, gland, nerve terminals) –> classical
- ACh to muscarinic (sweat glands)
- D to D1 (renal vascular smooth muscle)
- ACh to neurologic nicotinic (chromaffin cells)
what are skeletal muscle ganglions?
straight from spinal cord via voluntary motor nerve to muscarnic nicotinic ACh
describe ACh
primary nt at ANS ganglia, somatic neuromuscular junction, and at parasympathetic postganglionic nerve endings
- primary excitatory transmitter to smooth muscle and secretory cells in ENS
- major neuron-to-neuron (“ganglionic”) transmitter in ENS
describe norepineNE
primary transmitter at most sympathetic postganglionic nerve endings
how is neurotransmission at cholinergic VS noradrenergic nerve terminals different?
in terms of their handling after release (esp. drugs inhibiting synthesis, storage, and release)
- for ACh, non-specific and not generally useful (except botulinum toxin)
- for NE, specific and useful (b/c release blockers for HTN, uptake blockers, or releasers as stimulants)
what are the best drug targets? why?
target tissue receptors
-allow for selectivity
how do subunit arrangement and molecular structure of nictonic ACh receptors differ?
are all different in regards to muscarinic, neuronal, etc.
are Nn ACh receptors good drug targets? response time?
poor drug targets, but fast responses
are alpha/beta adrenergic receptors good drug targets? response time?
good drug targets, but slow responses to NE (different tissues express different receptors)
are M1-M5 ACh adrenergic receptors good drug targets? response time?
good drug targets, but slow responses (different tissues express different receptors)
what are the steps of response for M1/3/5
Gq –> PLC+ –> DAG increases + IP3 (Ca) increases
like alpha1
what are the steps of response for M2/4
Gi –> AC- –> cAMP (decreases)
Gi –> Kchan+ –> hyperpolarization
(like alpha2)
