Peripheral Nervous System "SNS) Flashcards
The Peripheral Nervous system has 2 divisions what are they?
somatic
Autonomic
the somatic nervous system sends Motor (efferent) impulses to where?
Skeletal muscle (does not have a junction as the Autonomic does)
The autonomic nervous system has 2 divisions. what are they?
Sympathetic nervous system (SNS)
Parasympathetic Nervous System (PNS)
Sympathetic PREganglionic nerves generally have _____ lengths. While sympathetic POSTganglionic neurons have ______ lengths
short lengths (preganglionic) Long Lengths ( post ganglionic)
Parasympathetis PREganglionic nerves generally have ______ lengths. While Parasympathetic POSTganglionic neurons have _____ lengths.
Long lengths (preganglionic) Short Lengths (postganglionic)
What is the predominant NT in the periphery
ACh
the Autonomic division is also termed the what division?
Visceral Efferent division
what is a ganglion
A peripheral collection of nerve cell bodies
how can you tell the autonomic division vs the somatic division
the autonomic division has an interruption
is the peripheral nervous system protected by bones?
no
explain the Parasympathetic Nervous system
include Pre and post ganglion fiber, and NT
Long preganglionic
Short Postgangionic
preganglionic and Postgangliionic NT ACH
Cholinergic fibers
What type of fibers are the PNS?
Cholinergic
explain the sympathetic Nervous system
include Pre and post ganglion fiber, and NT
Short pre Long post Pre NT ACh Post NT NE Adrenergic Fibers
What type of fibers are the SNS
Adrenergic
what part of the Autonomic division is the odd ball and why?
Adrenal Medulla
b/c it has to Post ganglionic, the preganglionic fiber goes directly to adrenal medulla and releases ACh then the adrenal medulla releases hormones epi and NE
what does the somatic divisions nerve fiber look like?
1 long uninterrupted neuron
from cord to skeletal muscle
What NT does the Somatic division release at the nerve terminal?
ACh
What receptors are found on tissues innervated by the PNS
Muscarinic
What receptors are found at the autonomic ganglion on the cells of the adrenal medulla and motor end-plate of skeletal muscle?
Nicotinic
receptors can be what 2 types?
ion channels (open) G-protein coupled (2nd messengers)
What type of receptor is the nicotinic
Ion channel
What type of receptor is the muscarinic
G -protein
How would you know if it is a muscarinic receptor?
it’s at the tissue
see page 32 of sweat book to see the receptor sites
look at muscarinic and nicotinic
what is the other name for the SNS
thoracolumbar
The SNS or thoracolumbar system outflow arises from what segments
T-1 to L2 (or L3)
Most sympathetic PREganglionic neurons synapse with the POSTganglionic fibers where?
paravertebral ganglion (side note.. this is right next to the spinal cord thus the reason for SNS has a Short preganglionic and long post
the Sympathetic cardiac accelerators arise from where?
T1-T4
The stellate ganglion is formed by what?
the inferior cervical and first thoracic ganglion
tell me 3 ways to know that it is the SNS
Short pre
Long post
Arise from thoracic or lumbar
In The SNS or thoracolumbar system all PREganglionic fibers pass through what?
white rami
In The SNS or thoracolumbar system some not all POSTganglionic fibers pass through what
Gray ramus
When presynaptic alpha-2 receptors are stimulated by NE or any other drug with alpa-2 receptor agonist activity, the synthesis and release of NE is decreased, this is called what?
Negative feedback system
What is the order of the breakdown of NE
Diffuse away from receptor
Reuptake (80%)
MOA and COMT
what is MOA
MonoAminoOxydase
What is COMT
Catechol-O-Methyl-Transferase
What is the synthesis of NE (end with Epi)
Tyrosine L-Dopa Dopamine Norepinephrine Epinephrine
entry of what ion at the nerve terminal is required to release a NT
Calcium
what are 2 agents that should be avoided in pts taking MAOi’s and why?
indirect acting sympathomimetics (ephedrine)
opioid Meperdine
-B/c both trigger release of NE and may cause HTN crisis
what do the receptors do?
Alpha 1
Vasoconstriction
Increased Inotropy
what do the receptors do?
Alpha 2
Decreased outflow of SNS
Inhibit NE release
Vasodilation
Decreased Chronotropy
what do the receptors do?
Beta 1
Increased Inotropy
Increased Chronotrophy
Increased Dromotropy
what do the receptors do?
Beta 2
Increased Inotropy
Increased Chronotropy
Peripheral Vasodilation
Bronchodilation
What does Alpha 2 receptors do for pain
stimulation of Alpha-2 receptors in the substantial gelatinosa of the spinal cord promotes analgesia
