Lecture 14-16 - Scrogin - Adrenergics (Para vs Symp) Flashcards
The ANS is composed of what 3 parts?
Sympathetic (thoracolumbar)
Parasympathetic (craniosacral)
Enteric Nervous system
Preganglionic cells arise from ___
Intermediolateral cell column of the spinal cord
“Ganglia” give rise to _____
Post-ganglionic cells
What is special about the adrenal gland?
It acts like a ganglion but releases hormone into circulation
Sympathetic: Length of pre-ganglionic vs post-ganglionic
Pre-ganglionic = short Post-ganglionic = long
*Sympathetic starts with “S” and thus “short” is first
Parasympathetic: Length of pre-ganglionic vs post-ganglionic
Pre-ganglionic = long Post-ganglionic = short
ACh is released by
ALL pre-ganglionic fibers
Post-ganglionic parasympathetic
Which fibers release only NE? *and what is the exception?
Post-ganglionic sympathetics
Exception: post-ganglionic sympathetics that innervate sweat glands release ACh
What releases both Epi and NE?
Adrenal Medulla (75% epi, 25% NE)
Pre-ganglionic fibers release
ACh
Post-ganglionic sympathetic fibers release
NE
Exception: post-ganglionic sympathetics that innervate sweat glands release ACh
Post-ganglionic parasympathetic fibers release
ACh
Parasympathetic system innervates what organs?
Eye Heart Bronchioles GI tract Bladder
Sympathetic system innervates which organs?
Same as parasympathetic (*Eye, Heart, Bronchioles, GI tract, Bladder)
AND blood vessels as well as metabolic functions
What is miosis and is it parasympathetic or sympathetic?
Constriction of pupil
Parasympathetic
Describe parasympathetic innervation of the heart
SA node innervation = reduce HR
AV node innervation = slowed conduction
Parasympathetic innervation of bronchioles gives _____
constriction of smooth muscle
Parasympathetic innervation of GI tract gives _____
increased secretions and motility
Parasympathetic innervation of bladder gives _____
Bladder emptying (via activation of detrusor muscle)
Sympathetic innervation of the eye gives _____
mydriasis (dilation) and increased production of aqueous humor by ciliary body
Sympathetic innervation of the heart gives _____
Increased HR (accelerated SA node pacemaker depolarization!)
Faster spontaneous depolarization and lower threshold for activation
Also stimulates greater Ca2+ influx during depolarization which increases contractile force
Sympathetic innervation of bronchioles gives _____
smooth muscle relaxation
Sympathetic innervation of blood vessels gives _____
contraction and relaxation
*depends on receptor
Sympathetic innervation of bladder gives _____
inhibition of emptying via contraction of sphincter
Sympathetic system affects metabolic functions by ___
increasing blood sugar
This enzyme is the rate limiting step in the formation of DOPA
Tyrosine Hydroxylase
Dopamine Beta-Hydroxylase is found where and does what?
Found in synaptic vesicles along with ATP
Converts Dopamine to NE
Describe the release of catecholamines for Adrenergic Neurotransmission
Voltage dependent opening of Ca2+ channels gives increased intracellular Ca2+
Stimulates interaction of SNAREs
Action of neurotransmitter binding depends on what 3 things?
- receptor type
- second messenger system
- machinery of the cell type
MAOI’s are important in ____
the metabolism of catecholamines within the nerve terminal
COMT is important in _____
the metabolism of catecholamines in the circulation
Inhibition of NT reuptake for adrenergic transmission produces ___
potent sympathomimetic effects
To get pupillary constriction, what happens?
Sympathetic tone is withdrawn
What stimulates production of aq humor?
Ciliary epithelium
CO is affected by which receptor(s)? What about TPR?
CO = beta-1 TPR = alpha-1/2 and beta-2
