Flashcards in AUTONOMIC PHARMACOLOGY Deck (77):
1
T1 - T12
L1 - L5
Sympathetic/Thoracolumbar
2
CN 3,7,9,10
S2-S4
Parasympathetic
(Craniosacral)
3
SYMPATHETIC (SANS)
Preganglionic fibers originate from
Thoracic (T1 -T12) segments of the cord
Lumbar (L1 -L5) segments of the cord
4
PARASYMPATHETIC (PANS)
Preganglionic motor fibers originate from
Cranial nerve nuclei III, VII, IX and X
Sacral segments (S2-S4)
5
Preganglionic fibers are short and the
postganglionic fibers are long
SYMPATHETIC
6
Few (prevertebral) on the anterior aspect of the
aorta
SYMPATHETIC
7
Most of the ganglia are located in 2 paravertebral
chains that lie along the spinal cord
SYMPATHETIC
8
Most of the ganglia are located in the organs
innervated, most distant from the spinal cord
PARASYMPATHETIC
9
Preganglionic fibers are long and the
postganglionic fibers are short
PARASYMPATHETIC
10
NEUROTRANSMITTERS (NTAs)
4 FEATURES
1. Synthesis
2. Storage
3. Release
4. Termination of action
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NEUROTRANSMITTERS
TERMINATION OF ACTION
By metabolism
-Monoamine oxidase (MAO)
-Cathecol-o-methly transferase (COMT)
Diffuse away from the synaptic cleft and get metabolized elsewhere
12
A nerve ending that releases acetylcholine as
the primary transmitter
Also a synapse in which acetylcholine is the
primary transmitter
CHOLINERGIC
13
A nerve ending that releases norepinephrine as
the primary transmitter
Also a synapse in which norepinephrine is the
primary transmitter
ADRENERGIC
14
All preganglionic fibers are
cholinergic
15
All postganglionic parasympathetic fibers are
cholinergic
16
A few postganglionic sympathetic fibers are
cholinergic
17
Most postganglionic sympathetic fibers are
adrenergic
18
Exception: Postganglionic sympathetic fibers
are
cholinergic
19
Adrenal cortex and medulla
Ductless gland that functions as a ganglion
Postganglionic fibers are cholinergic
ADRENAL GLAND
20
Inhibits transport/synthesis of ACh into the cell
HEMICHOLINIUM
21
Inhibits storage of ACh into the vesicle
VESAMICOL
22
Inhibits the release of ACh
BOTULINUM TOXIN
23
These drugs (Hemicholinium, vesamicol, botulinum toxin) are not very useful for systemic therapy
because their
effects are not sufficiently selective
24
Inhibits the synthesis of NE
METYROSINE
25
Inhibits the storage of NE
RESERPINE
26
These drugs (METYROSINE, RESERPINE, GUANETHEDINE, MAO I) have been used in several diseases because
they block sympathetic but not parasympathetic functions
27
Inhibits release of NE
GUANETHEDINE
28
Inhibits metabolism of NE
MAO I
29
Other transmitter molecules in addition to the
primary agents (ACh or NE)
Contained in many autonomic nerves
Localized in the same vesicle as the primary
transmitter or in a separate population of vesicles
Involved in the modulation of synaptic
transmission
COTRANSMITTERS
30
ATP
Enkephalins
VIP
Neuropeptide Y
Substance P
Somatostatin
Neurotensin
COTRANSMITTERS
31
RECEPTOR CHARACTERISTICS
Also referred as cholinergic receptors
Respond to ACh and its analogs
A. CHOLINOCEPTORS
32
A. CHOLINOCEPTORS
Subdivided into
1. MUSCARINIC receptors
2. NICOTINIC receptors
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A. CHOLINOCEPTORS
Respond to muscarine (an alkaloid)
Respond to ACh
Mimics the effects of parasympathetic
G-protein coupled
1. MUSCARINIC receptors
34
Located primarily on autonomic effector cells
Heart
Blood vessels
Smooth muscles
Presynaptic nerve terminals
Exocrine glands
1. MUSCARINIC receptors
35
3 subtypes of muscarinic receptors are important in peripheral autonomic
transmission
M1-nerve endings
M2-heart, some nerve endings
M3-effector cells, smooth muscle, exocrine
glands, endothelium
36
A. CHOLINOCEPTORS
2. NICOTINIC receptors
Respond to ACh
Respond to nicotine (another ACh mimic)
Do not respond to muscarine
Ligand-gated
37
A. CHOLINOCEPTORS
2. NICOTINIC receptors
2 major subtypes:
Nn-neuronal (ANS ganglia)
Nm-neuromuscular endplate (skeletal muscle)
38
TYPE OF CHOLINOCEPTORS
Nerve endings
G-coupled
Increase IP3
M1
39
TYPE OF CHOLINOCEPTORS
Heart, some nerve endings
G-coupled
Decrease cAMP,
activates K+ channel
M2
40
TYPE OF CHOLINOCEPTORS
Effector cells, smooth
muscle, glands, endothelium
G-coupled
Increase IP3
M3
41
TYPE OF CHOLINOCEPTORS
ANS ganglia
Ion channel
Depolarizes, evokes
action potential
Nn
42
TYPE OF CHOLINOCEPTORS
Neuromuscular end plates
Ion channel
Depolarizes, evokes
action potential
Nm
43
RECEPTOR CHARACTERISTICS
Also referred as adrenergic receptors
Respond to NE
G-protein coupled
B. ADRENOCEPTORS
44
B. ADRENOCEPTORS
Subdivided into
1. ALPHA receptors
2. BETA receptors
45
ALPHA receptors
Located in
Blood vessels
Presynaptic nerve terminals
Blood platelets
Fat cells (lipocytes)
Neurons in the brain
46
ALPHA receptors
2 subtypes
effector tissues, smooth muscles, glands
ALPHA1-
47
ALPHA receptors
2 subtypes
nerve endings, some smooth
muscles
ALPHA2-
48
ADRENOCEPTORS
2. BETA receptors
Located on
Most types of smooth muscle
Cardiac muscle
Some presynaptic nerve terminal
Lipocytes
Brain
49
BETA receptors
3 major subtypes
BETA1-heart and kidney
BETA2-lungs, uterus, liver, heart
BETA3-fat or adipose tissue
50
Type of Adrenoceptor
Effector tissues, smooth muscle,glands
G-
Increase IP3
Increase Ca2+ ,causes contraction, secretion
Alpha1
51
Type of Adrenoceptor
Nerve endings, some smooth muscle
G- Decrease
cAMP
Decrease transmitter release, causes
contraction
Alpha2
52
Type of Adrenoceptor
Cardiac muscle, kidney
G-
Increase cAMP
Increase heart rate, force, increase renin release
Beta1
53
Type of Adrenoceptor
Lungs, uterus, heart
G-
Increase cAMP
Relax smooth muscle,
increase glycogenolysis,
increase HR, force
Beta2
54
Type of Adrenoceptor
Adipose cells
G-
Increase cAMP
Increase lipolysis
Beta 3
55
Predominant state in any situation
CENTRAL INTEGRATION
56
CENTRAL INTEGRATION
Ergotrophic (energy expenditure)
”Fight or flight” response
SYMPATHETIC
57
CENTRAL INTEGRATION
Tropotrophic (energy saving)
Leading to growth
”Rest and digest
PARASYMPATHETIC
58
Principle of negative feedback control
Alpha receptors located on noradrenergic
terminals which are activated by NE and other
similar molecules
Activation diminishes further the release of NE
from these nerve endings
PRESYNAPTIC REGULATION
59
PRESYNAPTIC REGULATION
Presynaptic receptors that respond to
transmitter substances released by the
nerve endings and thereby regulate its
release
AUTORECEPTORS
60
Up- and down-regulation are known to
occur in response to decreased or
increased activation of the receptors
Up regulation (agonist)
Down regulation (antagonist)
POSTSYNAPTIC REGULATION
61
Transmission involves different mechanisms
in different segments of the ANS
Some drugs produce highly specific effects
Others drugs are much less selective in their
actions
PHARMACOLOGIC MODIFICATION OF
AUTONOMIC FUNCTION
62
PHARMACOLOGIC MODIFICATION OF
AUTONOMIC FUNCTION
Drug that block action potential
Very nonselective
Act on the process that is common to all
neurons
LOCAL ANESTHETICS
63
PHARMACOLOGIC MODIFICATION OF
AUTONOMIC FUNCTION
Drugs that act on the biochemical processes
involved in transmitter synthesis and storage
are more ----
selective
64
Promote the release of NE
Effect is sympathetic
TYRAMINE AND AMPHETAMINE
65
Blocks uptake of ACh
Slows synthesis of ACh
HEMICHOLINIUM
66
Prevents storage of ACh
VESAMICOL
67
Prevents release ACh
BOTULINUM TOXIN
68
Binds alpha receptors
Causes activation (agonist)
NOREPHINEPHRINE
69
Binds alpha receptors
Prevents activation (antagonist)
PHENTOLAMINE
70
Binds beta receptors
Activates adenyl cyclase (agonist)
ISOPROTERENOL
71
Binds to beta receptors
Prevents activation (antagonist)
PROPRANOLOL
72
Causes skeletal muscle contraction
(agonist)
NICOTINE
73
Prevents skeletal muscle contraction
(antagonist)
TUBOCURARINE
74
Binds muscarinic receptors
Activates (agonist)
BETANECHOL
75
Binds muscarinic recepto
Prevents activation
ATROPINE
76
Inhibits enzyme acetylcholinesterase
Prolongs and intensifies transmitter action
NEOSTIGMINE
77