Pharmacology of Autonomic Nervous System Drugs.

1. Drugs Acting on
Para-Sympathetic Nervous System
&
Sympathetic Nervous System
By: Dr. Baqir Raza Naqvi
AutonomicNervousSystem
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2. Organization of ANS
(Autonomic Nervous System)
its subdivisions and
innervations
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3. Nervous system
1. Peripheral
Nervous system
2. Central
Nervous
system
Brain
Spinal cord
Consists of nerves which lie outside
of the brain and spinal cord
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4. 4

5. 5

6. 6

7. A. Somatic Nervous System
Consists of single myelinated neuron, which originating
from CNS and terminates directly into skeletal Muscles
without mediation of ganglia.
It is voluntary system
Whereas autonomic is in-voluntary
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8. B. Autonomic Nervous System
 Controls and regulates normal daily vital body
functions
 Involuntary and Consists of ;
Sympathetic N.S
Parasympathetic N.S
Enteric N.S
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9. 9

10. 10

11. 11
General comparison b/w SNS & PSNS

12. 12
General comparison b/w SNS & PSNS

13. 1. Sympathetic N.S
Preganglionic neurons comes from thoracic
and lumber region of spinal cord
Preganglionic neurons are short as compare
to postganglionic fibers
It involves in fight and flight
Neurotransmitters include adrenaline and
nor adrenaline (Catecholamine's)
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14. 2. Parasympathetic N.S
Parasympathetic preganglionic fibers arise from
cranium (cranial nerves III, VII, IX and X) and from
sacral nerves in spinal cord
Involved in maintenance homeostasis
Preganglionic fibers are longer as compared to post
ganglionic fibers
Acetylcholine is principal neurotransmitter
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15. Functions of Parasympathetic Nervous
System
Eye: Contraction of Iris sphincter muscle
(pupil contract) Contract of ciliary muscle
(lens accommodate for near vision)
Trachea & Bronchioles: Constriction,
increased secretions
Ureters & Bladder: Contraction of
detrusor; relaxation of trigon sphincters
Genitalia (Male): Stimulate erection
Lacrimal Glands: Stimulate tears
Salivary glands: Copious, watery
secretion
Eye: Contract of Iris radial muscle (Pupil
dilates)
Trachea & Bronchioles: Dilation
Adrenal Medulla: Secrete epinepherine
& norepinephrine
Kidney: secrete renin
Ureters & Bladder: Relaxation of
detrusor
Contract Trigone & Sphincter
Genitalia: Stimulate ejaculation
Functions of Sympathetic Nervous
System
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16. 16
General comparison b/w SNS & PSNS

17. 3. Enteric Nervous System
It is collection of nerve fibers that innervate the
GI tract, pancreas, & gallbladder
It is also known as "Brain of the gut”
It functions independently of CNS
It controls the motility, exocrine and endocrine
secretions and microcirculation of gastrointestinal tract.
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18. Various Neurotransmitters
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19. 19

20. Drugs Acting on
Para - Sympathetic
Nervous System
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21. Synthesis of Acetylcholine
(Neurotransmitter of Parasympathetic N.S)
• Choline enters the cholinergic neuron by carrier-
mediated transport, where it reacts with acetyl-
CoA with the help of choline acetyltransferase
(ChAT) to form ACh.
• The ACh is then stored in storage vesicles.
• It is released into the synaptic cleft, when an
action potential reaches the nerve terminals.
• Released ACh interacts with cholinergic
receptors on effector cell and activates them.
• In the synaptic cleft, the ACh is rapidly
hydrolyzed by acetyl cholinesterase (AChE)
enzyme. 21

22. 22
Synthesis of Acetylcholine
(Neurotransmitter of Parasympathetic N.S)

23. Cholinergic Receptors in Body
(Muscarinic & Nicotinic Receptors)
1. Muscarinic
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24. 2. Nicotinic
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25. 1.Para-Sympathomimetic Drugs
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26. Therapeutic Uses of Cholinergic Drugs
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27. 27

28. 2. Para-Sympatholytic Drugs
Or Anti Cholinergic drugs
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29. Therapeutic Uses of Anti- Cholinergic Drugs
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30. 30

31. Drugs Acting on
Sympathetic
Nervous System
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32. Synthesis of Catecholamine's (NA)
Neurotransmitter of Sympathetic N.S)
• It begins with the amino acid tyrosine,
which is transported into the adrenergic
neuron by active transport.
• In the neuronal cytosol, tyrosine is
converted to DOPA by tyrosine hydroxylase
and DOPA to dopamine (DA) by DOPA
decarboxylase.
• Dopamine enters the storage vesicles of the
nerve terminal by active transport, where it
is converted to NA (Norepinephrine) by the
enzyme dopamine hydroxylase the NA
formed gets stored in the vesicles.
• In the adrenal medulla, NA is further
converted to adrenaline by N-
methyltransferase.
• Small quantities of NA are released
continuously into the synaptic cleft and
large quantities during nerve stimulation.
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33. 33
Synthesis of Catecholamine's (NA)
Neurotransmitter of Sympathetic N.S)

34. 34

35. Adrenergic Receptors in Body
(Alpha & Beta Receptors)
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36. 36

37. 37

38. 38
(dilation of pupil)

39. 39

40. 1. Sympathomimetic Drugs
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41. Sympathomimetic Drugs (Cont.)
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42. 2. Sympatholytic Drugs
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43. 1.
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44. 2.
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45. Thank you !
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