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The Structure of the Nervous
System: Parasympathetic
System
Created @January 21, 2025 3:22 PM
Class Principles to Neuroscience and Pharmacology
Postganglionic Neurotransmitters
Parasympathetic:
Release Ach for individual organs
Local effect
‘Rest and digest’
Sympathetic
NA release
Emergency function
Fight or flight
Far-reaching effects
Parasympathomimetic
Copies or promotes muscarinic actions of Ach
Can also block NA
Sympathomimetic
Copy or promote NA actions
Inhibit muscarinic actions of Ach
The Structure of the Nervous System: Parasympathetic System 1
, Ach- Messenger, packaged in the vesicle, Nicotinic and Muscarinic receptors are
activated by specifics.
Nicotinic Receptors
Pentameric- 5 protein subunits
Ionotropic
Ligand-gated ion channel
Channel opens and positively charged ions flood through the channel
2 molecules of Ach required for receptor activation
Always causes excitation
Muscarinic
5 receptors
Binding domains
M1-3-5 coupled to GQ protein, always excitation
M2-M4 coupled to different intracellular pathway for inhibition
Different organs express different types of receptors
M1 Receptor
Found in gastric parietal cells
causes depolarisation
increases amount of gastric acid being secreted
Agonists include pilocarpine
The Structure of the Nervous System: Parasympathetic System 2
The Structure of the Nervous
System: Parasympathetic
System
Created @January 21, 2025 3:22 PM
Class Principles to Neuroscience and Pharmacology
Postganglionic Neurotransmitters
Parasympathetic:
Release Ach for individual organs
Local effect
‘Rest and digest’
Sympathetic
NA release
Emergency function
Fight or flight
Far-reaching effects
Parasympathomimetic
Copies or promotes muscarinic actions of Ach
Can also block NA
Sympathomimetic
Copy or promote NA actions
Inhibit muscarinic actions of Ach
The Structure of the Nervous System: Parasympathetic System 1
, Ach- Messenger, packaged in the vesicle, Nicotinic and Muscarinic receptors are
activated by specifics.
Nicotinic Receptors
Pentameric- 5 protein subunits
Ionotropic
Ligand-gated ion channel
Channel opens and positively charged ions flood through the channel
2 molecules of Ach required for receptor activation
Always causes excitation
Muscarinic
5 receptors
Binding domains
M1-3-5 coupled to GQ protein, always excitation
M2-M4 coupled to different intracellular pathway for inhibition
Different organs express different types of receptors
M1 Receptor
Found in gastric parietal cells
causes depolarisation
increases amount of gastric acid being secreted
Agonists include pilocarpine
The Structure of the Nervous System: Parasympathetic System 2
