Nervous System I

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Nervous System I

• Nervous Tissue
• Neurophysiology

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Homeostasis Controls
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Nervous System Function
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Neuron Development
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Chemical Stimulus for Neuron Development
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Neural TubeFormation and Closure
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Embryonic Development of Neural Tube to form CNS
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Nervous System Divisions

• Physiological
• Sensory
• Afferent
• Types
• Somatic
• Special
• Visceral
• Motor
• Efferent
• Types
• Somatic
• Autonomic

• Anatomical
• CNS
• Brain
• Spinal Cord
• PNS
• Cranial Nerves
• Spinal Nerves

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Neural Tissue Neurons
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Neuronal Processes

• Dendrites
• Cell Body
• Axon Hillock
• Axon
• Telodendria
• Synaptic Knob

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Neuron Structure
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Neuron Cell Body Soma
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Neuron Organelles
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Nucleolus
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Nissl Bodies
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Nuclei and Ganglia
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Tracts and Nerves
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Neuron Types
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Multipolar
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Multipolar Neuron Variations
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Brain Neurons
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Mulitpolar Neuron Histology
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Bipolar Neurons
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Bipolar Neuron Histology
Olfactory epithelium
Retina
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Pseudounipolar Neuron
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Pseudounipolar Neuron Histo
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Other Neurons

• Interneurons
• Spinal Cord Pathways
• Association Neurons
• Brain pathways

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Summary of Neuron Types
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Neural Tissue Neuroglia
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(No Transcript)
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CNS Neuroglia
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Astrocytes CNS
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Oligodendrocytes CNS
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Microglia CNS
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Ependymal Cells CNS
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CNS Neuroglia Summary
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PNS Neuroglia
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Satellite Cells PNS
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Schwann Cells PNS
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Schwann Cell Function
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Myelination in CNS and PNS
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Formation of Myelin Sheath
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Myelination
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Myelination and Nodes
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Nerve Fibers
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Non-myelinated Myelinated
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Generalized Multipolar Myelinated Motor Neuron
Dendrites Cell body Axon Hillock Axon and Axon
Collaterals With myelin Telodendria Synaptic
Knobs
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Telodendria and Synaptic Knob
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Effects at a Synapse

• Transmit signals
• Block signals
• Change frequency
• Single
• Repetitive
• Integrate

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Synapse Types

• Anatomy
• Axodendritic
• Axosomatic
• Axoaxonic
• Physiology
• Electrical
• Gap junctions
• Ion movement
• Bi-directional
• Chemical
• Neurotransmitters
• Uni-directional

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Junctions
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Cell Structures
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Plasma Membrane Proteins
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Na / K Pump
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Na/K ATP Protein Pump
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Another Use of Na/K pump
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Ion Channels

• Ion Channels
• Specific to ion
• Transmembrane
• Types
• Gated
• Chemical
• Voltage
• Mechanical
• Leak

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Gated Ion Channels
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Ion Channels in Action

• RMP
• Na/K pump
• Electrical potential
• Ion concentrations
• Value
• -65mV
• -90mV

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Neuron Physiology Terms

• Hyperpolarization
• RMP
• Depolarization
• Threshold
• Action Potential
• Repolarization
• Refractory Period
• After-Hyperpolarization

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Neurophysiology Graph ID
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Resting Membrane Potential
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RMP measured
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Neuron Stimulus
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Voltage Regulated Channels
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Chemically Regulated Channels
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Nerve Impulses

• Graded Potentials
• Inhibitory
• Hyperpolarization
• K out
• Excitatory
• Depolarization
• Na in
• Threshold
• Na K
• Action Potential
• Continuous
• Saltatory
• Repolarization

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Ohms Law

• V I x R
• I V / R
• Current Voltage / Resistance
• Flow Pressure / Resistance
• Neurons
• Blood
• Respiratory Gases

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Separation of charges meansPotential Energy
(voltage)
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Nerst potential

• Opposition to ion movement
• EMF (mV) /- 61 x log (ions in / ions out)
• ions in mEq
• - 61 for cations
• 61 for anions
• Opposition to flow 20mV

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Conduction Potential Types

• Passive
• Cell body
• Dendrites
• Active
• Axon

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Comparison Between Passive Potential and Active
Potential
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Physiology of Cell bodies and Dendrites
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Graded Potentials Passive
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IPSP
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EPSP
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Neurophysiology Related Graph
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Synapse at neuron Cell body/Dendrites
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Summation

• Temporal
• Over time
• Rapid fire
• Spatial
• Over space
• Large number

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Summation Physiology
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Depolarization Cation in
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Axon Hillock
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Threshold
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All or None
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Action Potential Active
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Ions in AP Nerve Stimulation
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Nerve Impulse
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(No Transcript)
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Continuous Conduction
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Saltatory Conduction
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Effects of Myelin
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AP at Nodes of Ranvier
Speed 120 m/sec
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Node of Ranvier
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Repolarization
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Na/K in Repolarization
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Refractory Period
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After-Hyperpolarization
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(No Transcript)
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Neurotransmitter Synthesis
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AP ? Ca movement
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Ca Entry
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Vessicle Movement
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Neurotransmitter Vesicle
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(No Transcript)
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Synaptic Proteins for Exocytosis of NT from Neuron

• Vesicular protein (VAMP)
• Syntaxin
• SNAP-25
• 3 proteins together SNARE
• SNARE allows synaptic vesicle to fuse to plasma
  membrane of synaptic knob

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Synaptic Knob Proteins SNARE and Ca ion
channels
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SNARE complex Ca PIP2
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Summary of Ca effects

• Amount number of neurotransmitter vesicles
  releasing chemical NT
• Ca binds to protein release site
• Proteins allow for vesicle binding
• Vesicle fuses and membrane opens
• NT release due to diffusion

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Transmission Animation
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Diffusion
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Synaptic Cleft
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Postsynaptic Receptors
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Postsynaptic Membrane

• Receptors have two parts
• Binding part
• Ionophore part
• Ion channel
• Cation () in excitatory
• Anion (-) in inhibitory
• Secondary messenger system
• More prolonged, used in memory pathways
• G protein system
• Open ion channels
• Activate cAMP or cGMP
• Activate enzyme
• Activate gene transcription

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Neurotransmitters
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Neurotransmitter Classes
Several NP will also be used as hormones
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Neurochemical types

• Rapidly Acting Neurotransmitters
• Ach
• Amines
• AA
• NO
• Slow Acting Hormones
• Neuropeptide hormones
• Pituitary Hormones
• Gut Hormones

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(No Transcript)
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Neurotransmitter Physiology

• Direct Acting
• Ionotrophic
• NT opens gated ion channels
• ACh at Nicotinic
• Indirect Acting
• Metabotrophic
• NT signals 2nd messenger system
• ACh at muscarinic

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Direct Acting NT
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NT Receptors for Direct Acting
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Direct Acting Inotrophic NT
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Indirect Acting Metabotrophic 2nd Messenger
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Secondary Messenger Receptors for NT
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Secondary Messenger cAMP
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Secondary Messenger PIP
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(No Transcript)
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Must Know Neurotransmitters
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Cholinergic Neurons
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Cholenergic Receptors

• Nicotinic
• Neurons
• Skeletal m
• Action
• Direct
• Ionotropic
• Muscarinic
• M1, M2, M3
• Involuntary m
• Glands
• Action
• Indirect
• Secondary msgr

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Cholenergic Antagonists
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Cholinesterase Inhibitors
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Adrenergic Neurons
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Adrenergic Receptors

• Alpha
• 1
• 2
• 3
• Beta
• 1
• 2

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Alpha Adrenergic Receptor
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Adrenergic Receptor Classes

• Alpha 1
• Release Ca
• Excitatory
• Alpha 2
• Decrease cAMP
• Inhibit _at_ presynapatic
• Excitatory_at_ postsynaptic
• Beta increase cAMP
• Beta 1, 3, 4 Excitatory
• Beta 2 Inhibitory

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Alpha Receptor Location

• Alpha 1
• CNS
• BV
• heart, liver, GI, salivary glands
• Alpha 2
• CNS
• platelets
• BV

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Beta Receptor Locations

• Beta 1
• Heart, platelets, GI tract, salivary glands
• Beta 2
• Bronchi, liver, skeletal muscle, mast cells, BV
• Beta 3
• adipose
• Beta 4
• Heart

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Post Synaptic Membrane
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NMJ Nictonic Receptors
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NMJ Histology
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(No Transcript)
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Neuro-Glandular Junction
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Post Synaptic Membrane Response
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Neurotransmitter Removal
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Methods of NT removal

• Enzyme
• Ach-esterase
• MAO
• COMT
• Action
• Broken Down
• Reused/Reuptake
• Diffusion

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Serotonin Re-Uptake
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MAO breakdown
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Clinical use for NT Re-Uptake
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SSRI
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NT and Emotions
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Intercommunication
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Neuron Processing

• Neuron Pools
• Circuits
• Diverge
• Converge
• Reverberating
• Processing
• Serial
• Parallel

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Circuits and Processing

• Diverge
• Converge
• Reverberating
• Parallel
• Serial

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(No Transcript)
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Problems
Neuron Death
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Questions?