Cells of the nervous system

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Cells of the nervous system

• Neurons
• Support cells

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External structure of neurons

• Soma
• Dendrites
• Axon
• Terminal buttons
• Dendritic spines

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Neuron types

• Based on external structure
• Unipolar neurons
• Bipolar neurons
• Multipolar neurons
• Based on function
• Sensory neurons
• Motor neurons
• Interneurons

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Internal structure of neurons

• Membrane Phospholipid bilayer
• Outer membrane
• Organelle membrane
• Nucleus
• Cytoplasm
• Organelles

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Organelles

• Mitochondria
• Rough endoplasmic reticulum
• Attached ribosomes
• Free ribosomes
• Smooth endoplasmic reticulum
• Golgi apparatus
• Exocytosis
• Lysosomes

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Cytoskeleton

• Insoluble matrix of protein
• Microfilaments
• Microtubules
• Axoplasmic transport
• Anterograde Kinesin
• Retrograde Dynein

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Support cells

• Glial cells or glia
• Astrocytes
• Glucose --gt Lactate Stored glycogen
• Structural matrix
• Phagocytosis
• Oligodendrocytes
• Myelin and nodes of Ranvier
• Microglia
• Schwann cells

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The blood-brain barrier

• Ependymal cells
• Pia mater
• Glial feet
• Tight capillary cell junctions
• Exceptions Area postrema

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The blood-brain barrier
Glial feet
Basement membrane (Pia mater)
Capillary With Tight junctions
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Communication within a neuron

• Microelectrodes and electrical potentials
• The resting potential
• Diffusion
• Electrostatic pressure
• Sodium-Potassium pump
• Stimulation and thresholds
• Depolarization
• Hyperpolarization

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Neural transmission

• Resting potential -70mV
• Pump Na out, K in
• Action potential 50mV
• Allow Na in, K out
• Refractory period -80mV
• Restore resting potential

mV
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Ion movements
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Ion movements
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Surface glycoprotein
Receptor proteins
Integral glycoprotein
Ion channel
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Oligodendrocyte myelination