Download Neurons & Glia

Neurons
& Neuroglia
Lesson 3
Basic Cell Biology
Eukaryotic cells
 Cell membrane
 Nucleus
 chromosomes
 Cytoplasmic organelles
 Mitochondria
 Endoplasmic reticulum
 ribosomes
 microtubules & microfilaments ~

Neurons
Basic functional unit of N.S.
 Specialized cell
 All cells have same basic
properties
 Regulation of behavior
 Information processing
 Transmits
 Integrates
 Stores ~


Dendrites & Soma
 Receives & Integrates information
 electrical signal within ~
Stimuli

Axon carries information away from soma
 Electrical signal within
 Axon terminal releases chemical message ~
By function (connections)
Sensory
Motor
Interneuron
By morphology (# of neurites)
Multipolar
Bipolar
Unipolar
Neurons vs. Nerves
Neurons - cells
 microscopic
 Nerves - bundles
of axons
 seen with
naked eye ~

Neuroglia
Neural support cells
 local influence at synapse
 no role long distance signaling
 Functions
 exchange molecules with neurons
 physical support
 maintains microenvironment
 Blood-brain barrier
 immune system ~

Astrocytes
Provide physical support
 Regulating chemical content of
extracellular fluid
 localizes neurotransmitters
 K+ concentration
 Blood-brain Barrier (BBB) ~

BBB: Function
Maintains stable brain environment
 large fluctuations in periphery
 Barrier to poisons
 Retains neurotransmitters & other
chemicals
 Regulates nutrient supplies
 glucose levels
 active transport ~

Blood-Brain Barrier
astrocytes
Typical
Capillary
Intercellular
cleft
Fenestra
No
fenestra
Brain
Capillary
tight
junction
Neuroglia: Myelin
Wrap around axon
 Saltatory Conduction
 faster transmission
 CNS: oligodendrocytes
 PNS: Schwann cells ~

Microglia

Immune-like function
 macrophage
 foreign cells
 cellular debris ~