Glia Flashcards
How do glia impulses spread?
Slowly
Functionsof Glia
- Metabolic activity
- Blood flow
- Extracellular environment of NS
- NT kinetics
- Neuronal activity
Astrocytes
Most common glia cell, involved in regulation of capillary flow, metabolism and the exchange between neural tissue and the blood stream
A single astrocyte interacts with …
several neurons, they regulate their environment, metabolism, regulate the synapses and their excitability
Microglia
Specialized macrophages, part of the immune system, activated by damage or infection, engulf and destroy pathogens, foreign bodies and dead or dying neurons
Microglia have a
Stationary and mobile phase
Oligodendrocytes
Produce myelin, these are multiple layers of fatty cell
membranes that make up the myelin sheath around axons in the brain.
Shwann cells
Produce the myelin sheath for axons in the PNS. They also take up some of the functions of astrocytes in PNS, uptake and processing of NT’s in synapses especially in neuromuscular junctions and maintenance of the extracellular environment
Precursor cells
Immature glia cells which can specialise into oligodendrocytes, astrocytes and even neurones -> important in regneration
Difference between Oligodendrocyte and Astrocyte precursors
Astrocyte precursors don’t spread extensively
Fibrous Astrocytes
Found in white matter of CNS, long sparsely-branched processes
Protoplasmic Astrocytes
Found mainly in grey matter, numerous short and highly branched processes
Bergman glia
Found in the cerebellum
Muller glia
Found in the retina
How do astrocyte’s participate in the blood-brain barrier?
Astrocyte endfeet have receptors, transporters, channels and regulate the interface between blood and the brain.
