PHY2011 Lecture Notes - Lecture 6: Schwann Cell, Oligodendrocyte, Ependyma
20 Jun 2018
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Week 2 L3 (T2L1) The nervous system
Cells of the nervous system
oDendrites, where neurons receive most of their input.
oCell body, with organelles for synthesis &/or processing of proteins, lipids etc.
oAn axon, to transmit information, generally extending from the cell body.
oA “skeleton” of:
Filaments for rigidity
Microtubules for transport
Extends the entire length of the neuron.
oAxon terminals, at specialized regions, called synapses, where the neuron
functionally contacts other cells
Neurons make up 10% of the nervous system
[Neuro]Glial cells -5 different types (90% of the nervous system)
Glue neural cells together
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Provide structural support in the nervous system
Nourish neurons
Scavenge debris & dying cells
Sheath nerves
Generally maintain an optimal environment for neuronal function
oAstroctye: Multipurpose cell
Provides nutrients from blood to neurons
Takes waste products in opposite direction
Controls extracellular environment around neurons
Regulates metabolism
Controls capillary blood flow to control flow of chemicals between blood
and neurons
oOligodendrocytes and Schwann cells:
Both provide myelin sheath around axon of some neurons
Maintain optimal extracellular environment
Only difference is location
oEpendymal cells:
Line brain’s fluid spaces (the ventricles) to form a slight barrier -BBB
- Also affects the removal of toxins Astrocytes necessary
Some ependymal cells can divide & form neurons through life
oMicroglia:
Specialized immune cells converted from being macrophages when are
found in blood (and body tissues) into Microglia when they enter the brain
(when there is breakdown of the BBB)
Organisation of the nervous system
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Extends the entire length of the neuron: axon terminals, at specialized regions, called synapses, where the neuron functionally contacts other cells. Neurons make up 10% of the nervous system. [neuro]glial cells -5 different types (90% of the nervous system) Generally maintain an optimal environment for neuronal function: astroctye: multipurpose cell. Controls capillary blood flow to control flow of chemicals between blood and neurons: oligodendrocytes and schwann cells: Both provide myelin sheath around axon of some neurons. Only difference is location: ependymal cells: Line brain"s fluid spaces (the ventricles) to form a slight barrier -bbb. Also affects the removal of toxins astrocytes necessary. Some ependymal cells can divide & form neurons through life: microglia: Specialized immune cells converted from being macrophages when are found in blood (and body tissues) into microglia when they enter the brain (when there is breakdown of the bbb) Organisation of the nervous system: neurons aren"t scattered randomly in cns or pns.
