Most neurons in the nervous system are of these types
- projection neurons
sensory axons: cell body types
pseudounipolar
motor axons: cell body type
multipolar
multipolar neurons
multiple dendritic projections and an axon
bipolar neurons
two dendritic processes
unipolar neurons
one dendrite
dendritic tree
total array of dendrites
What are dendrites surrounded by?
- processes of glial cells
dendritic spines
preferred sites for some synapses
anterograde transport
transport away from the soma
retrograde transport
transport toward the soma
slow transport
moves soluble proteins in anterograde direction
fast transport
moves membrane associated substances
All PNS glial cells are variants of these
Schwann cells
satellite cells
flattened Schwann cells that surround neuronal cell bodies in PNS ganglia
internode
- formed by a single Schwann cell
myelination of smaller axons in peripheral nerves
- groups of axons are embedded in individual Schwann cells
oligodendrocytes
Do oligodendrocytes envelop unmyelinated CNS axons?
no
Where are oligodendrocytes most commonly found?
white matter
two classes of astrocytes
- fibrous (in white matter)
Where do astrocyte processes attach
everywhere
What do astrocytes do for the CNS?
ependymal cells
- produce CSF