2.7 Vanderah (1) Flashcards
Most neurons in the nervous system are of these types
- interneurons
- 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?
- synaptic terminals
- 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
- myelin between two nodes
- formed by a single Schwann cell
myelination of smaller axons in peripheral nerves
- most are unmyelinated
- groups of axons are embedded in individual Schwann cells
oligodendrocytes
- myelinate CNS axons
- produce internodes on multiple axons
- a single oligodendrocyte may have dozens of branches
Do oligodendrocytes envelop unmyelinated CNS axons?
no
Where are oligodendrocytes most commonly found?
white matter
two classes of astrocytes
- protoplasmic (in gray matter)
- fibrous (in white matter)
Where do astrocyte processes attach
everywhere
- capillaries
- surface of CNS
- dendrites
- synaptic endings
- nodes of Ranvier
What do astrocytes do for the CNS?
- regulate ionic concentrations
- transfer metabolites
- control blood flow
- modulate synaptic function
- respond to injury by multiplying and forming gliotic scars
ependymal cells
- epithelial lining in the ventricles
- produce CSF
microglial cells size
smaller than oligodendrocytes and astrocytes
microglial cells: what is their role?
nervous system’s response to injury
- sweep through extracellular spaces looking for damage or disease
- proliferate and transform into macrophages to devour debris
