cellular constituents Flashcards
Some function can be restored by _____ neurons taking over some of the function.
surviving
once a neuron dies it is generally replaced/not replaced ?
not replaced
swelling of the cell bodies and the nuclei moves toward the plasma membrane
chromatolysis
The ________ results in the neuronal cell bodies undergoing chromatolysis
retrograde effect -
wallerian degeneration
the anterograde effects that results from cutting of axons .results in degeneration of the axon beyond the transection sites.
Oligodendrocyte– Myelination
Ratio
1 oligo: many axons
Component of blood-brain barrier; modulation of neuronal microenvironment
astrocyte
Line cerebral ventricles; ciliated; produce CSF
ependymal cells
latent phagocytic macrophages in CNS
microglial
Found in peripheral ganglia; provide support & modulate neuronal microenvironment
Satellite cell
Schwann cells lay down a _____ which forms an impervious “tube” surrounding the length of the axon.
basal lamina
can glialmyelinate axons, even after injury?
yes
Glial scars also provide a barrier to _____
regeneration
Glial cells give rise to most of the brain tumors: ______ and______
astrosytomas
glioblastomas
Multiple Sclerosis is the loss of myelin in the CNS. Which glial cells are implicated in this disease?
oligodendrocytes
Movement of substances from cell body to axon terminal
anterograde transport
what undergoes anterograde transport
Newly synthesized proteins; organelles; neurotransmitter precursors
Movement of substance from axon terminal to cell body
Retrograde transport
what sorts of things move by retrograde transport
Molecules destined for degradation in lysosomes; viruses such as herpes simplex & polio; Axonal transport moves organelles, lipids, proteins, along axon
Utilizes axonal cytoskeleton of microtubules, and the motor proteins
_____ protein is involved in retrograde transport
dyenin
______ protein is involved in anterograde transport
kinesin
_____ transport moves slow
anterograde
_____ transport moves fast and slow
anterograde and retrograde (intermediate quasi fast) transport
A molecule destined for destruction in a lysosome is likely to be transported by which of these?
Dynein, retrograde
Depending upon the ______, the response can range from death to regeneration
severity of the insult
anomalous reinnervation
when damaged neurons sprout along the wrong rein nervation pathway/incorrect target
onset of neuroma
takes several months
neuroma
collection of neurons that did not find the basal lamina and form a rein nervation pathway…
where does regeneration occur? CNS or PNS? Why?
PNS has basal lamina from Schwann cells. Oligodendrocytes lack a basal lamina. Inhibitory factors are also present.
regeneration in the CNS - Astrocytes may form a glial scar, presenting a _____ to growth
physical barrier
neuronal restoration - axon membranes acquire new voltage-gated Na+ channels in demyelinated regions to restore function
Molecular plasticity
synaptic can be strengthened at some synapses through increased activity
synaptic plasticity
targets which become partially denervated can receive axon collaterals from the remaining axons to the denervated portion of the tissue
Collateral sprouting of axons
new neurons produced from undifferentiated progenitor cells
neurogenesis
successful nerve regeneration timeline
3 months after injury
