Lecture 7: CNS Response to Injury Flashcards
What 2 cells are formed from spongioblasts?
Astrocytes and oligodendrocytes
What are microglia?
Monocytes from peripheral blood
What happens if a neuron forming a peripheral nerve doesn’t reach its target?
Apoptosis
What myelinates a peripheral nerve axon?
Schwann cell
What myelonates a central tract axon?
Oligodendrocytes
What are the 3 kinds of nerve injury?
Neuropraxia (endoneurium and axon are intact)
Axonotmesis (Endonerium is intact, axon is damaged)
Neurotmesis (Endoneurium and axon are damaged)
Which injury can you recover from? Which are not recoverable without surgery?
Neuropraxia does not need surgery
Neurotmesis needs surgery
Axonotmesis might need surgery
Why is the axon transport system important?
Keeps the axon alive by removing waster material back to the cell body/neuron and bringing “food” from the cell body/neuron
What is Wallarian degeneration in the peripheral nervous system?
Damage sever enough to result in degeneration of the axon distal to injury
What does the cell body/neuron do?
Chromatolysis
What is chromatolysis?
Swelling with nucleus moving to periphery
What do macrophages do?
Eat myelin debris
Signal schwann cells to replicate
What do the schwann cells do?
Dedifferentiate to premyelinating state and create pathway for growth of the growth cone/new axon
Is glutamate excitatory or inhibitory?
Excitatory
What does glutamate allow into the cell?
Calcium
Why does the CNS not show regeneration of the pons like the PNS?
Because the oligodendrocytes are (insert bad word here)
Neurons do not show chromatolysis
Microglia are slow and produce inflammatory cytokines
Astrocytes create glial scars
What cell is the macrophage of the CNS?
Microglia
Which is better at encouraging axonal repair, schwann cells or oligodendrocytes?
Schwann cells
Astrocytes prevent axonal growth by forming what?
Glial scar
What 2 locations in the adult brain are neural stem cells found?
Olfactory bulbs (subventricular zone) Hippocampus (subgranular zone)
If you lose a motor neuron, what are 2 processes that another motor neuron help fill the deficit?
Rerouting
Collateral sprouting
What is the most common type of nerve injury?
Neuropraxia
What does neuropraxia do?
Prevents transmission/conduction of electrical impulses
What occurs with axonotmesis?
Distal wallerian degeneration, but spontaneous regeneration can occur
What occurs with neurotmesis?
Distal wallerian degeneration, but spontaneous regeneration cannot occur
