Myelin And Glia Flashcards
What is the difference between neurons and Glial cells?
Neurons transmit
Glial cells do not transmit
What is the role of a neuron?
Receive stimuli and transmit action potentials to other neurons or to effector organ
What are the 5 ways glial cells support and protect neurons?
Supporting organ structure
Helping produce CSF
Responding to inflammation and infection
Forming myelin sheath around axons
Providing nutrients
How fast are action potentials conducted?
45-120 m/s
Where do oligodendrocytes form myelin at?
CNS
Where do Schwann cells form myelin at?
PNS
What do myelin sheaths do?
Insulate the axons and speed transmission
What is Saltatory conduction?
Action potential jumps from node to node
What do the processes of astrocytes cover?
Surfaces of neurons, blood vessels, and Pia mater
What are astrocytes part of?
Blood brain barrier
What do astrocytes regulate?
Extracellular brain fluid composition
What is an astrocyte?
Glial cell of the CNS
What is an ependymal cell?
Glial cell of CNS
What do the ependymal cells line?
Ventricles of the brain and central canal of spinal cord
What do ependymal cells form?
Choroid plexuses
What do choroid plexuses do?
Secrete CSF (cilia help move fluid)
What is a microglia?
Glial cell of CNS
What does a microglia do?
CNS specific immune cell (phagocytic invaders of CNS like infection)
What is an oligodendrocyte?
Glial cell of CNS
What do the extensions of oligodendrocytes form?
Part of the myelin sheaths of several axons within the CNS
How many axons can 1 oligodendrocyte form myelin sheath over?
Multiple
How many axons can 1 Schwann cell form myelin sheath over?
1 axon
What are the glial cells of the PNS?
Schwann cells
Satellite cells
What do satellite cells surround?
Neuron cell bodies in sensory/autonomic ganglia (to protect)
