Glia and Neurons Flashcards
What is the “cell theory” and who proposed it?
The tissues of all organisms are composed of cells
Proposed by T. Schwann
What is the “neuron doctrine” and who proposed it?
Neurons are special cases of the cell theory
Proposed by Ramon y Cajal
Ramon y Cajal used _____ studies and the methods developed by _____ to show that neurons are not continuous.
lesion/degeneration
Golgi
Transmission of nerve impulses shows a _____.
delay
Flw of information in a neural chain is _____.
unidirectional
Transmission at synapses was found to be _____ as well as ______.
excitatory
inhibitory
“Glia” comes from the Greek word for _____.
glue
Glia cells outnumber neurons by a ration of ~:
Ratios vary considerably by brain area.
3
1
_____ surround neurons and hold them in place.
Astrocytes
_____ and _____ supply nutrients and oxygen to neurons.
Astrocytes
Ependymal cells
_____ insulate one neuron from another.
Oligodendrocytes
_____ destroy pathogens and remove dead neurons.
Microglia
_____ modulate neurontransmission by making more or less neurotransmitter-precursor available.
Astrocytes
Microglia are _____.
phagocytes
Microglia arise from _____ of blood cells outside the CNS.
progenitors
In microglia’s “resting state,” they _____.
move around and survey their domain for debris.
After injury or inflammation, microglia are _____ and migrate to the site of injury to help clear dead and dying cells.
activated
Microglia _____ the debris in the brain.
phagocytose
wrap around and “swallow”
Microglia can also produce small molecules called _____ that trigger cells of the immune system to respond to the injury site.
cytokines