NBBS - organisation of nervous system Flashcards
(47 cards)
What does it mean by neurons being polarised?
Information only flows in one direction
What is the resting membrane potential in neurons?
-70mV
How much is transmission delayed at synapses?
0.3-0.5ms
What determines the output of a synapse?
the receptor (not neurotransmitter)
What is white matter?
myelinated axons
What is grey matter?
cell bodies, dendrites, axons
How is grey matter organised?
nuclei, ganglia and layers
What do layers in grey matter allow?
spatially distributed info (map), and modularity
What do nuclei allow?
group of cells with similar functions to maximise efficiency
What are double cortex syndrome and lissencephaly?
cortex layering diseases
What layer of the cortex are projection neurons in?
layer 5
Are projected neurons myelinated?
yes
What part of the CNS do motor neurons exit?
ventral side
What part of the CNS do sensory neurons enter?
dorsal side
Where does the SNS arise from?
thoracic spinal cord
Where does the PNS arise from?
cranial and sacral
What cells are made in the neural crest?
peripheral nervous system
How are CNS cell type differentiated?
by their dorso-ventral position in the neural tube
Where do CNS cells arise from in the neural tube?
inner ventricular surface
How do neurons migrate in development?
radial and tangenital migration
What is the role of radial cells?
- scaffold in adults
- projenitor cells in development & guide migrating neurons
- source of astrocytes in brain injury
What are the roles of astrocytes?
- blood brain interface
- homeostasis
- removal of excess K+ at nodes
- insulation of synapse
- removes neurotransmitter in synapse
What are reactive astrocytes?
they can form glial scars and trigger epilepsy
What are the four features of the cerebral cortex?
- regional specialism
- distributed networks
- asymmetry
- maps
