Synapse Flashcards
what is a neurotransmitter
chemicals that are the primary means of communication b/w cells
allow neurons to communicate w/ other cells
what happens when neurotransmitters cross the synapse and bind with post-synaptic receptors
conformational change
what is the conformational change
protein changes shape and alters the fxn of the receiving neuron
presynaptic side
axon terminal
sender
post synaptic side
dendrite or soma of another neuron
receiver
synaptic cleft
space b/w the 2 sides
synaptic transmission
transfer of info across the synapse
neuroglia
support cells of the NS
compared to neurons, neuroglia are
smaller
10x more numerous
CNS Neuroglia
astrocytes
oligodendrocytes
microglia
ependymal cells
astrocytes
stellate shaped cells
forming a perivascular covering around blood vessels
numerous
long processes
what do astrocytes extend b/w
neurons and vascular elements
what do astrocytes occupy
much of the extracellular space of the CNS
fxn of astrocytes
provide physical and nutritional support to the neurons of CNS
isolate neurons from each other
metabolize extracellular NTs (glutamate, GABA, serotonin)
fxn of astrocytes cont
help migration of developing cells during embryogenesis
form glial scar tissue after damage to the CNS
act as a K+ and Na+ buffers
proliferate after trauma
swell
accumulate glycogen and undergo fibrosis by accumulation of filaments
2 types of astrocytes
fibrous astrocytes
protoplasmic astrocytes
fibrous astrocytes
in white matter
protoplasmic astrocytes
gray matter
oligodendrocytes
produce myeline sheath
have small nuclei
how many neurons can oligodendrocytes myelinate
multiple
what do patients with MS have issues with
oligodendrocytes
microglia
phagocytes arising from monocytes
referred to as CNS scavengers
what do microglia compromise
~15% of the total cells of the CNS
where are microglia found
all regions of the brain and spinal cord
are microglia mobile in the brain
yes
what do microglia do when the brain is damaged
multiply
ependymal cells
epithelial cells of the ventricles
produce CSF
PNS neuroglia
satellite cells
schwann cells
satellite cells
surround clusters of neuronal cell bodies in PNS
role of satellite cells
similar to astrocytes
supply nutrients to the surrounding neurons
some structural fxn
protective and cushioning cells
schwann cells
form myeline sheaths around the large nerve fibers in the PNS
what are schwann cells vital for
neuronal regeneration
how many neurons can schwann cells myelinate
ONE
point of contact
where one neuron comes into contact w/ another neuron
how do neurotransmitters synthesized
by the neuron
where are NT stored
vesicles at the nerve terminal
stored before they are released
