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of nervous system ...and with muscle cells. These junctions are
called synapses. Presynaptic terminals, when seen by light
microscope, look like small knobs and contain many organelles.
The most numerous of these are synaptic vesicles, which, filled
with neurotransmitters, are often clumped in areas of the
terminal membrane that appear to be thickened. The thickened
areas are called presynaptic dense projections,...
Neurotransmitters are packed into small, membrane-bound synaptic
vesicles. Each vesicle contains thousands of neurotransmitter
molecules, and there are thousands of vesicles in each axon
terminal. Once stimulated by Ca2+, the vesicles move through the
cytoplasm and fuse their membranes with the plasma membrane of
the terminal. The transmitter molecules are then expelled from
the... What made you want to look up "syna