NSC Ch. 5Verified Practice Questions with A+
Answers | Final Exam Guide FOR 2025/2026 (the
most recent quizzes)
synaptic transmission - process of information transfer at a synapse
two types: electrical and chemical
electrical synapses - synaptic transmission via electrical current flowing from one neuron
to the next
occur through gap junctions that ions pass directly from cytoplasm of one cell to cytoplasm of
the other
at the junctions, channels called connexons (2 per channel) form gap junction channels that ions
pass through
transmission is bidirectional and very fast
when connected by by gap junctions, said to be electrically coupled
AP in the presynaptic neuron causes a small amount of ionic current to flow across the gap
junction channels into the other neuron causing PSP
chemical synapses - chemical neurotransmitters transfer information from one neuron to
another at the synapse; most
presynaptic and postsynaptic membranse separated by synaptic cleft that's filled with a matrix
of fibrous extracellular protein
, presynaptic element usually an axon terminal, which contains dozens of synaptic vesicles inside
of which are neurotransmitters and the terminal may also contain secretory vesicles
postsynaptic potential (PSP) - AP caused in the second neuron in an electrically coupled
neurons
secretory granules - large vesicles in axon terminals that contain soluble protein that
appears dark in the electron microscope
also called dense-core vesicles
membrane differentiations - dense accumulations of protein adjacent to and within the
membrane on either side of the synaptic cleft
active zones - sites of the neurotransmitter release; located on the presynaptic side
postsynaptic density - the protein thickly accumulated in and just under the postsynaptic
membrane
contains the neurotransmitter receptors which convert the intercellular chemical signal into an
intracellular signal in the postsynaptic cell
axodendritic - postsynaptic membrane is on a dendrite
axosomatic - postsynaptic membrane is on the cell body
axoaxonic - postsynaptic membrane is on another axon
dendrodendritic - dendrites that form synapses with one another
Gray's type I synapse - synapses in which the membrane differentiation on the
postsynaptic side is thicker than that on the presynaptic side
aka asymmetrical synapses
Gray's type II synapse - those in which the membrane differentiations are of similar
thickness
aka symmetrical synapses
Answers | Final Exam Guide FOR 2025/2026 (the
most recent quizzes)
synaptic transmission - process of information transfer at a synapse
two types: electrical and chemical
electrical synapses - synaptic transmission via electrical current flowing from one neuron
to the next
occur through gap junctions that ions pass directly from cytoplasm of one cell to cytoplasm of
the other
at the junctions, channels called connexons (2 per channel) form gap junction channels that ions
pass through
transmission is bidirectional and very fast
when connected by by gap junctions, said to be electrically coupled
AP in the presynaptic neuron causes a small amount of ionic current to flow across the gap
junction channels into the other neuron causing PSP
chemical synapses - chemical neurotransmitters transfer information from one neuron to
another at the synapse; most
presynaptic and postsynaptic membranse separated by synaptic cleft that's filled with a matrix
of fibrous extracellular protein
, presynaptic element usually an axon terminal, which contains dozens of synaptic vesicles inside
of which are neurotransmitters and the terminal may also contain secretory vesicles
postsynaptic potential (PSP) - AP caused in the second neuron in an electrically coupled
neurons
secretory granules - large vesicles in axon terminals that contain soluble protein that
appears dark in the electron microscope
also called dense-core vesicles
membrane differentiations - dense accumulations of protein adjacent to and within the
membrane on either side of the synaptic cleft
active zones - sites of the neurotransmitter release; located on the presynaptic side
postsynaptic density - the protein thickly accumulated in and just under the postsynaptic
membrane
contains the neurotransmitter receptors which convert the intercellular chemical signal into an
intracellular signal in the postsynaptic cell
axodendritic - postsynaptic membrane is on a dendrite
axosomatic - postsynaptic membrane is on the cell body
axoaxonic - postsynaptic membrane is on another axon
dendrodendritic - dendrites that form synapses with one another
Gray's type I synapse - synapses in which the membrane differentiation on the
postsynaptic side is thicker than that on the presynaptic side
aka asymmetrical synapses
Gray's type II synapse - those in which the membrane differentiations are of similar
thickness
aka symmetrical synapses
