PSL 425 FINAL EXAM LATEST
QUESTIONS AND
ANSWERS 2026 - 2027
What is a feature of a graded response? - ANSWERS-Nonregenerative
What is the name given to the dissipation of graded signals over
distances of a few millimeters? - ANSWERS-Electrotonic spread
What does increasing the diameter of the axon do? - ANSWERS-
Decreases the internal resistance of the cable
What feature of a myelinated axon minimizes loss of current across the
leaky axonal membrane and forces the current to flow longitudinally
along the inside of the fiber? - ANSWERS-Large membrane resistance
What is the mode of impulse propagation that the nodes of Ranvier aid
in? - ANSWERS-Saltatory conduction
What is the unit for the parameter lambda that is referred to as the length
constant or the space constant? - ANSWERS-Distance
END OF
PAGE
1
, PSL 425 FINAL EXAM LATEST
QUESTIONS AND
ANSWERS 2026 - 2027
What effect would increasing the diameter of an axon have on the length
constant? - ANSWERS-Increase
The cable parameters of length constant and time constant are a function
of material properties that include ___________. - ANSWERS-
Resistance
Capacitance
Cell shape and tissue anatomy
What cable parameter(s) is/are responsible for slower conduction in
myelinated fibers with a very small diameter (<1 um) versus
unmyelinated axons of the same outer diameter? - ANSWERS-High
internal resistance
As myelin is eliminated, propagated action potentials may ultimately fail
to reach the next node of Ranvier and thus result in nerve blockage.
What cable parameter(s) is/are responsible? - ANSWERS-Decreased
membrane resistance
END OF
PAGE
2
, PSL 425 FINAL EXAM LATEST
QUESTIONS AND
ANSWERS 2026 - 2027
Who is credited with coining the term synapse? - ANSWERS-Charles
Sherrington
What is a feature electrical synapses have that chemical synapses do
not? - ANSWERS-Small separation between cells
What type of gap junctions allow depolarizing current to pass readily in
only one direction, from the presynaptic cell to the postsynaptic cell? -
ANSWERS-Rectifying synapses
What name is given to the relationship of the electrical current that
passes through gap junctions with equal efficiency in both directions? -
ANSWERS-Ohmic
The increase in intracellular concentration of which ion triggers the
fusion of synaptic vesicles with the presynaptic membrane? -
ANSWERS-Calcium
END OF
PAGE
3
QUESTIONS AND
ANSWERS 2026 - 2027
What is a feature of a graded response? - ANSWERS-Nonregenerative
What is the name given to the dissipation of graded signals over
distances of a few millimeters? - ANSWERS-Electrotonic spread
What does increasing the diameter of the axon do? - ANSWERS-
Decreases the internal resistance of the cable
What feature of a myelinated axon minimizes loss of current across the
leaky axonal membrane and forces the current to flow longitudinally
along the inside of the fiber? - ANSWERS-Large membrane resistance
What is the mode of impulse propagation that the nodes of Ranvier aid
in? - ANSWERS-Saltatory conduction
What is the unit for the parameter lambda that is referred to as the length
constant or the space constant? - ANSWERS-Distance
END OF
PAGE
1
, PSL 425 FINAL EXAM LATEST
QUESTIONS AND
ANSWERS 2026 - 2027
What effect would increasing the diameter of an axon have on the length
constant? - ANSWERS-Increase
The cable parameters of length constant and time constant are a function
of material properties that include ___________. - ANSWERS-
Resistance
Capacitance
Cell shape and tissue anatomy
What cable parameter(s) is/are responsible for slower conduction in
myelinated fibers with a very small diameter (<1 um) versus
unmyelinated axons of the same outer diameter? - ANSWERS-High
internal resistance
As myelin is eliminated, propagated action potentials may ultimately fail
to reach the next node of Ranvier and thus result in nerve blockage.
What cable parameter(s) is/are responsible? - ANSWERS-Decreased
membrane resistance
END OF
PAGE
2
, PSL 425 FINAL EXAM LATEST
QUESTIONS AND
ANSWERS 2026 - 2027
Who is credited with coining the term synapse? - ANSWERS-Charles
Sherrington
What is a feature electrical synapses have that chemical synapses do
not? - ANSWERS-Small separation between cells
What type of gap junctions allow depolarizing current to pass readily in
only one direction, from the presynaptic cell to the postsynaptic cell? -
ANSWERS-Rectifying synapses
What name is given to the relationship of the electrical current that
passes through gap junctions with equal efficiency in both directions? -
ANSWERS-Ohmic
The increase in intracellular concentration of which ion triggers the
fusion of synaptic vesicles with the presynaptic membrane? -
ANSWERS-Calcium
END OF
PAGE
3
