PHYS 261 MIDTERM EXAM QUESTIONS
AND ANSWERS 100% PASS 2026
EDITION
The nerst equation predicts - ANS the membrane potential resulting from permeability to a
single ion
the resting membrane potential results from - ANS uneven distribution of ions across the cell
membrane and differences in membrane permeability to Na+, K+, and Cl-
which ion is higher in concentration inside the cell compared to outside? - ANS Potassium
Ion channel inactivation is - ANS closing of the channel even when the stimulus continues.
which of the following is the most common location where action potentials originate -
ANS axon hillock
the falling phase of the action potential is due primarily to - ANS K+ flow out of the cell only.
the point during an action potential when the inside of the cell has become more positive than
the outside is known as the - ANS overshoot
1
@2026 EDITION ALLRIGHTS RESERVED
, inactivation gate - ANS opens during depolarization
the absolute refractory period of an action potential - ANS ensures one-way travel down an
axon, allows a neuron to ignore a second signal sent that closely follows the first, and prevents
summation of action potentials.
the sodium-potassium exchange pump - ANS reestablishes the ion gradients across the cell
membrane
the all-or-none principle states that - ANS all stimuli great enough to bring the membrane to
threshold will produce identical action potential/magnitude
When voltage-gated Na+ channels of a resting neuron open, - ANS Na+ enters the neuron
and the neuron depolarizes.
when voltage-gated K+ channels of a resting neuron open, - ANS K+ leaves the neuron
which of the following will best increase the conduction rate of action potentials ? -
ANS Increase the diameter of the axon, increase the resistance of the axon membrane to ion
leakage.
the major determinant of the resting potential of all cells is - ANS K+ gradient between inside
and outside of the cell compared
exocrine glands, smooth muscles, and cardiac muscles are controlled by the - ANS autonomic
nervous system
2
@2026 EDITION ALLRIGHTS RESERVED
AND ANSWERS 100% PASS 2026
EDITION
The nerst equation predicts - ANS the membrane potential resulting from permeability to a
single ion
the resting membrane potential results from - ANS uneven distribution of ions across the cell
membrane and differences in membrane permeability to Na+, K+, and Cl-
which ion is higher in concentration inside the cell compared to outside? - ANS Potassium
Ion channel inactivation is - ANS closing of the channel even when the stimulus continues.
which of the following is the most common location where action potentials originate -
ANS axon hillock
the falling phase of the action potential is due primarily to - ANS K+ flow out of the cell only.
the point during an action potential when the inside of the cell has become more positive than
the outside is known as the - ANS overshoot
1
@2026 EDITION ALLRIGHTS RESERVED
, inactivation gate - ANS opens during depolarization
the absolute refractory period of an action potential - ANS ensures one-way travel down an
axon, allows a neuron to ignore a second signal sent that closely follows the first, and prevents
summation of action potentials.
the sodium-potassium exchange pump - ANS reestablishes the ion gradients across the cell
membrane
the all-or-none principle states that - ANS all stimuli great enough to bring the membrane to
threshold will produce identical action potential/magnitude
When voltage-gated Na+ channels of a resting neuron open, - ANS Na+ enters the neuron
and the neuron depolarizes.
when voltage-gated K+ channels of a resting neuron open, - ANS K+ leaves the neuron
which of the following will best increase the conduction rate of action potentials ? -
ANS Increase the diameter of the axon, increase the resistance of the axon membrane to ion
leakage.
the major determinant of the resting potential of all cells is - ANS K+ gradient between inside
and outside of the cell compared
exocrine glands, smooth muscles, and cardiac muscles are controlled by the - ANS autonomic
nervous system
2
@2026 EDITION ALLRIGHTS RESERVED
