Clinical Neuroscience (Clark) Exam 1
Questions And Answers
Know neuron anatomy: dendrites, soma, nucleus, axon hillock,
axon, axon terminals -
Describe the composition of inside and outside the neuronal
membrane at resting potential. -
correct answer ✅Outside Cell: (+)
○Na+ concentration high with little diffusion
○Cl- concentration high with high diffusion
Membrane:
○ions specific channels
Inside Cell: (-)
○K+ concentration high with high diffusion
○large A- proteins that don't move
Sodium-Potassium Pump -
correct answer ✅○contributes to uneven distribution of ions
○pushes out 3 Na+ for every 2 K+
○converts ATP to stored charge (ADP)
,Clinical Neuroscience (Clark) Exam 1
Questions And Answers
Resting Potential -
correct answer ✅○a neuron at equilibrium potential, the potential
at which there would be no net movement of an ion and the
potential it will move to when allowed to move freely
○neuronal stored energy (ion disequilibrium)
Equilibrium Potential -
correct answer ✅○If ions moved according to pushing forces, the
concentrations of K+ and Na+ would be opposite which is why we
need the sodium-potassium pump
○Na+=120mv
○K+=90mv
○Cl-=-70mv (same as resting potential)
Effects of Manipulating Na+ Concentrations on AP's -
correct answer ✅○changes what action potential looks like
(doesn't effect resting state)
○increasing Na+ outside of the cell increases the AP
,Clinical Neuroscience (Clark) Exam 1
Questions And Answers
Conduction of AP's -
correct answer ✅○ channels respond to voltage changes and
propel the action potential
○"all or nothing": when threshold (~-65mv) is reached the neuron
fires and the voltage-gated ○ion channels are opened
○axon hillock determines the net charge required for an AP
Depolarization Phase -
correct answer ✅○Na+ channels open quickly and Na+ runs into
cell
○K+ channels open slowly (toward end)
○interior of cell becomes positive
○threshold (~-65mv) is met and nerve impulse is sent
○goes to +40mv
Repolarization Phase -
correct answer ✅○Na+ channels close
○K+ channels open completely and K+ rushes out of the cell
○interior of cell becomes negative
, Clinical Neuroscience (Clark) Exam 1
Questions And Answers
Hyperpolarization Phase -
correct answer ✅○refractory period: absolute followed by relative
○K+ channels close slowly
○interior of cell becomes more negative than its resting potential
and will no longer respond to EPSPs
○sodium-potassium pump switches ions back to original resting
composition
Absolute Refractory Period -
correct answer ✅○first stage of the refractory period where it is
impossible to initiate another action potential
○prevents the backwards movement of APs and limit the rate of
firing
Relative Refractory Period -
correct answer ✅○second stage of the refractory period where it is
hard to initiate another action potential, but not impossible
○follows the absolute refractory period as the Na+/K+ pump brings
charge back to resting potential
Post-Synaptic Potentials (PSPs) -
correct answer ✅○signals received from other cells
Questions And Answers
Know neuron anatomy: dendrites, soma, nucleus, axon hillock,
axon, axon terminals -
Describe the composition of inside and outside the neuronal
membrane at resting potential. -
correct answer ✅Outside Cell: (+)
○Na+ concentration high with little diffusion
○Cl- concentration high with high diffusion
Membrane:
○ions specific channels
Inside Cell: (-)
○K+ concentration high with high diffusion
○large A- proteins that don't move
Sodium-Potassium Pump -
correct answer ✅○contributes to uneven distribution of ions
○pushes out 3 Na+ for every 2 K+
○converts ATP to stored charge (ADP)
,Clinical Neuroscience (Clark) Exam 1
Questions And Answers
Resting Potential -
correct answer ✅○a neuron at equilibrium potential, the potential
at which there would be no net movement of an ion and the
potential it will move to when allowed to move freely
○neuronal stored energy (ion disequilibrium)
Equilibrium Potential -
correct answer ✅○If ions moved according to pushing forces, the
concentrations of K+ and Na+ would be opposite which is why we
need the sodium-potassium pump
○Na+=120mv
○K+=90mv
○Cl-=-70mv (same as resting potential)
Effects of Manipulating Na+ Concentrations on AP's -
correct answer ✅○changes what action potential looks like
(doesn't effect resting state)
○increasing Na+ outside of the cell increases the AP
,Clinical Neuroscience (Clark) Exam 1
Questions And Answers
Conduction of AP's -
correct answer ✅○ channels respond to voltage changes and
propel the action potential
○"all or nothing": when threshold (~-65mv) is reached the neuron
fires and the voltage-gated ○ion channels are opened
○axon hillock determines the net charge required for an AP
Depolarization Phase -
correct answer ✅○Na+ channels open quickly and Na+ runs into
cell
○K+ channels open slowly (toward end)
○interior of cell becomes positive
○threshold (~-65mv) is met and nerve impulse is sent
○goes to +40mv
Repolarization Phase -
correct answer ✅○Na+ channels close
○K+ channels open completely and K+ rushes out of the cell
○interior of cell becomes negative
, Clinical Neuroscience (Clark) Exam 1
Questions And Answers
Hyperpolarization Phase -
correct answer ✅○refractory period: absolute followed by relative
○K+ channels close slowly
○interior of cell becomes more negative than its resting potential
and will no longer respond to EPSPs
○sodium-potassium pump switches ions back to original resting
composition
Absolute Refractory Period -
correct answer ✅○first stage of the refractory period where it is
impossible to initiate another action potential
○prevents the backwards movement of APs and limit the rate of
firing
Relative Refractory Period -
correct answer ✅○second stage of the refractory period where it is
hard to initiate another action potential, but not impossible
○follows the absolute refractory period as the Na+/K+ pump brings
charge back to resting potential
Post-Synaptic Potentials (PSPs) -
correct answer ✅○signals received from other cells
