Which of the following takes place during an action potential? Na+ ions exit the cell causing depolarization Repolarization occurs when K+ ions enter the cell The membrane becomes more negative during depolarization K+ ions start the action potentials Na+ enters the cell making the membrane potential positive.

If a post synaptic neuron is stimulated to threshold by spatial summation this implies that the post synaptic cell has a lower than normal threshold the postsynaptic cell has many synapses with many presynaptic neurons the post synaptic cell is getting stimulated many times during a short period of time by a single presynaptic neuron the post synaptic cell is slow to repolarize

You find a neuron whose resting potential is -90mV. Which of the following are likely to be true? (select all that apply) Voltage-gated sodium channels are closed The neuron is fully permeable to sodium The neuron is permeable to potassium The neuron is hyperpolarized

As the axonal membrane depolarizes during the rising phase of an action potential, the amplitude of Na+ conductance changes from large to small the amplitude of Na+ conductance changes from small to large there is no Na+ conductance during this phase of the action potential the amplitude of Na+ conductance remains large and constant throughout

- Which of the following describes the concentration of K+ and Na+ ions in and around a resting neuron?1- K+ and Na+ ion concentrations are both higher outside of the cell.2- K+ ion concentration is higher inside of the cell, Na+ ion concentration is higher outside of the cell.3- K+ ion concentration is higher outside of the cell, Na+ ion concentration is higher inside of the cell.4- K+ and Na+ ion concentrations are similar inside of and outside of the cell. - An action potential:1- is a large change in polarization.2- is an "all-or-nothing" response.3- will travel down the length of the axon4- all of the above - What prevents action potentials from traveling away from synaptic terminals?1- Inactivation of Na+ channels behind the zone of depolarization.2- Inactivation of K+ channels behind the zone of depolarization.3- An increased in graded potential along the length of the axon.4- All of the above - Which brain region is incorrectly paired with one of its functions?1- midbrain -…

Dr. Brainy creates a nerve cell that is only permeable to Caesium ions (Cs+1) at rest. She measures that the concentration of Caesium is 400mM outside the cell and only 50 mM inside the cell. She calculates the Equilibrium potential for Cs+1 (Ecs) to be +35 mV. If the cell is only permeable to Cs, the resting membrane potential will be: +58 mV 0 mV +35 mV -58 mV

Opening voltage-gated potassium ion channels will allow potassium ions to O enter, repolarization and hyperpolarization exit, depolarization the cell, which will lead to enter, depolarization exit, repolarization and hyperpolarization

Which of these ions is actively transported through the cell membrane to re-establish a resting potential? K and Mg  Na and K Mg and Cl Ca and Cl

How to fill out each section of the table.

Place the following events in chronological order from 1-8: Nat enters the cell, and depolarization occurs to approximately +30 mV. The voltage across the cell membrane is -70 mV, the resting membrane potential. Upon reaching the peak of the action potential, the VG Nat channels are inactivated by the closing of their inactivation gate and the activation gate of each VG K channel opens. VG K channels close by the closing of their activation gate, and the resting membrane potential is gradually restored. An excitatory post-synaptic potential depolarizes the membrane to threshold and the activation gate of VG Nat channels open. Upon returning to the resting membrane potential, VG Na channels are reset by opening of the inactivation gate and the closing of the activation gate. VG K+ channels are slow to close, resulting in an excess of K* efflux and hyperpolarization. Depolarization occurs as K+ flows out of the cell.