Sodium is higher in the extracellular space than in the cell body of neurons, causing a chemical gradient favoring the influx of sodium into the cell.
Resting membrane potential in the cell body of a neuron is
-40 mV
-90 mV
-65 mV
What mechanism is responsible for creating the chemical charge of the membrane potential?
Na-K ATPase
Fight or flight mechanism of ANS
IPSP
In which of the following ways can an excitatory postsynaptic potential (EPSP) occur?
Opening of sodium channels
Opening of chloride channels
Closing of potassium channels
Changes to intracellular structure such as an increase in number of excitatory membrane receptors.
Action potentials are "all or nothing."
Which are stages of an action potential?
Resting stage (-90 mV)
Depolarization stage (-70 to -50 mV)
Absolute refractory period (-110 mV)
Repolarization
What is the difference between an absolute refractory period and a relative refractory period?
In a relative refractory period, only a small action potential can be generated.
There is no difference, they are two names for the same concept.
During an absolute refractory period the neuron is completely unable to generate an action potential.
During repolarization, ligand-gated sodium channels close and potassium channels open.
An action potential can be said to be self-propagating.
How are myelin sheaths formed?
Via oligodentricytes
Via glia
Via Swann cells
Via astrocytes
Which ion is responsible for binding and docking of synaptic vessels at the terminal bouton?
Sodium
Calcium
Chloride
Acetylcholine
Spatial summation refers to the successive discharges from a single presynaptic terminal.
In which ways are the influence of ESPS limited or nullfied?
Ligand-gated activation of G-protein
Decremental conduction as ESPS moves away from the cell body
Postsynaptic inhibition by release of GABA
Decrease in the number of inhibitory receptors on the cell membrane
