1. The membrane is more permeable to K+ than to Na+:
a. At resting membrane potential
b. During the depolarization phase of an action potential
c. After a neurotransmitter in an excitatory synapse binds tothe postsynaptic cell
d. More than one of the above is correct
2. During an action potential, the depolarization of the neuronmembrane is the result of:
a. Sodium moving into the cell
b. Potassium moving into the cell
c. Sodium moving out of the cell
d. Potassium moving out of the cell
3. Phoneutriatoxin, produced by the banana spider, slows theclosing of the voltage-gated sodium channels. which of thefollowing is the best prediction of how action potentials would beimpacted if an individual is poisoned with this toxin?
a) no action potentials would occur at all
b) the action potential would be shorter in time and smaller inmagnitude
c) the ability to fire action potentials in rapid successionwould be decreased
4. Assume that normal potassium concentration in the ICF is 140mM, and that normal potassium concentration in the ECF is 4 mM. Ifthe potassium concentration in the extracellular fluid of the braindecreases to 2 mM, neural activity in the brain would:
a. Increase b. Decrease c. Not change
