The equlibrium potential

The resting potential

The driving force

Two of the above are correct

The membrane potential

Cl

K

Two of the above are correct

Ca

Na

It is an ATP-dependant enzyme

It is a trasmembrane protein

The channel pore is selectively permeable to only K ions

It is a multimeric protein consisting of several subunits

Two of the above are incorrect

Yes, because the intracellular and extracellular ionic concentrations are different, and molecules always diffuse down their concentration gradients

Yes, because neurons have a resting potential, meaning that V does not = 0, and there are channels in the membrane, so g does not = 0

No, because there is almost no driving force for K, and because there is almost no conductance for Na

None of the above is correct

No, because there are no open channels and thus g=0

Two of the above are correct

This is a trick question; excessive extracellular K does not affect neurons aversely

It uses ATP- dependent Na/K pumps to remove the extra K

It yses K leak channels to allow the extra K leak out of the central nervous system

It uses specialized glial cells called astrocytes to remove the extra K

Voltage-gated Na channel

Voltage-gated (delayed rectifying) K channel

Na/K ATPase

Voltage-gated Ca channel

K leak channel

The membrane potential will proportionally get more and more postitive (or less and less negative)

The membrane potential will rise, but if enough current is injected the membrane potential will spike. The frequency of the spikes will increase with increased current injection.

The membrane potential will rise, but if enough current is injected the membrane potential will spike. The amplitude of the spike will increase with increased current injection.

The membrane potential will get more positive, but reach a plateau and no longer increase

None of the above are correct

During the rising phase when the membrane potential is rapidly increasing

During the falling phase when the membrane potential becomes negative again

During the undershoot phase, when the membrane is hyperpolarized lower than the resting potential.

When the membrane is at its resting potential

During the overshoot phase when the membrane potential rises above 0 mV

acetylcholine-gated cation channel

voltage-gated Ca channel

voltage-gated Na channel

K leak channel

delayed rectifying K channel

Intracellular Ca released from the endoplasmic reticulum

None of the above is correct

Extracellular Ca entering the axon terminal through voltage-gated Ca channels

Intracellular Ca exiting the axon terminal through voltage-gated Ca channels

Intracellular Ca released from the synaptic vesicles

Yes, sometimes by directly causing a channel pore to open in the receptor, allowing ions to flow through

Yes, it can sometimes act through the shortcut pathway wherein activated heterotrimeric G proteins directly affect ion channel activity

No; metabotropic receptors always act by triggering gene transcription and therefore are signifcantly slwoer than ionotropic receptors

None of the above is incorrect

No; metabotropic receptors always act through second messengers and therefore are significantly slower than ionotropic receptors by minutes

A large synapse will likely trigger an action potential with larger amplitude

Two of the above are correct

A larger synapse will likely be more resistant to neurotoxins

A large synapse will likely contain more postsynaptic receptors, and therefore have a greater postsynaptic response to neurotransmitter release

A large synapse will likely contain more synaptic vesicles, and therefore lead to more neurotransmitter release

The molecule is synthesized and stored in the presynaptic neuron

The molecule generates a postsynaptic response similar to when the presynaptic neuron is stimulated

The molecule is secreted by the presynaptic axon terminal

The receptor for the neurotransmitter is expressed in the postsynaptic neuron

None of the aboe is correct