depol and AP's

[chiddler]

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A receptor-ligand interaction on the postsynaptic membrane produces an action potential at the site of interaction.

This is false, because it doesn't produce an action potential it produces a depolarization. Isn't this a bit excessively stringent? Or is this normal usage.

Then again I just remembered summation and this is starting to make more sense...still accepting opinions.

 

[kasho11]

Is this from a question or ?

Yea they're being dickish with the wording but it's technically correct. I think it's really just the test prep companies that give all these trick questions and stuff to help you learn and remember.

I've gotten so many trick questions and things that are paradoxes from Kaplan, hope all this frustration pays off.

 

[SaintJude]

I agree with the question-maker. Neurons fire action potentials and that cause membrane depolarization-And yes, that's dickish but this is the MCAT...what's new? 🙁

 

[MedPR]

A receptor-ligand interaction on the postsynaptic membrane produces an action potential at the site of interaction.

This is false, because it doesn't produce an action potential it produces a depolarization. Isn't this a bit excessively stringent? Or is this normal usage.

Then again I just remembered summation and this is starting to make more sense...still accepting opinions.

It depolarizes and produces an action potential; the two go hand in hand. Saying it doesn't produce an action potential is like saying that voluntary swallowing a bolus of food doesn't distend your esophagus, because it distends your oropharynx.

 

[chiddler]

Depolarization does not necessarily cause an action potential. For example, if the post synaptic neuron is hyperpolarized, the depolarization will bump up the membrane potential but it may not go past threshold.

What i'm now worried about is whether this is proper reasoning for mcat because it seems too much. Too specific.

 

[MedPR]

Depolarization does not necessarily cause an action potential. For example, if the post synaptic neuron is hyperpolarized, the depolarization will bump up the membrane potential but it may not go past threshold.

What i'm now worried about is whether this is proper reasoning for mcat because it seems too much. Too specific.

Was this a question or was there just text saying that?

 

[chiddler]

question. I II III IV type of question. this was one of them.

 

[Morsetlis]

A receptor-ligand interaction on the postsynaptic membrane produces an action potential at the site of interaction.

This is false, because it doesn't produce an action potential it produces a depolarization. Isn't this a bit excessively stringent? Or is this normal usage.

Then again I just remembered summation and this is starting to make more sense...still accepting opinions.

This is not excessively stringent. AP's are initiated as a propagating all-or-nothing wave of depolarization that does not appreciably diminish with distance.

There are GRADED POTENTIALS, especially at sensory receptors, or at the dendrites of axons summon up modulating inputs, that are NOT action potentials. They diminish with distance, and can either depolarize or hyperpolarize the cell membrane. This is how one neuron can inhibit a neuron or a muscle fiber.

If all ligand-receptor binding caused action potentials, how would you inhibit anything?

Furthermore, 1 single ligand-receptor interaction does not cause an action potential. You need to reach Threshold first.