I'm sorry, what? I have no idea where you're coming from Maybe this is what you're looking forI thought I understood action potentials but now i"m confused...
I learned that the sodium potassium pump restores the resting potential in axons by removing 3 sodium ions and adding 2 potassium ions back into the cell interior.
But wouldn't that make the interior of the cell more negative? How would that help if the cell is hyperpolarized?
And also, which ion channels are open and which are closed? Am I right in saying that the ligand gated potassium channels are open in the postsynaptic terminal, but all voltage gated channels are closed in the axon? If that's true, then ions can only freely diffuse back and forth in the postsynaptic terminal? So the sodium-potassium pump would also have to maintain ion gradients there as well as in the axons?
Sorry about all the questions! I'm probably making this more complicated than it should be
I think you're overthinking this a bit. The sodium-potassium pump kinda works to "replenish" the the Na+ and K+ ions that have flown down their electrochemical gradients. I suppose you could say that they work at all times, but their only significant role is in establishing the neuron's RMP. Once you start getting into action potentials, you're really just looking at the voltage-gated channels in the axon membrane; for graded potentials, primarily ligand-gated channels in the dendrites.Oh! I see now
So the resting potential is restored just by closing potassium channels, not the pump? I guess I'm confused about when the pump works. Does it work at the resting potential? Would that imply that leak channels are open at rest?
Haha yeah, I meant dendrites! So the purpose of the postsynaptic potential is just to trigger or inhibit the production of action potential at the axon hillock? Does the pump work there as well?
Thanks so much! Maybe it's just me, but some of the online resources contradict each other, which might explain my confusion
I don't think anyone knows yet; the earliest event notification I've seen was after state. Integumentary system is definitely one of them though...Does anyone know what systems are tentatively scheduled for C division next year?
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