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    what is the difference between potassium/sodium ion pumps, sodium/potassium ion channels and voltage-gated channels?? are they located in the same area. it seems that the same process happens to all of them and which one is it where positive feedback occurs?

    what is the difference between generator potential and depolarisation ?

    i'm confused at the fact that action potentials are not produced in one way where the sodium ions diffuse down their concentration gradient in the sodium ion channel ..etc
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    the Na/K pump is constantly actively transporting Na/K in/out. However, the ion channels are the ones that open/close due to an action potential.
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    (Original post by esmeralda123)
    what is the difference between potassium/sodium ion pumps, sodium/potassium ion channels and voltage-gated channels?? are they located in the same area. it seems that the same process happens to all of them and which one is it where positive feedback occurs?

    what is the difference between generator potential and depolarisation ?

    i'm confused at the fact that action potentials are not produced in one way where the sodium ions diffuse down their concentration gradient in the sodium ion channel ..etc
    They are all located within the axon membrane. However, at resting potential only potassium channels are open as the membrane isn't permeable to sodium ions. However, when an impulse arrives, positive feedback occurs, and the potential difference is reduced ever so slightly to above -55 mV, which is when the voltage dependent gated channels open. Of course, the membrane is now permeable to na + ions and so depolarisation occurs. This causes a positive potential difference and due to this the sodium voltage dependent gated channels close and the corresponding potassium ones open, causing repolarisation and eventually, hyperpolarisation. Generator potential refers to the initial depolarisation required to trigger the wave of depolarisation or to enable saltatory conduction (movement of sodium across the nodes of Ranvier). It is essentially a form of action potential and refers to this process, whereas depolarisation is just a part of this. Tell me if you need any other help, but try to google any terms I mentioned here.
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