I’m revising neurology and I’ve come across a confusing concept. To cut to the chase, after hyperpolarization, we will have a whole lot of positive sodium ions inside the cell (which got in during depolarization and got trapped by the inactivation of the voltage gated sodium channels), and lots of positive potassium ions outside the cell (which caused repolarization and then hyperpolarization). After that, the sodium-potassium pump pumps three Na+ out and two k+ in, which somehow restores the membrane potential of the cell, which is more positive than the hyperpolarized state. How on earth does what is essentially the removal of one positive charge (edit: at a time obviously) from the inside of the cell going to raise the membrane potential and make it more positive thus fixing hyperpolarization?
i believe I can explain your question this way,
even though the sodium potassium pump does indeed help change the charge of the membrane, it’s main cause is not changing the whole potential. by changing the concentration of ions in and out of the membrane, it paves the way for other ions to start their path as well and in total with the help of other ions, the potential changes.
hope this clears it up
ok I’ll look further into it. Thanks!
no problems at all! dont worry I don’t think this much details would be asked in the exam. just knowing the structure of hyperpolarization and depolarization would be good to go!