A ton of people don’t realize how important sodium is to the body! Before an action potential (and when a dendrite is triggered by a presynaptic neuron) , Na+ ions have to rush into the the intracellular space (inside the cell), which causes the charges in the extra cellular space and intracellular space to become flipped (less positive inside, more positive outside.) This causes an entire chain reaction down the axon and the membrane of the neuron!
To sum it up, the first this that will happen is the Na ion channels open, and rushes inside, polarization’s in both intracellular and extracellular space flop, Na channels snap shut, K ions channels open and K ions move back outside the cell. There’s obviously way more to it! CrashCourse on YouTube helped me through my physiology course, so I definitely recommend checking them out. :)
(a). Sodium is needed to generate an action potential.
Explanation:
Action potentials are generated when different ions move across the membrane of neurons. Sodium ions are responsible for depolarization during action potential by moving inside the cell through sodium channels.
When sodium ions are low in blood (hyponartremia), it shows dangerous effects on action potentials due to inhibition of normal cycle as sodium ions are not sufficient to depolarize the membrane.
