Hyponatremia is a condition in which the sodium in the blood is too low. uncontrolled spasms, which are sudden, involuntary contractions of muscles, are among the symptoms of hyponatremia. why do they occur? a. sodium is needed to generate an action potential. b. sodium makes up most of the myelin sheath. c. sodium is the signaling molecule that transmits impulses across a synapse. d. sodium controls voluntary movement, and potassium controls involuntary movement

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. :)