In: Psychology
Which of the following correctly describes the sequence of events that occurs once a neuron’s threshold for forming an action potential is reached?
A. Sodium enters the neuron, followed by potassium leaving the neuron.
B. Sodium enters the neuron at the same time that potassium leaves the neuron.
C. Potassium enters the neuron, followed by sodium leaving the neuron.
D. Potassium enters the neuron at the same time that sodium leaves the neuron
Please explain the answer in 200 words or less.
The "threshold" potential of a membrane is the Minimum depolarization needed to operate the voltage gated sodium and potassium channels.
The convergence of ions isn't static however! Ions are streaming all through the neuron continually as the ions endeavor to adjust their concentrations. The cell however keeps up a genuinely reliable negative fixation gradient (between - 40 to - 90 millivolts).
The neuron cell membrane is super penetrable to potassium ions, thus heaps of potassium spills out of the neuron through potassium spillage channels (openings in the cell divider).
The neuron cell membrane is in part penetrable to sodium ions, so sodium iotas gradually spill into the neuron through sodium spillage channels.
The cell needs to keep up a negative resting membrane potential, so it has a pump that pumps potassium once more into the cell and pumps sodium out of the cell in the meantime.
Answer - sodium enters the neuron followed by potassium leaving the neuron