How would you explain the charge changes that occur in a neuron during the messaging process?
The correct answer and explanation is:
In a neuron, the charge changes during the process of sending a message are a result of electrical signals called action potentials. These signals are generated and propagated along the neuron, allowing communication between neurons.
Initially, a neuron is at rest, and the inside of the cell is negatively charged compared to the outside. This resting potential is about -70 millivolts. This difference in charge is maintained by ion pumps, which actively transport sodium (Na+) ions out of the cell and potassium (K+) ions into the cell, creating a concentration gradient.
When a neuron receives a signal, a stimulus causes some of the sodium channels to open. Sodium ions rush into the cell due to both the concentration gradient and the electrical potential. This influx of positive ions makes the inside of the neuron less negative, causing depolarization. If the depolarization reaches a certain threshold, usually around -55 millivolts, it triggers an action potential.
Once the action potential begins, the membrane potential rapidly shifts. More sodium channels open, and sodium ions flood into the cell, further depolarizing the neuron. At the peak of the action potential, around +30 millivolts, the sodium channels close, and potassium channels open. Potassium ions move out of the cell, repolarizing the membrane and restoring a negative charge inside the neuron.
After the action potential passes, the neuron undergoes a refractory period, where the ion channels reset, and the resting membrane potential is reestablished. This is done by the sodium-potassium pump, which restores the balance of sodium and potassium ions. The entire process ensures that signals travel quickly and efficiently along the neuron, allowing for rapid communication in the nervous system.