When an impulse passes , the membrane is depolarized and the charge of the cell is

Options

A. outside positive and inside negative
B. inside positive and outside negative
C. both sides have zero potential
D. both sides are electronegative

Answer

**Step-by-Step Solution:**

1. **Understanding Resting Membrane Potential**:
- In a resting state, the neuron is polarized. The inside of the neuron is negatively charged relative to the outside, which is positively charged. This is due to the differential permeability of the membrane to ions, primarily potassium (K+) and sodium (Na+).

2. **Depolarization Trigger**:
- When a stimulus is applied to the neuron, it causes the membrane to become permeable to sodium ions (Na+). This is a crucial step in the generation of an action potential.

3. **Ion Movement**:
- As the sodium channels open, Na+ ions rush into the cell. This influx of positively charged ions causes the inside of the cell to become less negative (or more positive) compared to the outside.

4. **Change in Membrane Charge**:
- During depolarization, the inside of the neuron becomes positively charged while the outside becomes negatively charged. This is the opposite of the resting state.

5. **Conclusion**:
- Therefore, when an impulse passes and the membrane is depolarized, the charge of the cell is inside positive and outside negative.

**Final Answer**: Inside positive, outside negative.

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