What is incorrect about the resting state of neuron ?

Options

A. High concentration of `K^(+)` and negatively charged proteins and low concentration of `Na^(+)` in axoplasm.
B. Axonal membrane is nearly impermeable to `Na^(+)` .
C. Axonal membrane is more permeable to `K^(+)`.
D. Outer surface of axon is negatively charged.

Answer

To determine what is incorrect about the resting state of a neuron, let's analyze the options provided step by step.

### Step 1: Understand the resting state of a neuron
In the resting state, a neuron maintains a specific distribution of ions across its membrane. This is crucial for the generation of action potentials. The key ions involved are sodium (Na⁺) and potassium (K⁺).

### Step 2: Analyze each option
1. **High concentration of K⁺ and negatively charged proteins and low concentration of Na⁺ in exoplasma.**
- In the resting state, the concentration of K⁺ is indeed high inside the neuron (exoplasma), and the concentration of Na⁺ is low. This statement is correct.

2. **Axonal membrane is nearly impermeable to sodium ions.**
- The axonal membrane is relatively impermeable to Na⁺ ions during the resting state. This statement is correct.

3. **Axonal membrane is more permeable to potassium ions.**
- The axonal membrane is more permeable to K⁺ ions compared to Na⁺ ions during the resting state. This statement is correct.

4. **Outer surface of axon is negatively charged.**
- The outer surface of the axon is actually positively charged due to the higher concentration of Na⁺ ions outside the neuron compared to the inside. Therefore, this statement is incorrect.

### Conclusion
The incorrect statement about the resting state of a neuron is **Option 4: Outer surface of axon is negatively charged.**