Pick out the incorrect statement ?

Options

A. Myelinated nerve fibres are found in spinal and cranial nerve.
B. Unmyelinate nerve fibre is enclosed by a Schwann cell.
C. In resting stage, the axonal membrane is comparatively more permeable to potassium ion and nearly impermeable to sodium ions.
D. The axonal membrane is permeable to negatively charged proteins presnt in the axoplasm,

Answer

To solve the question of picking out the incorrect statement regarding neural control and coordination, we will analyze each of the provided statements step by step.

### Step-by-Step Solution:

1. **Understanding Myelinated and Unmyelinated Nerve Fibers:**
- **Statement 1:** "Myelinated nerve fibers are found in spinal cord and cranial nerve."
- Myelinated nerve fibers are indeed present in both the spinal cord and cranial nerves. This statement is **correct**.

2. **Examining Unmyelinated Nerve Fibers:**
- **Statement 2:** "Unmyelinated nerve fiber is enclosed by a Schwann cell."
- Unmyelinated nerve fibers can be associated with Schwann cells, but they are not fully enclosed by them as myelinated fibers are. However, this statement is generally considered **correct** in the context that Schwann cells do provide some support.

3. **Analyzing the Resting State of Axonal Membrane:**
- **Statement 3:** "In the resting state, the axonal membrane is comparatively more permeable to potassium ions and nearly impermeable to sodium ions."
- This statement is **correct**. In the resting state, the axonal membrane is indeed more permeable to potassium ions and less permeable to sodium ions.

4. **Reviewing the Permeability of the Axonal Membrane:**
- **Statement 4:** "The axonal membrane is permeable to negatively charged proteins present in the axoplasm."
- This statement is **incorrect**. The axonal membrane is actually **impermeable** to negatively charged proteins. These proteins cannot pass through the membrane, which contributes to the negative charge inside the neuron during the resting state.

### Conclusion:
The incorrect statement is **Statement 4**: "The axonal membrane is permeable to negatively charged proteins present in the axoplasm."

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