Consider the following statements sympathetic nervous system is characterised by
1. Acetylcholine as neuro secretion
2. Fight of flight activities
3. Longer preganglionic fibres
4. Non-medullated postganglionic fibres
5. Arising from thoracic-lumbar portion

Options

A. 1, 2 and 3
B. 2, 4, and 5
C. 2 and 4
D. 1, 3 and 5

Answer

To solve the question regarding the characteristics of the sympathetic nervous system, we will analyze each statement one by one:

### Step-by-Step Solution:

1. **Statement 1: Acetylcholine as neurosecretion**
- The sympathetic nervous system primarily uses norepinephrine as its neurotransmitter at the postganglionic synapse, while acetylcholine is primarily associated with the parasympathetic nervous system. Therefore, this statement is **incorrect**.

2. **Statement 2: Fight or flight activities**
- The sympathetic nervous system is well-known for its role in the "fight or flight" response, which prepares the body to respond to stressful situations. This statement is **correct**.

3. **Statement 3: Longer preganglionic fibres**
- In the sympathetic nervous system, the preganglionic fibers are actually shorter compared to the postganglionic fibers. This statement is **incorrect**.

4. **Statement 4: Non-medullated postganglionic fibres**
- The postganglionic fibers of the sympathetic nervous system are indeed non-myelinated (non-medullated). This statement is **correct**.

5. **Statement 5: Arising from thoracic-lumbar portion**
- The sympathetic nervous system originates from the thoracic and lumbar regions of the spinal cord (T1 to L2). This statement is **correct**.

### Conclusion:
Based on the analysis:
- **Correct Statements**: 2, 4, and 5
- **Incorrect Statements**: 1 and 3

Thus, the correct answer is **Option B: 2, 4, and 5**.

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