Which statement about the autonomic nervous system is true ?

Options

A. The sympathetic division is afferent, and the parasympathetic division is efferent.
B. Each pathway in the autonomic nervous system includes the neurons , and the neurotransmitter of the first neuron is acetylcholine.
C. The cell bodies of many sympathetic preganglionic neuron are in the brain stem.
D. The cell bodies of most parsympathetic post ganglionic neurons are in or near the thoracic and lumber spinal cord.

Answer

To determine which statement about the autonomic nervous system (ANS) is true, we can analyze the characteristics and functions of its divisions: the sympathetic and parasympathetic nervous systems.

### Step-by-Step Solution:

1. **Understanding the Autonomic Nervous System**:
- The ANS is a part of the peripheral nervous system that controls involuntary bodily functions. It is divided into two main divisions: the sympathetic and parasympathetic nervous systems.

2. **Identifying the Sympathetic and Parasympathetic Divisions**:
- The sympathetic division is often referred to as the "fight or flight" system, preparing the body for stressful situations.
- The parasympathetic division is known as the "rest and digest" system, promoting relaxation and energy conservation.

3. **Analyzing the Statements**:
- **Statement 1**: "The sympathetic division is afferent and the parasympathetic division is efferent."
- This is incorrect. The sympathetic division is efferent (it sends signals away from the central nervous system), while the parasympathetic division is also efferent.
- **Statement 2**: "Each pathway in the autonomic nervous system includes neurons and neurotransmitters, with the first neuron using acetylcholine."
- This is correct. In the ANS, the first neuron (preganglionic neuron) releases acetylcholine.
- **Statement 3**: "The cell bodies of the main sympathetic pre-ganglionic neurons are in the brain stem."
- This is incorrect. The cell bodies of sympathetic pre-ganglionic neurons are located in the spinal cord, specifically in the thoracic and lumbar regions.
- **Statement 4**: "The cell bodies of the most parasympathetic post-ganglionic neurons are near the thoracic and lumbar spinal cord."
- This is incorrect. The cell bodies of parasympathetic post-ganglionic neurons are located in the brain stem and sacral region of the spinal cord.

4. **Conclusion**:
- The true statement about the autonomic nervous system is **Statement 2**: "Each pathway in the autonomic nervous system includes the neurons and neurotransmitters, with the first neuron using acetylcholine."