Identify the origin of sympathetic nerve fibres and the location of their ganglia

Options

A. They arise from thoraco-lumbar region of spinal cord and form ganglia just beside the vertebral column
B. They arise from thoraco-cervical region of spinal cord and form ganglia just beside the vertebral column
C. They arise from cranio-sacral region of spinal cord and form ganglia very close to effector organ
D. They arise from thoraco-lumbar region of spinal cord and form ganglia very close to effector organ

Answer

**Step-by-Step Solution:**

1. **Identify the Origin of Sympathetic Nerve Fibers**:
- The sympathetic nerve fibers originate from the thoracolumbar region of the spinal cord. This region includes the first thoracic segment (T1) to the second or third lumbar segment (L2 or L3).

2. **Understand the Function of the Sympathetic Nervous System**:
- The sympathetic nervous system is responsible for the body's 'fight or flight' response during emergencies. It prepares the body to respond to stress by increasing heart rate, dilating airways, and redirecting blood flow to essential organs.

3. **Locate the Ganglia of the Sympathetic Nervous System**:
- The ganglia of the sympathetic nervous system are located just beside the vertebral column. They are positioned ventral (in front) and lateral (to the side) of the spinal cord.

4. **Evaluate the Options Provided**:
- Option 1: Correct - They arise from the thoracolumbar region and form ganglia just beside the vertebral column.
- Option 2: Incorrect - They do not arise from the thoracocervical region.
- Option 3: Incorrect - They do not arise from the craniosacral region.
- Option 4: Incorrect - While they do arise from the thoracolumbar region, the ganglia do not form very close to effector organs; they are beside the vertebral column.

5. **Conclusion**:
- The correct answer is Option 1: Sympathetic nerve fibers arise from the thoracolumbar region of the spinal cord and their ganglia are located just beside the vertebral column.

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