Number of spinal nerves in human

Options

A. 31 pairs
B. 32 pairs
C. 12 pairs
D. 37 pairs

Answer

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks for the number of spinal nerves in humans. Spinal nerves are part of the peripheral nervous system and connect the spinal cord to various parts of the body.

2. **Identifying the Total Number of Spinal Nerves**: In humans, spinal nerves are categorized into pairs based on their origin from the spinal cord.

3. **Categorization of Spinal Nerves**:
- **Cervical Nerves**: There are 8 pairs of cervical nerves (C1 to C8).
- **Thoracic Nerves**: There are 12 pairs of thoracic nerves (T1 to T12).
- **Lumbar Nerves**: There are 5 pairs of lumbar nerves (L1 to L5).
- **Sacral Nerves**: There are 5 pairs of sacral nerves (S1 to S5).
- **Coccygeal Nerve**: There is 1 pair of coccygeal nerves (Co1).

4. **Calculating the Total**: To find the total number of spinal nerves, we add the pairs:
- 8 (cervical) + 12 (thoracic) + 5 (lumbar) + 5 (sacral) + 1 (coccygeal) = 31 pairs of spinal nerves.

5. **Choosing the Correct Answer**: From the options provided:
- Option 1: 31 pairs (Correct)
- Option 2: 32 pairs (Incorrect)
- Option 3: 12 pairs (Incorrect)
- Option 4: 37 pairs (Incorrect)

6. **Conclusion**: The correct answer to the question is 31 pairs of spinal nerves in humans.