In an auto accident the driver suffers complete sectioning of several anterior (ventral ) roots of spinal nerves . What would be the result of such a lesion to the regions supplied by those spinal nerves ?

Options

A. loss of sensation
B. loss of sensation and motor activity
C. loss of temperature and pain sensation
D. loss of motor activity

Explanation

To solve the question regarding the consequences of complete sectioning of several anterior (ventral) roots of spinal nerves, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Anatomy of Spinal Nerves**:
- The spinal nerves consist of two roots: the dorsal (posterior) root and the ventral (anterior) root.
- The dorsal root is responsible for carrying sensory information from the body to the spinal cord.
- The ventral root is responsible for carrying motor commands from the spinal cord to the muscles.

2. **Identifying the Impact of Sectioning the Ventral Roots**:
- The question specifies that there is a complete sectioning of the anterior (ventral) roots of the spinal nerves.
- Since the ventral roots are responsible for motor functions, cutting these roots will disrupt the transmission of motor signals.

3. **Consequences of the Lesion**:
- With the ventral roots severed, the affected regions of the body will lose motor activity because the signals that stimulate muscle contraction will not reach the muscles.
- However, sensory functions will remain intact because the dorsal roots, which carry sensory information, are not affected by the sectioning of the ventral roots.

4. **Conclusion**:
- The result of the lesion to the regions supplied by those spinal nerves will be a loss of motor activity in the muscles innervated by the affected spinal nerves. Sensation will remain unaffected.

### Final Answer:
The result of the complete sectioning of several anterior (ventral) roots of spinal nerves will be a **loss of motor activity** in the regions supplied by those spinal nerves.

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