There are two electrodes placed at a distance of 4.5cm and it takes 1.5ms for current to be propagated along the nerve from one to another electrode. The velocity of nerve conduction is ?
## **Core Concept**
The velocity of nerve conduction can be calculated using the distance between two electrodes and the time it takes for the current to propagate from one electrode to the other. This is a fundamental concept in neurophysiology, specifically in the assessment of nerve function through electrophysiological studies.
## **Why the Correct Answer is Right**
To calculate the velocity of nerve conduction, we use the formula: velocity = distance / time. Given that the distance between the electrodes is 4.5 cm and the time taken for current propagation is 1.5 ms, we can substitute these values into the formula. First, ensure that the units are compatible; here, they are (centimeters for distance and milliseconds for time). The calculation is velocity = 4.5 cm / 1.5 ms = 3 cm/ms. To convert this into meters per second (m/s), we remember that 1 cm = 0.01 m and 1 ms = 0.001 s. Therefore, 3 cm/ms = 3 * (0.01 m / 0.001 s) = 30 m/s.
## **Why Each Wrong Option is Incorrect**
- **Option A:** This option is incorrect because, without calculation, we cannot assume its correctness, and upon calculation, it does not match our derived value.
- **Option B:** Similarly, this option does not align with our calculated velocity of nerve conduction.
- **Option D:** This option suggests a much slower velocity than what we calculated.
## **Clinical Pearl / High-Yield Fact**
A normal nerve conduction velocity ranges approximately from 50 to 100 m/s for motor nerves and 50 to 90 m/s for sensory nerves. Our calculated value of 30 m/s seems low but let's ensure we're comparing apples to apples; the question seems to have provided a straightforward calculation rather than a clinical scenario necessitating comparison to normative data.
## **Correct Answer:** . 30 m/s