Vibration sensation (low frequency) is mediated by:
## Core Concept
Vibration sensation, particularly low-frequency vibration, is a type of mechanoreception that allows individuals to perceive vibrations through their skin. This sensation is crucial for proprioception (awareness of body position and movement) and tactile perception. The detection of vibrations involves specific mechanoreceptors in the skin.
## Why the Correct Answer is Right
The correct answer, , involves the **Pacinian corpuscles**. These are rapidly adapting mechanoreceptors found in the dermal layer of the skin and are responsible for detecting changes in pressure and vibration. Pacinian corpuscles are particularly sensitive to high-frequency vibration but also respond to low-frequency vibration to some extent. However, their large size and myelinated nerve fiber allow for quick transmission of signals, making them suitable for detecting vibrations.
## Why Each Wrong Option is Incorrect
- **Option A:** - This option is incorrect because while Meissner's corpuscles are mechanoreceptors, they are more sensitive to light touch and changes in texture rather than vibration.
- **Option B:** - This option is incorrect as Merkel's discs are slowly adapting mechanoreceptors involved in sustained pressure and texture perception, not vibration.
- **Option D:** - This option is incorrect because Ruffini's corpuscles detect skin stretch and are involved in the perception of slip of skin, not vibration.
## Clinical Pearl / High-Yield Fact
A key clinical point is that vibration sense is often tested in a clinical setting to assess the integrity of the dorsal columns of the spinal cord. Loss of vibration sense (or pallesthesia) can indicate a lesion in these pathways. A simple bedside test involves using a vibrating tuning fork placed on a bony prominence.
## Correct Answer: . Pacinian corpuscles