A neurologist tests vibratory sense using a 256 Hz tuning fork placed on the ankle. Which sensory receptor is chiefly responsible for transducing this high-frequency vibration?
- A Merkel cell-neurite complex
- B Pacinian corpuscle ✓
- C Ruffini ending
- D Free nerve ending
Correct answer: B. Pacinian corpuscle
Explanation
Pacinian corpuscles are rapidly adapting mechanoreceptors with lamellated capsules tuned to high-frequency vibration, roughly 100 to 300 Hz, and they mediate the sensation tested by a tuning fork. Meissner corpuscles detect lower-frequency flutter around 30 to 50 Hz. Merkel cells and Ruffini endings are slowly adapting and signal sustained pressure and skin stretch respectively, while free nerve endings subserve pain and temperature rather than discrete vibration.
Reference: Kandel Principles of Neural Science, 6th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.