Which term refers to the physician tapping on a surface to determine the underlying structure?

• A. Percussion
• B. Auscultation
• C. Inspection
• D. Palpation

Answer: (A)

Percussion is the technique used when a clinician taps on a surface of the body to listen to the sounds produced and infer what lies beneath. By striking a finger placed on the patient (the pleximeter) with another finger or a small hammer (the plexor), different underlying tissues generate different sounds. Air-filled areas, like healthy lungs, typically produce a resonant sound, while solid or fluid-filled areas, such as the liver or a mass, yield dullness. This method helps estimate organ size and detect abnormalities like excess fluid, air, or masses. It’s distinct from auscultation (listening with a stethoscope), palpation (feeling with the hands for tenderness or texture), and inspection (visual examination).