National Physical Therapy Examination (NPTE) Practice Exam

Which structure is responsible for the sensation of pressure and vibration?

1. Pacinian corpuscles

2. Krause end bulbs

3. Golgi tendon organs

4. Free nerve endings

The correct answer is: Pacinian corpuscles

Pacinian corpuscles are specialized sensory receptors located deep in the skin and in certain other tissues. They are particularly adept at detecting pressure and vibrations due to their unique structure, which features multiple layers that function like a series of concentric rings. This layered design allows Pacinian corpuscles to respond rapidly to changes in pressure and vibration stimuli. When pressure is applied, the fluid dynamics within the corpuscle cause the layers to shift, ultimately triggering a sensory response. In contrast, Krause end bulbs are primarily involved in the sensation of cold and are not specifically responsive to pressure and vibration. Golgi tendon organs are located within tendons and are sensitive to the tension in the muscles, rather than pressure or vibration. Free nerve endings are the simplest type of sensory receptors and are associated with pain and temperature sensations rather than specifically detecting pressure or vibration. Thus, the structure that is distinctly responsible for sensing pressure and vibration is indeed the Pacinian corpuscles.