Final answer:
Vibration is the correct technique to apply to nerve trunks and centers, as it effectively stimulates the tactile receptors, specifically the Pacinian corpuscles, which respond to deep pressure and vibration.
Step-by-step explanation:
The student is inquiring about which type of massage technique should be applied to nerve trunks and centers. The correct answer is D. Vibration. This is because nerve endings like the Pacinian corpuscles, which are found in the deep layers of the skin such as the dermis or subcutaneous tissue, are responsive to deep pressure and vibration.
The use of vibration at these sites can stimulate the nerve trunks and centers effectively due to their sensitivity to such mechanoreceptor input. Other receptors like Merkel cells (type I cutaneous mechanoreceptors) and Ruffini corpuscles (type II cutaneous mechanoreceptors) respond to different types of stimuli, emphasizing the specificity of tactile receptors in our skin. Friction massage involves applying firm pressure and circular movements to the skin, which can help stimulate blood flow and break up scar tissue or adhesions in the surrounding tissues.