Answer:
End bulb
Step-by-step explanation:
It should be known or understood that the end-bulb is considered to be one of the known small encapsulated bodies which are found or located at the end of sensory nerve fibers. This can be found in the skin, mucous membranes, muscles, and some other areas. It is also called or referred to as the Krause's bulb or corpuscle.
In this case, it the part that is capable of detecting the low frequency of the vibration of the toothbrush.
It can also detect some changes like warmth or cold, depending on the one that is occurring.