Here's why:

* Meissner's corpuscles, Pacinian corpuscles, and Merkel cells are all types of sensory receptors found in the skin. They are responsible for detecting different types of touch, pressure, and vibration.

* Arrector pili are tiny muscles attached to hair follicles. When they contract, they cause the hair to stand on end, creating "goosebumps". This is a reflex response, primarily related to temperature regulation and not touch sensation.

Let me know if you have any other questions!