You touched a very rough surface of the sand paper when your___ touchest it this act serves as the __ causing the nerve cells in the fingers stimulate the roughness .the __of the sensory neurons pick the stimulus and send it to the __Of the neurons .then the stimulus becomes impulse and then carried by the __away from the cell body to another neuron. The several neurons pass the impulse until it reaches to the __then to the __the brain__the message and send it back through the __in the finger and the brains will tell you that you are rough surface of a sandpaper