Grace stepped on a tack in the carpet which is a ___________…

Grace stepped on a tack in the carpet which is a ___________ detected by a ___________. This information is sent to a _______________, the brain, where it is determined that the skin on the foot is out of normal range. The brain sends signals to _____________ that cause physiological responses to jerk the foot up.  Obj 1.6/ 1.7