what is the arrector pili muscle made up of
1 Arrector Pili Muscle-This is a tiny muscle that attaches to the base of a hair follicle at one end and to dermal tissue on the other end. 2  In order to generate heat when the body is cold, the arrector pili muscles contract all at once, causing the hair to stand up straight on the skin.lick image to enlarge. A basic understanding of skin anatomy is important when explaining the process of skin biopsy. Each component of the skin plays a role in its daily function, therefore every component is a source of vital information that can be captured and assessed with a skin biopsy.