Epithelial cells are usually cells located or found outside the body, skin, urinary tract, vessels, cavities, and organs of the body, and have special modifications of their surfaces which depends upon the specific roles they perform and where they are found. However, many types of epithelial cells perform a common function of secretion. Epithelial cells are closely packed together.
Answer: a tiny muscle connected to each hair follicle and the skin. When it contracts it causes the hair to stand erect, and a "goosebump" forms on the skin.