arrector pili.
arector pili muscle
The root of each hair follicle is connected to the small arrector pili muscles are small muscles attached to hair follicles in mammals. Each arrector pili muscle has a bundle of smooth muscle fibers which attach to the follicular units which have nerves.
The arrector pili muscles makes the hairs on your arm stand on end.
The Arrector Pili muscle
arrector pili
erector pili
arrector pili muscle
arrector pili
the arector pili muscle.
Goosebumps are caused by little muscles called the arrectores pilorum (the hair erector muscles). Contraction of these muscles elevates the hair follicles above the rest of the skin. And it is these tiny elevations we perceive as goose bumps. Source: http://www.medicinenet.com/script/main/art.asp?articlekey=6842
erector pili