A<unk>  is part of the skin that grows<unk>  by packing old cells together. Attached to the<unk>  is a sebaceous gland, a tiny sebum-producing gland found everywhere except on the palms, lips and soles of the feet. The thicker density of<unk> , the more sebaceous glands are found.
Also attached to the<unk>  is a tiny bundle of muscle fiber called the arrector pili that is responsible for causing the<unk>  and<unk>  to become more perpendicular to the surface of the skin, and causing the<unk>  to protrude slightly above the surrounding skin.  This process results in goose bumps (or goose flesh).  Stem cells are located at the junction of the arrector and the<unk> , and are principally responsible for the ongoing<unk>  production during a process known as the Anagen stage.
The average growth rate of<unk> s on the scalp is .04 cm per day.
Certain species of Demodex mites live in the<unk> s of mammals (including those of humans) where they feed on sebum.
Hair follicle
Inner cell mass
Callus
Mammary gland
Papaveretum
Fundic glands
Episclera
Skin appendage