Very cool hairfollicle, So a hair follicle is a small tube-like structure in the skin where a hair grows. It surrounds the root of the hair and is made up of cells and connective tissue. It also contains oil glands and sometimes a tiny muscle (arrector pili) that makes hair stand up.

Tiny tubular structures called hair follicles are found in the skin and are where hair grows. These intricate organs reach deep into the dermis and are linked to auxiliary structures such as arrector pili muscles and sebaceous (oil) glands, which help produce oil to keep hair hydrated and make it stand up in reaction to emotion or cold. Together, these accessory organs protect the skin, promote hair growth, and control body temperature.