11 Facts About Hair

Hair is a protein filament that grows from follicles found in the dermis.

Hair fibers have a structure consisting of several layers, starting from the outside:.

Hair grows everywhere on the external body except for mucus membranes and glabrous skin, such as that found on the palms of the hands, soles of the feet, and lips.

Hair follows a specific growth cycle with three distinct and concurrent phases: anagen, catagen, and telogen phases; all three occur simultaneously throughout the body.

Andre Walker Hair Typing System is the most widely used system to classify hair.

Hair provides thermal regulation and camouflage for many animals; for others it provides signals to other animals such as warnings, mating, or other communicative displays; and for some animals hair provides defensive functions and, rarely, even offensive protection.

Hair has a sensory function, extending the sense of touch beyond the surface of the skin.

Hair has its origins in the common ancestor of mammals, the synapsids, about 300 million years ago.

Hair is most noticeable on most people in a small number of areas, which are the ones that are most commonly trimmed, plucked, or shaved.

Hair's has been growing her hair since 1973, from the age of 13.

Hair curls were compared to hooks and chains, letters, scorpions, annelids, and polo sticks.