More about hair

Some of the points that follow may surprise you and will tell you more about hair:

• The scalp carries around 1,000 hairs per 1.5 square centimetres.
• On average, a person has between 90,000 and 120,000 hairs.
• Blond hair is generally the most numerous on the scalp, followed by light brown and dark brown hair.
• Red hair is generally the least dense, which is not apparent because of its greater thickness.
• Human hair is the strongest natural fibre there is. The thicker the hair, the greater its tensile strength.
• Each hair follicle can produce a certain number of hairs at once, following the various stages of the hair growth cycle.
• Those with thick hair do not have more follicles than others; the thickness comes from the fact that more hairs on average grow from each follicle.
• Eyelashes and eyebrows have a function similar to the guttering of a house: they protect the eyes from running water.
• Underarm and pubic hair has two functions: to prevent the skin from rubbing, and to diffuse and hold the scent of the apocrine glands. This function begins at the same age as the development of pubic hair and of the beard, that is, at sexual maturity.
• Hair also has its own muscle, called the arrector pili, which raises the hair when a person is cold and produces the "goose bumps" look of the skin. Fear and danger can also cause this reaction.
• Brown hair is the most common in the world. Red hair accounts for only about 1% of the world's population, making it the rarest. Blond hair accounts for close to 5% of the world's population.
• Hair can grow anywhere on the body, except the palms of the hands, the soles of the feet, the lips and the mucous membranes.
• Hair is more elastic than people think: its length can stretch by more than 30% when wet.
• Hair falls out daily at a rate of 50 to 150 hairs a day, shedding being part of its growth cycle.
• After bone marrow, hair is the fastest-growing tissue in the body.
• Hair is made mainly of keratin, which is also found in the outer layer of the skin and in the nails.