| Hair Facts Your body is covered by around five million hairs, with between 100,000 to 150,000 on an average head.
The hair shaft is seen above the skin surface and is mostly made up of keratin, hard dead protein. Nails are also made of Keratin as are birds feathers and claws.
The Keratin in a hair shaft is built up in three layers:-
Medulla - This central part may not be present
Coretex - Makes up most of the hair, contains hair pigment called melanin.
Responsible for hairs strength and curl. Its regular molecules also make it very flexible.
Cuticle - Formed by overlapping layers which look like scales.
When magnified younger scales nearest the skin are smoother and unbroken. Hair conditioning products work at this layer to prevent weathering.
When cold the erector muscle contracts making the hair stand on end. This is also a defense mechanism to make you look larger to an enemy.....works for cats anyway!
The sebaceous gland produces sebum, a natural oil which acts like a conditioner.
The hair bulb lays within the base of hair follicle. It is a living structure containing actively growing cells which eventually produces a long fine cylinder of hair. Cells in the hair bulb divide faster than in any other part of your body.
Hair growth;- Hair grows at about 1cm a month or 0.3mm a day. When the weather is hot hairs grow faster, good news if you live in the Highlands!
The hair cycle is split into phases;- Anagen (growth) followed by Catagen (regression) and then Telogen (resting). When repeated the anagen stage sheds the hair from the previous cycle.
Anagen - active hair growth,
Scalp hairs grow for 2 to 7 years
Thigh hair grows for 1 to 2 months
Eyebrow and eyelash hair grow for 1 to 6 months.
Catagen - normally only 2 weeks, the follicle rests, no new cells are produced within the bulb. The follicle contracts and the hair shaft is eventually ejected from the bulb
Telogen - the resting phase lasts about 4 months before awakening to form a new hair in the anagen phase pushing out the hairs released from hair bulb in the old cycle.
Leg hair Telogen phase can last from 3 to 6 months
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