| Special Hair Fact File
2301/ Hair is the fastest
growing tissue in the body, second only to bone marrow. 35
metres of hair fibre is produced every day on the average
adult scalp. The current thinking about the cause of male
pattern baldness is that certain hair follicles produce an
enzyme called 5-alpha reductase. This enzyme then converts
the male hormone testosterone circulating in the blood into
dihydrotestosterone or just simply DHT. DHT has a harmful
effect on the follicles causing them to shrink. Dermatologists
call this shrinking process miniaturization. A miniaturized
follicle can no longer produce a healthy hair.
2302/ The average scalp
has 100,000 hairs. Redheads have the least at 80,000; brown
and black haired persons have about 100,000; and blondes have
the most at 120,000. (That is more than a thousand hairs in
each square inch!)
2303/ Hair grows in three
cycles. The first is the growth cycle followed by the resting
cycle and then finally the fall-out cycle. A full, thick,
healthy head of hair is due to a rate of hair growth that
is equal to or greater than the resting and fall-out cycles.
2304/ The most common
form of hair loss, Androgentic Alopecia, or male pattern baldness,
is experienced by 50-80% of all Caucasian men.
2305/ The number of Chinese
males affected are half of there Caucasian counterparts while
African Americans have a lower incidence of the condition
as well. For women androgenetic alopecia occurs to between
20-40% of the general female population.
2306/ If you are a man
between the ages of about 20 to 45 and you start to loose
scalp hair, then the chances are 95 per cent certain that
you are experiencing male pattern baldness.
2307/ It is estimated
that over 50 million men and 25 million women in the United
States suffer from hair loss. There are many reasons for hair
loss including heredity, stress, illness and diet/nutrition,
just to name a few. Heredity being by far the most important.
2308/ Hair is composed
of three concentric layers. The outermost is the cuticle,
which is made up of thin overlapping cells like shingles;
the next is the cortex, made of many elongated cells; and
in the centre is the medulla, with its rectangular-shaped
cells. To form a new hair, the papilla sends a signal to the
immature cells in the bulge, directing them to migrate toward
the papilla. These cells are triggered by the papilla to divide
and mature. The new hair eventually grows up beyond the surface
of the skin.
2309/ Hair is composed
primarily of proteins (88%). These proteins are of a hard
fibrous type known as keratin.
2310/ Hair consists mainly
of keratin, which is also responsible for the elasticity of
fingernails. A single hair has a thickness of 0.02-0.04mm,
so that 20-50 hair fibers next to each other make one millimeter.
Hair is as strong as a wire of iron.
2311/ The organisation
of keratin within its cortex allows it to resist a strain
of up to about a hundred grams. A lock of 100 hairs can thus
withstand a weight of 10 kilograms. Meaning that an average
head of 120,000 hairs could cope with 12 tons, if the scalp
were strong enough!
2312/ Keratin is the
essential component of hair. It is a protein formed by the
combination of 18 amino acids, among which cysteine deserves
special mention, being rich in sulphur and playing an important
role in the cohesion of the hair.
2313/ We are born with
all our hair follicles. Some are programmed to grow pigmented
hair (as on our scalp) up to 3 feet in length. One hair grows
approximately 0.3 mm a day.
2314/ Healthy hair has
an average lifetime of 2-6 years. After a rest period of three
months the single hair falls out, and a new fiber starts to
grow out of the bag. The lifetime depends on circumstances
and the person, too. The lifetime of hair is responsible for
the maximum of hair length you can have. Waist length hair
takes about 6 years to grow out from a short hair cut, periodic
trims included. If your hair has a lifecyle of 2 years, you
will never achieve a nice waist length mane.
2315/ Human beings have
about one million and four hundred thousand hairs on their
body, with about four hundred and fifty thousand of them to
be found above the neck. These hairs include about one hundred
thousand hairs on the head and about thirty thousand hairs
taken up by moustaches, beards, or whiskers.
2316/ The greyish appearance
of hair is only in fact a kind of optical illusion, produced
by the mixture of coloured hair with white hair. The French
expression "pepper and salt hair" gives a good indication
of what this means. It is therefore obvious that the hair
appears increasingly grey as the percentage of white hairs
increases.
2317/ Hair is actually
dead material when it leaves it's root - otherwise it would
hurt very much when your hairdresser works with his scissor.
2318/ Cleopatra used
a mixture of horse teeth, bear grease, burnt mice and deer
marrow in her attempt to cure Julius Caesar's baldness (it
didn't work). Hedgehog urine was also thought to be beneficial.
2319/ The diameter of
a strand of hair ranges from 1/500 to 1/140 of an inch. In
terms of texture, blond hair is the finest, while black hair
is the most coarse.
2320/ Hairs on the scalp
grow about 1/100 of an inch per day, or one inch every three
months. Hair will be replaced at least 12 times during a normal
life span. Hair never grows on the palms and soles. These
are the only areas with no hair follicles.
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