When you think of your hair, you probably think of the hair on
your head. But there's hair on almost every part of your body.
(Some places that don't have hair include the lips, the palms
of the hands, and the soles of the feet.)
Some of the hair on your body is easy to see, like your eyebrows
and the hair on your head, arms, and legs. But other hair, like
that on your cheek, is almost invisible. Depending on where it is,
hair has different jobs. The hair on your head keeps your head warm
and provides a little cushioning for your skull. Eyelashes protect
your
eyes
by decreasing the amount of light and dust that go into them, and
eyebrows protect your eyes from sweat dripping down from your
forehead.
Hair Comes From Where?
Whether hair is growing out of your head, arm, or ankle, it all
rises out of the skin in the same way. It starts at the
hair root
, a place beneath the skin where cells band together to form
keratin (the protein that hair is made of). The root is inside a
follicle
(say:
fah
-lih-kul), which is like a small tube in the skin.
As the hair begins to grow, it pushes up from the root and out
of the follicle, through the
skin
where it can be seen. Tiny blood vessels at the base of every
follicle feed the hair root to keep it growing. But once the hair
is at the skin's surface, the cells within the strand of hair
aren't alive anymore. The hair you see on every part of your
body contains dead cells. That's why it doesn't cause pain
when someone cuts your hair with scissors!
Nearly every hair follicle is attached to a
sebaceous
(say: sih-
bay
-shus) gland, which is sometimes called an oil gland. These
sebaceous glands produce oil, which makes the hair shiny and a bit
waterproof. Sometimes, like during puberty, these glands can pump
out too much oil and a person's hair may look greasy. Time for
a shampoo!
Hair Today, Gone Tomorrow!
You have more than 100,000 hairs on your head, but you lose some
every day. About 50 to 100 hairs fall out each day, while
you're washing your hair, brushing or combing it, or just
sitting still. But don't worry, new hairs are constantly
replacing those that have fallen out.
Each hair on your head grows for about 2 to 6 years. Then it
rests for a few months and finally falls out. It is replaced by a
new hair, which begins to grow from the same hair follicle. This
cycle of hair growing, resting, falling out, and being replaced
helps to maintain just the right number of hairs on your head.
Hair Comes in Many Colors
What kind of hair do you have - black and curly, blond and
straight, or some other combination? Hair color comes from
melanin
(say:
meh
-luh-nun), the substance that gives hair and skin its pigment. The
lighter someone's hair, the less melanin there is. A person
with brown or black hair has much more melanin than someone with
blond or red hair. Older people lose the melanin pigment in their
hair as they age, making their hair look gray or white.
Often, a person's skin color goes with the color of his or
her hair. For example, many blondes have light skin, whereas many
people with darker skin have dark brown or black hair. And
don't forget
genes
(genes are what you inherit from your parents): Usually, a
kid's hair color is determined by one or both parents' hair
color.
When it comes to type, your hair follicles make a difference.
Some hair follicles are structured in a way that produces curly
hair, whereas others send out straight hair. Follicles also
determine if your hair will be thick and coarse or thin and
fine.
Taking Care of Hair
With hair, the main thing is keeping it clean. Some people wash
their hair every day, but others do it just once or twice a week.
It depends on your hair and what kind of things you've been
doing, like exercising or swimming.
When you wash your hair, use a gentle shampoo and warm water.
Lather up using your fingertips, rather than your fingernails. You
might use a conditioner or a shampoo containing a conditioner. This
can take the tangles out or your hair and make it look smooth. But
depending on your hair, it can also make it look flat and oily.
Rinse your hair with plenty of clean water. Dry it gently with a
towel and use a wide-tooth comb to untangle it.
Be kind to your hair - wet or dry - by being gentle when you
comb or brush your hair. Don't yank on knots too hard and
don't wear your ponytails and braids too tight. This can
irritate your scalp. And if you use curling irons or blow-dryers,
be careful and ask for adult help when needed. You don't want
to burn yourself.
Here's an easy way to have great-looking hair: Eat a
healthy diet
. It's not as weird as it sounds. A nutritious diet helps your
body from the inside out!
Updated and reviewed by:
Steven Dowshen, MD
Date reviewed: March 2007
Note: All information is for educational purposes only. For specific medical advice,
diagnoses, and treatment, consult your doctor.
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