Why Do Boys Have Nipples?

your child
H E A LT H
Why Do
Boys Have
Nipples?
We answer your kid’s toughest
body questions. BY KAREN SPRINGEN
C
Kids are naturally
curious about their
body!...!and other
people’s too.
62 November 2010 Parents
THAYER ALLYSON GOWDY.
hildren are famous for asking about bodily
quirks, but moms don’t always have answers. For
instance, do you know why boys have nipples?
George Holcomb, M.D., surgeon-in-chief at Children’s
Mercy Hospitals & Clinics, in Kansas City, Missouri, says
that in the womb, both boys and girls have breast tissue
and nipples. Later, in response to estrogen, teenage girls
develop breasts—so they can eventually breastfeed. Boys
don’t get that same estrogen surge, so their nipples stay
flat. Explain that in terms your kid can understand when
he asks. Read on for answers to other head-scratchers.
your child
H E A LT H
Why Do Some of Us Have
Innies and Others Have Outies?
WHAT TO TELL YOUR KID The belly button (or navel) is
actually a scar on the abdomen, created when a newborn’s
umbilical cord is detached from his mommy. Most people
have innies—and whether or not a person develops one is
determined in the womb, explains Brad Warner, M.D.,
Ph.D., a pediatric surgeon at St. Louis Children’s Hospital.
In the early months of pregnancy, when a baby is very
small, its intestines must develop outside of its body. As
the baby grows larger, the intestines coil up and move
back inside through a hole where the belly button will
later be. The muscle walls under the belly button then
grow together to close the gap; if they seal tight, the
baby gets an innie.
WOW! WHO KNEW?
Sometimes, notes
About one out of every ten
Dr. Warner, the muscle
people has an outie, and
walls don’t quite close
they occur more commonly
all the way, and the
among premature and
baby ends up with
African-American babies.
an outie.
Why Do Baby
Teeth Fall Out?
WHAT TO TELL YOUR KID Baby teeth
begin to loosen and fall out around
the time most kids start elementary
school—age 6 or 7—in order to
make space inside the mouth for
our larger, permanent teeth to
grow in, says Parents advisor
Burton Edelstein, D.D.S, M.P.H,
professor at Columbia University
College of Dental Medicine, in
New York City. Still, our baby teeth
serve an important purpose during
childhood: They not only allow us
to chew the food we need to
stay healthy, they’re essential for
developing speech—as well as for
helping to shape our jaw and facial
bones as they grow and develop.
WOW! WHO KNEW?
Baby teeth usually fall out in
about the same order that they
initially erupted: the two
bottom-front and top-front
teeth first, then the lateral
incisors, followed by the
molars and canines, with the
upper canines last to come in.
64 November 2010 Parents
Getting a
little info
helps kids
feel confident.
What’s a Birthmark?
WHAT TO TELL YOUR KID Birthmarks are blemishes that develop on
the skin before a baby is born or shortly afterward, says Parents advisor
Lawrence F. Eichenfield, M.D., a pediatric dermatologist at Rady Children’s
Hospital and Health Center, in San Diego. Red birthmarks are made up of
extra blood vessels close to the skin’s surface. The most common kind,
telangiectatic nevi (or stork bites), are pinkish in color and flat, while infantile
hemangiomas (also known as strawberry marks) are soft, raised, and bright red.
Still other birthmarks are caused by extra pigment in the skin; a few of the most
common types include moles,
WOW! WHO KNEW?
café au lait spots—patches
Stork bites typically disappear
of skin that are light brown and
within six to 12 months, while
flat—and congenital dermal
strawberry marks and Mongolian
melanocytosis (bluish marks
spots usually take several years to
known as Mongolian spots,
go away. Moles and café au lait
which are most common in
spots do not fade with age.
babies with darker skin).
What Is Snot For?
WHAT TO TELL YOUR KID As
gross as it might
look, snot is produced by special cells in our
nose to help keep us healthy. This sticky
substance (along with the tiny hairs in our
nostrils), traps dust, allergens, and even
germs, preventing them from being inhaled
into our lungs, explains Dr. Holcomb. The
secretions also keep our nose lubricated so
the skin doesn’t get too dry or become
irritated as we breathe in and out.
WOW! WHO KNEW?
When we get sick,
our body goes
into overdrive,
producing extra
mucus to help flush
away bad bacteria,
which is why we get
a runny nose when
we have a bad
cold or the flu.
H E A LT H
Why Do People
Wear Glasses?
WHAT TO TELL YOUR KID Ideally,
an eyeball’s shape should be
perfectly round, like a marble, but
not everyone’s eyes turn out that
way. According to pediatric
ophthalmologist Dean Fiergang,
M.D., of Baltimore, when the
shape of the eye is too short from
front to back, a person ends up
farsighted (meaning it’s easy
to see things far away, but
everything appears blurry close
up). On the other hand, if the eye
is too long from front to back, a
person will be nearsighted (able
to see just fine close up but
unable to focus on stuff that’s far
away). Glasses and contact lenses
bend and focus light rays so that
people with these vision problems
can see clearly all of the time.
WOW! WHO KNEW?
As we get older, the lenses
of our eyes become harder,
which makes it more
difficult to focus—that’s
why so many more adults
wear glasses than kids do.
Why Does Daddy
Have Hair on His
Chest and Toes?
WHAT TO TELL YOUR KID It’s likely
a holdover from our early ancestors,
who needed hair for survival, says
William Leonard, Ph.D., professor
of anthropology at Northwestern
University, in Evanston, Illinois. A
hairy body may have looked scary
to predators and attractive to
females—and it probably helped
our ancestors stay warm.
WOW! WHO KNEW?
People whose families come
from northern areas tend to
have more body hair than
those whose families come
from warm places. The hair
helped in cold climates.
your child
Why Do Some
People Have Dark
Skin While Others
Have Light Skin?
WHAT TO TELL YOUR KID A
person’s skin color is determined
by the amount and type of
pigment (called melanin) in the
skin, says Dr. Eichenfield. Darker
skin, which contains more melanin,
helps in sunny places because it’s
less likely to burn and become
cancerous—so people whose
ancestors come from warmer
regions, like Africa or Southeast
Asia, tend to have darker coloring.
WOW! WHO KNEW?
It’s harder for dark skin to
produce bone-strengthening
vitamin D in response to the
sun, so people with a dark
complexion are especially
likely to need a supplement.
Why Do Some
People Wear
Braces?
WHAT TO TELL YOUR KID Over the
past 100,000 years, humans’ jaws
have been growing smaller
because, unlike our prehistoric
ancestors, we eat mostly soft,
cooked foods that require less
force (and a smaller mouth) to
chew, says Dr. Leonard. But we
continue to develop the same
number of grown-up teeth (32 in
all)—and squishing ’em all into a
reduced-size mouth means they
often come in crooked. To
straighten their smile and help
prevent future health problems,
many people wear braces.
WOW! WHO KNEW?
People used to wait until all
their permanent teeth had
grown in (around age 12 or
13) to get braces, but newer
research suggests that
earlier treatment may
actually be more effective.
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