Page 84 - How It Works - Book Of Amazing Answers To Curious Questions, Volume 05-15

How do suntans

develop? Find out how our skin reacts to being

exposed to the Sun

edical professionals continue to warn melanocytes in our skin to react by producing melanoyctes’ DNA, which can lead to a deadly
us about the dangers of exposing our more melanin pigment. Melanin is the pigment form of skin cancer known as melanoma.
Mskin to too much sunlight. In spite of responsible for our skin’s colour and it protects Recent science suggests the process of tanning
this, many of us still spend too long sunbathing the cells by absorbing UV radiation that would has addictive qualities. An experiment using
in the hope of achieving the even bronzing that otherwise damage skin cells. People with mice showed that as well as producing melanin,
so many celebrities fl aunt. naturally darker skin have more melanin and so UV radiation produced pleasure chemicals
When we expose our skin to strong sunlight or are inherently better protected against sunlight. called endorphins, which are also produced
a sunbed, the UV radiation we absorb prompts Nevertheless, excessive UV exposure damages after a person ingests addictive drugs.

The tanning process
Learn the locations of important structures
within the skin that play a role in creating a tan

The Sun
The Sun produces UVA, UVB
and UVC light, but the UVC is
mostly blocked out by the
Earth’s atmosphere.

UVB
These short waves cause the
melanocytes to initiate the
production of melanin. UVB
also promotes the synthesis
of vitamin D.

UVA
The long waves
have a direct
Melanin effect on our
This pigment skin’s melanin,
browns when it creating a natural
absorbs UVA light. tan by oxidising
It also increases in it brown.
size and then
surrounds each
skin cell.
Horny layer
This layer of
Melanosomes dead skin cells is
These are produced thickened when
within the it’s exposed to
melanocytes and UV light, helping
contain the enzyme to form a
tyrosinase, which protective layer.
synthesises melanin.

Melanocytes
These are specialised The epidermis
skin cells. They are Our skin cells are in a
responsible for the continuous 30-day cycle, in
production of which they are constantly
melanosomes and can produced and replaced.
send them to the This is why suntans
surrounding skin cells. eventually fade.

84 How It Works