Transcript Lesson 5 – The Skin

Lesson 5 – The Skin

The skin covers and protects the body
from injury, infections, and water loss.
The skin also helps regulate body
temperature, eliminate wastes, gather
information about the environment and
produce vitamin D.
The Body’s Tough Covering
The skin protects the body by forming a
barrier that keeps disease-causing
microorganisms and harmful substances
outside the body.
 The skin also keeps important substances
inside the body like plastic wrap.

Protecting the Body
Many blood vessels run throughout the
skin. When you become too warm, these
blood vessels enlarge and the amount of
blood that flows through them increases.
 These changes allow heat to move from
your body into the outside environment.
 As perspiration evaporates from your skin,
your skin is cooled.

Maintining Temperature
Perspiration contains dissolved waste
materials that come from the breakdown
of chemical during cellular processes.
 Thus your skin is also helping to eliminate
wastes that come from the breakdown of
proteins that are eliminated during
perspiration.

Eliminating Wasted
The nerves in your skin provide
information about such things as
pressure, pain and temperature.
 Pain messages are important because
they warn you when something in your
surroundings may have injured you.

Gathering Information
Vitamin D is important for healthy bones
because it helps the cells in your digestive
system to absorb calcium in your food.
 Your skin can get the Vitamin D it needs
to function from sunlight.

Producing Vitamin D
The skin is organized into two main
layers, the epidermis and dermis.
 The epidermis is the outer layer of the
skin . The epidermis does not have nerves
or blood vessels. That is why you do not
feel pain from very shallow scratches.

The Epidermis and Dermis
Cells deep in the epidermis produce
melanin, a pigment or colored substance
that gives skin its color.
 The more melanin in your skin, the darker
it is.
 Exposure to sunlight stimulates the skin
to make more melanin.
 Melanin production also help to protect
the skin from burning.

The dermis is the inner layer of the skin.
 The dermis contains nerves and blood
vessels. It also contains sweat glands,
hair, and oil glands.
 Sweat glands produce perspiration, which
reaches the surface through openings
called pores.
 Strands of hair grow within the dermis in
structures called follicles.

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Three simple habits can help you keep
your skin healthy.
◦ Eat a healthy diet
◦ Keep your skin clean and dry
◦ Limit your exposure to the sun.
Caring for your Skin