Skin
The skin is the human body’s largest organ.
Recall that an organ is a group of tissues that work together to perform
functions in your body. Examples of other organs include your brain,
heart and lungs.
The skin is the largest organ
in the human body.
For the average adult
human,
the skin has a surface area of
between 1.5-2.0 square
meters (16- 21 feet).
The average square inch of
skin holds 650 sweat glands,
20 blood vessels,
60,000 melanocytes, and
more than a thousand nerve
endings.
Define the parts of the skin diagram.
Give a function for each part
Epidermis Dermis
Follicle
Oil Gland Sweat Gland
Pore
Nerve
Fatty tissue
The skin on your hands and
feet is noticeably different
from that on most other
areas of your body. Unlike
those other areas, the skin
on your palms and soles
doesn't have hair.
When you soak in water,
most of your skin looks
normal while your hands and
feet wind up looking like
wrinkled prunes.
This extra thickness may
also explain why your hands
and feet become wrinkled
when you soak in the tub.
The dead keratin cells
absorb the water so that the
thin surface layer of skin
expands and then wrinkles
We are constantly sweating,
even though we may not notice it.
Sweating is your body's major way of
getting rid of excess body heat.
The amount of sweat produced depends upon our
states of emotion and physical activity.
Sweat can be made in response to nerve stimulation,
hot air temperature, and/or exercise.
Another way in which your hands and
feet are different is that both the palms
and soles have unique patterns of
ridges, also called fingerprints and
footprints.
The middle layer of skin, the dermis,
connects to the epidermal layer through
many papillae, which are tiny fingerlike
projections of connective tissue.
Fingerprints and footprints result when
double rows of papillae occur. These
ridges have purposes other than helping
forensics experts to solve crimes; they
help you to grab on to objects, and they
help to keep your skin from ripping
Skin Layers

The outer layer of your skin is the
epidermis, it is found thickest on the
palms of your hands and soles of your
feet (around 1.5mm thick)

If skin is severely damaged then it may try
to heal by forming scar tissue. Scar tissue
is not the same as normal skin tissue, it
often appears discolored and lacks sweat
glands and hair.

A large amount of the dust in your home
is actually dead skin.

Polar bears have both white and
transparent (see through) fur, their skin is
actually black.

Amphibians such as frogs have unique
skin. Rather than drinking water, frogs
actually soak it into their body through
their skin. They also use their skin to
absorb around half the air they need.
Frogs have very special skin! They don't
just wear it, they drink and breathe
through it.
Fun Facts
Frogs don't usually swallow water like we
do. Instead they absorb most of the
moisture they need through their skin