Download 1 st degree

Warmup 1/11/16
What do you already know about skin? Summarize as
best as you can
Objective
To learn the structure and
function of skin
Tonight’s Homework
pp 513: 1, 2, 3, 4
Notes on the Integumentary System
What is this system? This is skin.
A few facts about skin:
- Your skin covers about 2,800 in2
- On average, your skin is 1/8 of an inch thick
- Your skin is your largest organ
Notes on the Integumentary System
Purpose
What’s the purpose of skin? It has a few:
- Protection
Skin protects your body from outside
contaminants like germs, dirt, and disease.
- Sensation
Skin alerts our bodies to outside threats or
obstacles we need to be aware of.
- Heat Control
Our sweat glands help regulate temperature.
In cold weather, it helps keep heat in.
Notes on the Integumentary System
- Excretion
Sweat carries contaminants out along with
heat. You can literally “sweat out” toxins.
- Hormone Manufacture
The skin manufactures a few hormones that
help regulate a few bodily function.
- Absorption
Skin can absorb substances directly, whether
for good or bad. Water and oxygen primarily.
Notes on the Integumentary System
Layers
Epidermis
The epidermis is the uppermost layers of the
skin. The upper levels here are made of dead
cells that
continually fall off.
Stratum corneum
The deepest layer,
the stratum
germinativum,
carries on cell
division and
creates new skin.
Notes on the Integumentary System
Dermis
The dermis is made of connecting tissues, blood
vessels, nerve endings, sweat glands, hair
follicles, and oil glands.
If you cut yourself
and bleed, you’ve
cut down to the
dermis.
Stratum corneum
Notes on the Integumentary System
Subcutaneous Tissue
This isn’t actually part of the skin. Technically,
this is the tissue between the skin and the
underlying muscle.
Fat is usually
found in this layer
to provide
cushioning
between skin and
muscle.
Stratum corneum
Notes on the Integumentary System
Skin Diseases and Disorders
A number of things can go wrong with skin.
Acne
The oil glands – or sebaceous glands – produce
oil to keep your skin from cracking. This oil
secretes into the hair follicles where it’s pushed
to the surface.
As skin sheds, some of it can “glue together”
and block the pore. This causes oil to keep
building up behind the pore.
Notes on the Integumentary System
As this oil buildup continues, bacteria begin to
feed and the site becomes infected. As your
body fights the infection, it creates pus as a
waste product. This pus builds up until the skin
blocking the pore gives way and the pimple
bursts.
Notes on the Integumentary System
Blisters
When injured, plasma – a clear fluid often found
in blood – can leak between layers of tissue,
filling it with fluid. This happens mainly from
friction, but can also be caused by burns or
chemicals. Often this fluid drains when the
blister “pops”. Blisters that fill with blood are
called “blood blisters”.
Notes on the Integumentary System
Burns
Burns come in four levels of
damage.
1st degree:
If the skin gets too hot,
proteins within the cells start
to lose their 3-D shape. This
causes damage to the cells.
Cells lose their ability to
retain moisture and the
nerve endings become extra
sensitive. First degree burns
damage the epidermis only.
Notes on the Integumentary System
2nd Degree
In a second degree burn, the skin blisters as
blood vessels are damaged. The damage here
reaches as low as the papillary dermis at the
root of hair follicles. Strangely enough, this is
often the most painful kind of burn because
nerves have been exposed and dried but not
damaged.
3rd Degree
These burns extend all the way through the
dermis. They’re often painless as they’ve
damaged or destroyed nerves. These burns
never heal fully and may require a skin graft.
Notes on the Integumentary System
4th Degree
These burns reach through the skin into the
subcutaneous tissue and may even damage
muscle or bone. At best, these burns require
amputation. At worst, they can cause death.
First degree burn
second degree burn
(warning! Next two images are disturbing!)
Notes on the Integumentary System
Third degree
fourth degree
Notes on the Integumentary System
Warts
Warts are caused by the human papillomavirus
(HPV). Since they’re viral, they are contagious
and can be caught through open or broken skin.
This virus causes a thickening of the epidermal
layers and infection and enlargement of the
blood vessels beneath.
Exit Question
What is the difference between the epidermis and the
dermis?
a) The dermis contains fat, the epidermis doesn’t.
b) The epidermis contains fat, the dermis doesn’t.
c) The epidermis has nerves and hair follicles.
d) The dermis has nerves and hair follicles.
e) Both have nerves and hair follicles.
f) None of the above