Get your body system books!!. Integumentary System. the WHAT?. That stuff! Your SKIN!. Review Time!. Structure = a part of the body Function = a job to do Homeostasis = balance in the body Stimulus = something the body senses Response = how the body reacts to the stimulus.
That stuff! Your SKIN!
…yeah…can’t wait for the DISORDERS, too
you become dramatically smaller,
you’ll be left with your full-sized
organ)!#1 Integumentary System Overview
Do you ever think of your skin as an organ? Probably
not very often, if ever.
But it IS an organ, and one of
your largest! Take your skin off,
and you’d weigh 5 to 10 pounds less,
but more importantly, you wouldn’t
last very long.
Your skin has a BRUTAL job. It’s your only major organ
on the OUTSIDE of your body, so it has to deal with
conditions that would totally overwhelm your heart or
kidneys or any other organ. Because of this constant
attack, your skin cells die & are replaced every month!
Your integumentary system is any surface covering for
the body. We’ll focus on the major ones (skin, hair, nails).
Technically, your integumentary system also deals with
the tissues that line the inside of your organs—like the
lining of your throat down your esophagus, and so forth.
But we’ll focus on your outside skin this year.
Let’s see what your skin does for ya…
1. protection from environment & germs
2. regulates body temperature
3. excretes (gets rid of) wastes in sweat
4. has nerves to sense environment
5. produces vitamin D in sunlight
(vitamin D is vital in helping
your bones absorb calcium)
Those are some very important functions, eh?
Now, let’s see the structures that make all these functions
happen. There’s a lot—be warned!
layer#5 STRUCTURES of the Integumentary System
Your skin is the largest organ of the body. It has a lot of
important jobs, which we just saw, and is made of two main
i. sweat gland –excretes waste
& cools body
ii. sebaceous (oil) gland.
you need SOME oil on
your skin to keep it healthy.
iii. hair follicles which poke up
out of the surface of the skin
iv. blood vessels including small
arteries, veins & capillaries
(are you writing these structures in
the blanks on the back of your page?)
v. muscles – tighten skin & raise
hairs (to get warmer)
vi. fat – we all have a layer of
fat (called the subcutaneous
layer) underneath our dermis
that insulates the body.
vii. nerves – send signals to the
brain, letting it know what
you’re touching or is touching
you. You can sense pain,
pressure, hot, and cold.
(I’ll have to draw nerves in the diagram)
Whew! Your skin is JAM-PACKED with all sorts of stuff.
You look at it from the outside, and it looks so plain and
simple. That’s on purpose. The outside has to deal with
all sorts of harsh conditions, so it’s all dead skin cells,
ready to flake off.
…and you know the result of all that flaking, right?
Your hair and nails cover your body, too. Your nails are
made of a special skin-like protein called keratin, which
happens to be what your hair is made of, too.
Your hair and nails are made of special cells that are thick
and hardened. Why can you cut, chew, and chop them off?
They are dead tissues with no working nerves to signal pain.
This could get nasty! I don’t…
Uh, sorry, Joe. This isn’t a democracy.
You lose. But we CAN spare you from
some of the more rare and gross skin disorders that affect
a few unlucky people. For now, get ready to hit the beach!
Joe likes the beach. Who doesn’t???
All that playing gets tiring, so Joe lays out on a towel for
…and he lays in the sun…
…and bakes in the sun…
…and roasts in the sun…
…and he finally gets up to go home.
He can tell he is BURNED to a near-crisp.
The next morning, it’s obvious to Joe what he’s done.
His friends joke with him the
whole day—making fun, slapping
his sore back, repeating “should’ve
put on your sunscreen” a billion
…and after a week of soreness
and peeling, Joe will be fine again.
But Joe better not fall into a
pattern of burn/heal/burn/heal
over his lifetime. All that sunlight
can really fill him with regrets
Your skin knows more than a lot of people’s brains—that
sunlight is RADIATION, and too much of it can be very
In the presence of the stimulus of sunlight, your skin responds
by making extra melanin – the pigment that gives your skin its
color. This helps bounce sunlight off your skin to prevent it
from absorbing too much radiation. This is how & why you tan.
But if you overwhelm your skin’s ability
to SLOWLY make melanin, it will absorb
a lot of energy, burn (temporary pain),
but most importantly, could set you up
for possible future problems.
Too many times of allowing your skin to be damaged by the
Sun can lead to a condition called melanoma. Melanoma is
a dangerous skin cancer that could be fatal if allowed to
spread to other organs. Protect yourself! Wear sunblock.
Don’t obsess over your tan. Watch
your freckles & moles for any
danger signs. Protect yourself!
What do these people have in common?
If you said that
their hair follicles
have fallen out,
then you’re right!
Forms of Male
are known to
affect some women
Boy, the teenage years can be rough on the skin. Puberty
hits and pimple breakouts flare up. You experiment with
creams and medicated pads that you get at the store, but
what really works? Everyone’s different, so it’s really hard
to say, but if nothing seems to work, you might consider a
visit to the dermatologist.
Acne is really just bacteria-
infected hair follicles.
The bacteria love skin oil,
and when a sebaceous gland
clogs up, they’ll go crazy.
If it’s absolutely driving you
crazy, then go see the doc!
Integumentary System stopped
working? Let’s review the
functions to see.#18 Review
How does the Integumentary System help maintain
Stimulus : Response
Bug crawling on you : nerves send signals, making you aware
It’s hot : sweating
It’s cold : goosebumps
Standing in sunlight : tanning
The End !