1. Integumentary System
Skin, Nails, & Hair

2. Integumentary System: Skin
The largest organ in our body is the skin, which you might not think of as an organ. It covers and protects everything inside your body.
Without skin, people's muscles, bones, and organs would be hanging out all over the place. Skin holds everything together.

3. Integumentary System
Integumentary System consists of the SKIN, HAIR, and NAILS.
The name derives from the Latin integumentum, which means 'a covering.’
The skin covers the body, the hair covers the head and other parts of the body and the nails cover the tops of the fingers and toes.

4. Integumentary System
Look down at your hands for a minute. Even though you can't see anything happening, your epidermis is hard at work. At the bottom of the epidermis, new skin cells are forming.
When the cells are ready, they start moving toward the top of your epidermis.
This trip takes about 2 weeks to a month. As newer cells continue to move up, older cells near the top die and rise to the surface of your skin.
What you see on your hands (and everywhere else on your body) are really dead skin cells.

5. Integumentary System
These old cells are tough and strong, just right for covering your body and protecting it. But they only stick around for a little while. Soon, they'll flake off.
Though you can't see it happening, every minute of the day we lose about 30,000 to 40,000 dead skin cells off the surface of our skin.

6. Integumentary System
So just in the time it took you to read this far, you've probably lost about 40,000 cells.
That's almost 9 pounds of cells every year! But don't think your skin might wear out someday.
Your epidermis is always making new skin cells that rise to the top to replace the old ones.

7. Functions of Integumentary System
1. protection of internal organs/tissues from environment & germs
2. regulates body temperature (sweat & blood flow)
3. excretes (gets rid of) wastes in sweat
4. has nerves to sense environment
5. produces vitamin D in sunlight (UV light)
6. stores fat for fuel & insulation

8. Integumentary System: 3 Layers
The skin has 3 major layers:
1. Epidermis: The layer you can see.
It’s cells thick.
At the Epidermis bottom, new skin cells are formed. The cells move up to the top. This trip takes about 2 weeks to a month.
95% of the epidermis cells work to make new skin cells. The other five percent work to make melanin.

9. Integumentary System: 3 Layers
2. Dermis: (2nd layer): Contains nerve endings, blood vessels, hair follicles, sweat glands, and oil glands.
Contains collagen and elastin, which are tough and stretchy.
Oil glands here secrete (produces) an oily substance (sebum) that spreads over the epidermis to keep it flexible & waterproof.

10. Integumentary System: 3 Layers
3. Subcutaneous layer: Made mostly of fat and helps keep you warm, and absorb shocks. (falling down/banging into something)
Holds your skin to all the tissues underneath it.
This layer is where you'll find the start of hair.

11. Integumentary System

12. Why is skin different colors?
In the epidermis there are cells called melanocytes. They make a substance called melanin (meh-luh-nin). Melanin is a chemical that gives skin its color. It is found in the Epidermis. The darker your skin is, the more melanin you have. When you go out into the sun, these cells make extra melanin to protect you from getting burned by the sun's UV rays. (ultraviolet)

13. Integumentary System: Nails
Nails protect the tips of the fingers and toes.
Nails: are a form of modified hair and grow from nail roots or beds.
These roots are areas of rapidly dividing cells. During cell division, nail root cells are filled with a protein called keratin (which is also what your hair is made of!) and they become tough and plate-like.
Keratin: a protein that helps make your nails tough and plate like.
Found: IN NAILS!

14. Integumentary System: Nails
Yeah, doesn’t hurt…
There are no nerve endings in nails.
That’s why THIS doesn’t hurt!
Unless you cut yourself shaving….that is.

15. Integumentary System: Nails
Nails grow about one-tenth of an inch (2.5 mm) per month.
It takes approximately six months for a fingernail to grow from cuticle to tip.
This lady is crazy! It’s taken her 24 years to grow her nails out!
FUN FACT!: They also grow faster than your toenails do and will grow faster on your dominant hand.

16. Integumentary System: Hair
Each hair on your body grows out of a tiny tube in the skin called a follicle.
Every follicle has its roots way down in the subcutaneous layer.
Hairs are dead cells which are filled with keratin – (same protein in nails).
Hair growth is caused by rapid cell growth at the base of the hair follicle.
The color of hair is determined by the amount of melanin in the skin.

17. Integumentary System: Hair
You have hair follicles all over the body, except on the lips, the palms of hands, and the soles of feet.
There are more than 100,000 follicles on the head. Connected to each follicle in the dermis layer is a tiny sebaceous gland that releases sebum onto the hair.
This lightly coats the hair with oil, giving it some shine and a little waterproofing.

18. Integumentary System: Problems
Your skin knows why you tan—that sunlight is RADIATION, and too much of it can be very damaging.
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.

19. Integumentary System: Problems
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.

20. Integumentary System: 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!

21. Integumentary System: Problems
What do these people have in common?
If you said that
their hair follicles
have fallen out,
then you’re right!
Forms of Male
Pattern Baldness
are known to
affect some women
too!

22. Integumentary System: Problems
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.

23. Integumentary System: Problems
If it’s absolutely driving you crazy, then go see the doc!
And Don’t Worry! EVERYONE gets them!
Even these guys….

24. Review
What are the 3 body parts of the Integumentary system?

25. Review
Skin
Hair
Nails

26. Review
What are the 6 functions of the Integumentary system?

27. Functions of Integumentary System
1. protection of internal organs/tissues from environment & germs
2. regulates body temperature (sweat & blood flow)
3. excretes (gets rid of) wastes in sweat
4. has nerves to sense environment
5. produces vitamin D in sunlight (UV light)
6. stores fat for fuel & insulation

28. What are the 3 layers of skin?
Review
What are the 3 layers of skin?

29. Review
The layer on the outside is called the epidermis. What you see when you look at your skin are really dead skin cells. Ninety-five percent of the cells in the epidermis work to make new skin cells. The other five percent work to make melanin.
The next layer down is the dermis. The dermis contains nerve endings, blood vessels, hair follicles, sweat glands, and oil glands.
The third and bottom layer of the skin is called the subcutaneous layer. It is made mostly of fat and helps your body stay warm and absorb shocks, like if you bang into something or fall down. The subcutaneous layer also helps hold your skin to all the tissues.

30. Review
What is melanin?

31. Melanin gives skin its color
Melanin gives skin its color. The darker your skin is, the more melanin you have. When you go out into the sun, these cells make extra melanin to protect you from getting burned by the sun's UV rays. (ultraviolet)
It also gives color to your hair!

32. What is your hair and nails made up of? (it’s a type of protein)…
Review
What is your hair and nails made up of?
(it’s a type of protein)…

33. Integumentary System: Nails
Nails protect the tips of the fingers and toes.
They are a form of modified hair and grow from nail roots or beds.
These roots are areas of rapidly dividing cells. During cell division, nail root cells are filled with a protein called keratin (which is also what your hair is made of!) and they become tough and plate-like.

34. What problems can happen within your Integumentary System?
Review
What problems can happen within your Integumentary System?

35. Review
Melanoma – from too much tanning
Acne
Hairloss

36. Review
Right now there are over a million dust mites, microscopic critters invisible to the naked eye, on your mattress and pillow, chomping on the dead skin cells that fell off you last night!

37. Integumentary System: Consists of SKIN, HAIR, & NAILS.
6 Functions of the Integumentary System:
1. protection of internal organs/tissues from environment & germs
2. regulates body temperature (sweat & blood flow)
3. excretes (gets rid of) wastes in sweat
4. has nerves to sense environment
5. produces vitamin D in sunlight (UV light)
6. stores fat for fuel & insulation
3 Layers of the Skin:
1. Epidermis: The layer you can see. It’s cells thick.
2. Dermis: (2nd layer): Contains nerve endings, blood vessels, hair follicles, sweat glands, and oil glands.
3. Subcutaneous layer: Made mostly of fat and helps your body stay warm and absorb shocks, like if you bang into something or fall down.
Hair follicles are: DEAD SKIN CELLS WITH KERATIN
Nails are: A form of modified HAIR, and grow from nail roots or beds.
Keratin is: a protein that helps make your nails tough and plate-like.
It is found: IN YOUR NAILS!
Melanin is: Melanin gives skin its color. The darker your skin is, the more melanin you have.
Found?: IN YOUR SKIN