INTEGUMENTARY SYSTEM GUIDED NOTES
Name: ___________________________ Class: ________
Components

___________________________

___________________________

___________________________
Functions
1. _________________________________________
›
›
›
From ________________________________________________________

Barrier of tough, keratinized cells

Pain receptors warn body of possible damage
From ________________________________________________

Unbroken surface

Acidic secretions inhibit bacterial growth

Phagocytes ingest foreign material
From ________________________________________________

›
From _________________________________________________

›
Melanin absorbs UV light and prevents it from reaching deeper layers
Pain receptors warn body of possible damage
From _________________________________________________

Keratin and other substances keep skin fairly waterproof
2. _____________________________________________
How does the skin help us cool down?
______________________________________________________________________________
______________________________________________________________________________
How does the skin help us warm up?
______________________________________________________________________________
______________________________________________________________________________
3.
________________________________________________
The sweat glands excrete metabolic wastes (urea, uric acid), salt, and lactic acid (in addition to water)
4. _________________________________________________
When UV light hits the skin, modified cholesterol molecules are converte into vitamin D.
Skin Structure
The skin is composed of two layers:
1) Epidermis – made of __________________________ tissue
2) Dermis-
made of __________________________ tissue
Epidermis Strata
The epidermis has multiple ________________or layers.
Only the deepest layer contains actively dividing cells and melanocytes.
Why?
___________________________________________________
___________________________________________________
As new cells form, older cells are pushed towards the surface
As the cells are pushed away from the blood supply, they ______________
and flatten.
The most superficial layer is made of the dry, _____________________
membranes of skin cells
Epidermis Cells
1) ___________________________________________________
›
Keratin-producing cells
›
Keratin is the protein that makes skin tough and waterproof.
›
Most abundant cell in epidermis by far!
2) __________________________________________________
›
Melanin-producing cells
›
Melanin is the brown-black pigment that is largely responsible for skin, hair, and eye color
›
Melanin absorbs UV light to product DNA from damage
›
Found only in deepest layer of epidermis
Skin Color
 Major determinants of skin color
›
Amount / type ______________________
›
Amount ____________________ (from fruits and veggies)
›
Amount ______________________ in blood
 Adaptive significance
›
Trade off between _______________________ and __________________________
Dermis
The dermis is made of what tissue? _________________________________________________________
___________________________________ tissue cushions and binds things together. In the skin, the _______________
tissue holds together lots of different elements:
•
Exocrine glands
•
Hair follicles
•
Nerves and sense receptors
•
Blood vessels
The collagen and elastic fibers of the dermis give skin its strength and elasticity
Burn Classification
First degree burns
 __________________________________________________________________________

Signs: ______________________________________________________________________


Example: most sun burns
Will heal on own
Second degree burns
 ____________________________________________________________________________

Signs: _______________________________________________________________________

Will heal with care
Third degree burns

____________________________________________________________________________

Signs: _______________________________________________________________________

Skin will not heal; grafts must be done
How do burns disrupt homeostasis?
Burned skin can no longer carry out its functions
Most critically, skin can no longer


___________________________________________________________________

______________________ and _______________________ can cause kidneys to shut down and
patients to go into shock due to low blood volume.

Happens almost immediately, unless fluids are replaced.
__________________________________________________________________

________________________ becomes a major concern within 2-3 days following severe burns.
Other complications

Burned skin cannot _________________________. ______________________becomes a problem.

3rd degree burns cannot __________________________________. Scar tissue forms. Scar tissue does a poor
job of performing the functions of skin, and if the scar tissue is extensive, mobility may be affected.
Skin Appendages
The skin appendages include cutaneous glands, hair,
and nails.
Why are these a part of the integumentary system and
not something else?
Vocab Check!
What is cutaneous?
What is an exocrine gland?
Cutaneous Glands
1) _______________________(oil) glands
•
Found everywhere except palms of hands and soles of feet
•
The ducts mostly _________________________________
•
Produce oily product called __________________
•
Functions:
•
•
__________________________________________
•
__________________________________________
Become much more active in adolescence
2) Sweat (__________________________) glands
•
•
_____________________ glands produce sweat (water, salt, urea, lactic acid)
•
Duct lead to ___________________________
•
Functions
•
_____________________________________
•
_____________________________________
•
_____________________________________
___________________________ produce a milky secretion fully of fatty acids and proteins.
•
Duct leads _________________________
•
Function: __________________________
Make a Venn Diagram comparing the three types of cutaneous glands. You may work with a partner.
Hair Follicle
•
The hair follicle is composed of the
(outer) _______________ sheath and
(inner) ___________________sheath.
•
The follicle is slanted unless the
_____________________________
muscles are contracted
Hair
•
Hair can be divided into the _______________ (part outside of
body) and ______________ (inside body)
•
Hair is produced by division of ______________________
epithelial cells in the hair bulb, but as the cells are pushed away
from the bulb they begin to die.
•
Like the outer layer of the skin, the hair shaft is composed of
__________________________________________________.
Nails
•
Produced by the cells of the
_____________________________
•
The nail root, closest to the nail
matrix, is living
•
The outer part, like the hair and
skin, consists of
___________________________
cells.
Quick Review
Are the skin appendages (cutaneous glands, hair, hair follicles, and nails) found in the dermis or epidermis?
Justify your answer.
What did we talk about today that you don’t see on this diagram?
Common Types of Skin Cancer
There a three main types of skin cancers, defined by the type of cell from which they arise.
______________________________________ – arise from the basal edge of the epithelial tissue.
_______________________________________ – arise from the keratin-producing cells in the middle of the
epithelial tissue.
_______________________________________ – arise from the melanin-producing cells at the basal edge of
the epithelial tissue
Excess ___________________________________ increases the risk of each of these cancers
Basal cell carcinoma

Most common form of skin cancer

Affects ~2.8 million people in the US each year

Slow-growing and rarely fatal
Squamous Cell Carcinoma

Second most common form of skin cancer

Affects ~700,000 people in the US each year

Grow and invade surrounding tissue quickly

<5% are fatal
Melanoma

Third most common skin cancer

Affects ~76,000 people in the US each year

Quickly metastasizes (spreads) to blood vessels and lymph nodes – which allows it to spread to other locations in
the body

Fatal in more than 10% of cases
Melanoma may be the least common type of skin cancer, but it is by far the most deadly.
Moreover, while rates of most other cancers are declining in the US (due to a reduction of smoking) melanoma rates are
increasing.