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 ________________________________________________

Melanin absorbs UV light and prevents it from reaching deeper layers

› 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

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

The skin appendages include cutaneous glands, hair, and nails.

Why are these a part of the integumentary system and not something else?

• _____________________ 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

Hair

Nails

Quick Review

Are the skin appendages (cutaneous glands, hair, hair follicles, and nails) found in the dermis or epidermis? Justify your answer.

• The hair follicle is composed of the

(outer) _______________ sheath and

(inner) ___________________sheath.

• The follicle is slanted unless the

_____________________________

muscles are contracted

• 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 __________________________________________________.

• 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.

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.