So what is it?

Skin and accessory structures arising from it (i.e. hair, glands & nails)

Into the Integumentary system!!!

BIOL 2010 Human Anatomy & Physiology IBIOL 2010 Human Anatomy & Physiology I

What are the functions of the Integ. System?

What are the functions of the Integ. System?

Protection: “Keeps the outside out and the inside in”

Barrier formed by:

• Layers (___________________)

• Chemical barrier (_______________)

• Cell connections (_________________________ see pg. )

When barrier penetrated then ________________ in dermis and hypodermis

Temperature regulation:

______________ in the dermis and hypodermis _______ or ________ to regulate blood flow in skin.

Heat lost via ___________, ___________, ___________ & ___________

OK, so you have more blood circulating through your skin… So what?!?

What are the functions of the Integ. System?

You may have noticed that, on very cold winter days, people’s ears and noses turn red. Can you explain why this happens?

Take 5!!!

Discuss with your neighbor and predict

an answer.

Vitamin D production:Your body depends on _________ (UVB) to transform a precursor of vitamin D… 7-dehydrocholesterol into ________________

The intermediate (cholecalciferol) is converted to active vitamin D (______________) by liver and kidneys.

Vitamin D helps regulate _______ levels.

So how does this relate to skin color?

What are the functions of the Integ. System?

Sensation:

Sensory receptors in dermis and hypodermis allow us to sense…

• __________& _________

• ________

• ________

We’ll discuss these in detail in chpt. 15

What are the functions of the Integ. System?

Excretion:

Small amounts of ____________ ______ products (NH3, Urea etc.) are lost through sweating.

What are the functions of the Integ. System?

3 main layers:_____________Thin layer of _________ ___________ epithelium

BIOL 2010 Human Anatomy & Physiology IBIOL 2010 Human Anatomy & Physiology I

What are the main layers of the Integ. System?

___________Thicker, tough layer of _______ __________ connective tissue and other components

Technically not part of the skin, varies in thickness depending in part on the amount of ___________ present

__________

• Most ___________ layer

• Comprised of stratified squamous epithelium

• Most cells are *_____________ (become filled with keratin)

• Some cells are: *___________ (give skin it’s pigmentation) *___________ (immune cells)

What are the epithelial details?

• Outermost layer sloughs off… takes ___ - ____ days to replace

What are “mites and motes”?

Most of the dust floating in sunbeams, covering the tops of bookshelves etc. is desquamated keratinocytes (i.e. _______ _____ ____)

______ ______ (Dermatophagoides) eat these cells.

House dust allergies are generally Dust mite ______ _______________

5 layers (strata)

_____

________

__________

________

________

Deepest layer, mitosis, pushes new cells upwards

During “histo-prep” cells pull apart… still mitosis

Keratohyalin granules, lamellar bodies release lipids

The cell dies, organelles deteriorate leaving keratin

Thick layer of keratinized (dead) cells that sloughs off

Is the epidermis homogenous deep to superficial?

Some drugs are administered by applying the drug to the skin (ex., a nicotine patch). The drug diffuses through the epidermis to the blood vessels in the dermis. What kind of substances can pass easily through the skin by diffusion? What kind have difficulty?

Take 5!!!

Discuss with your neighbor and predict

an answer.

Thick and Thin skin refers to ________ ______ not dermis or skin

Why are some people so “thick skinned”?

Thick skin

_____ ___: Not all 5 layers present, but hair is!Why are some people so “thick skinned”?

• Contains all the “goodies”

• 2 layers_________

layer_________

layerDermis is primarily what type of tissue?

Consists of _________, _________ ____ and ___________ and _____

What types of fibers?

___________________________

What are the Dermis Details?

2 layersReticular layerPapillary layer

What is the function of the papillae?

What are the Dermis Details?

Epidermis of some skin follows contours of __________ _________ ______.

Is this in thin or thick skin?

How, what, where and why do we have “fingerprints”?

___________ (cleavage) _____

The fibers in the dermis are not arranged ___________ at ________. Greater strength in “lines” due to orientation of ____________ ________.

Surgeons make incisions parallel to tension lines when possible

Are all incisions created equally?

________ (stretch marks)

As the skin is stretched the dermis “ruptures” and forms linear scars (____).

Striae gravidarum & lineae albicantes

Let’s predict the orientation of tension lines based on the direction of striae!

Is the skin equally strong in all directions?

Is the skin equally strong in all directions?

• _________, ______ ____ (____ of body fat) and macrophages• Primarily ______ _________ tissue

• Also called _____________ or ___________ tissue

What are the Hypodermis Details?

___________ glands…

• _________ ______ glands

• _________ ______ glands

Abundant & widespread, mostly H2O, ducts to surface of skin, myoepithelial cells.

Less abundant, found in ______, _____, _____ regions (& faces of men), > conc. Of ______ ______, bacteria breakdown cause rancid smell, ducts to hair follicles.

BIOL 2010 Human Anatomy & Physiology IBIOL 2010 Human Anatomy & Physiology I

What type of glands are in the skin?

__________ glands…

Secrete _________ (oily substance) often into hair follicle (holocrine glands).

Other glands…

____________

____________

What type of glands are in the skin?

Anatomy:_______________

Growth from ________!

Above skinSkin - to matrix

Matrix to papilla

What’s all the fuzz about?

Fetus & newborns

Fine unpigmented hair

Coarse pigmented hair

Types:_______

_______

_______

Texture:Straight

Wavy

Kinky

_________ in cross-section

_________ in cross-section

_________ in cross-section

Colors:

Blonde - Black

Red

White

Varying amounts of _______

___________ pigment

No melanin, ____ in medulla

What’s all the fuzz about?

Predict #3 - pg. 146Marie Antoinette’s hair supposedly turned white overnight after she heard she would be sent to the guillotine.

Explain why you believe or disbelieve this story!

Take 5!!!

Discuss with your neighbor and predict

an answer.

Growth also from ________ and also comprised of dead epithelial cells and _______ _______

What portion of the nail would a physician have to remove to eliminate the nail?

Let’s nail down the anatomy!

Caused by:

__________

____________

• Group of pigments (black, brown, yellowish, or reddish).

• Produced by __________

____________

• O2 transporting molecule in blood (__ makes it red)

• Yellow/orange pigment

What causes differences in skin color?

Abnormal skin

colorations:

• ________

• ________

• ________

• ________

• ________

Cyan = blue

Pallo = sway

Albi = white

Eryth = red

What about abnormal skin colorations?

Burns are ranked based on the severity and the depth of tissue destruction.1st degree:____________ damaged ~red & painful, NO blisters

2nd degree:_________ & some _______ damaged ~red, white or tan, very painful, BLISTERS present

3rd degree (full thickness)_____ _______ ___________ ~black, NO pain, NO blisters

Why are burns some of the most painful injuries?

Have you ever wondered how they measure % of body burned?

They use the rule of 9s.

9

+9 = 189

18 + 18 = 36

18 +18 = 36

1

= 100%

How do you determine the extent of a burn?

_______ _____ forms (we’ll discuss later)

Variety of new cells _________ to damaged area

____________divide rapidly and ________ invade tissue

_______ replaced with other fibers

How do skin wounds heal?

1 2

3 4

Types are identified based on the type of cells that mutate:_____ ___ carcinoma

Least dangerous, start as “shiny” bump, center becomes concave and ulcerus _________ ___ carcinoma

___________

Raised, red, “scaly” & ulcerus, can metastasize

Dark, flat, irregular, most deadly

Is all skin cancer equally dangerous?