intro to skin and the integumentary system body membranes and the skin

I N T R O T O S K I N A N D T H E I N T E G U M E N TA RY S Y S T E M

BODY MEMBRANES AND THE SKIN

BODY MEMBRANES: 2 TYPES

• Functions (overall)—Predict first! Write down in your notes!• Cover body surfaces• Line body cavities• Form protective and lubricating sheets around organs

• Epithelial membranes and connective membranes• Types classified by their tissue makeup

QUESTION:

• What are the 4 types of tissues?

TYPE #1: EPITHELIAL MEMBRANES

• AKA covering and lining membrane• Contains both epithelial tissue and connective

tissue• Since it contains more than 1 type of tissue, what could

these membranes be considered as?• Organs!

• Contains 4 sub-categories

EPITHELIAL MEMBRANE: CUTANEOUS• Cutaneous membranes• AKA your skin!• “dry” membrane and

exposed to air• Stratified squamous

epithelium (epidermis) PLUS dense connective tissue (dermis)

• Protection

QUESTION:

• What does “epi” mean?a) Belowb) On top ofc) Within

EPITHELIAL MEMBRANE: MUCOUS• Mucous Membrane• Lines all body cavities

open to the exterior • Respiratory• Digestive• Urinary• Reproductive tracts

• “wet” membrane with secretions of mucous or, in the case of the urinary system, urine

• Most have stratified squamous epithelium OR simple columnar epithelium PLUS loose connective tissue

• Function: protection, lubrication, secretion, absorption

THINK-PAIR-SHARE

• Give 1 similarity and 1 difference between cutaneous and mucous membranes• WRITE THIS IN YOUR NOTES!

EPITHELIAL MEMBRANE: SEROUS• Serous Membranes

(serosa)• Lines body cavities closed to

the interior• Heart• Lungs• Abdominal organs

• Simple squamous epithelium PLUS areolar connective tissue (loose connective tissue) with serous fluid in between.

• Function: produce lubricating fluid that reduces friction

A QUICK NOTE ABOUT SEROSA....• It ALWAYS comes in 2 layers• Visceral (inner) and parietal (outer) layers

• Visualize:

• There is fluid in between the two layers to allow for the membranes to easily side past one another • Think about the organs that are constantly in motion• Structure RELATES to function!

THINK-PAIR-SHARE

• Name 1 similarity and 1 difference between mucous and serous membranes• WRITE THIS IN YOUR NOTES!

CONNECTIVE MEMBRANE: SYNOVIAL

• Synovial Membranes• Soft aerolar

connective tissue• NO epithelial tissue

• Found in joints• Provide a smooth

surface and lubricating fluid

• Cushions organs moving against one another

• Also form small sacs called bursae

QUESTION:

• Which of the following contains both connective AND epithelial tissue?a) Serous membranesb) Synovial membranec) Cutaneous membrane

THINK-PAIR-SHARE

• Give 1 similarity and 1 difference between serous and synovial membranes• WRITE THIS IN YOUR NOTES

STOP!

• Worksheet about membranes• Fill in the table and color the pictures!• With the table, be general when it comes to tissue types

• Make study materials:• Make a graphic organizer, flashcards, start rewriting your

notes• I will be around to check what you have made. This is your

ticket out the door!

SUMMARIES

• These people need to write me a summary about cell division (found in you book)• 5th:• Aunna, Annika, Zak, Erika, Jasmin, Monica, Maria, Simona

• 7th: • Larry, Marissa, Shelby, Courtney, Dakota, Landon, Caleb,

Jessica

WARM UP/REVIEW

• Create a web of the body membranes (be general)

SKIN!

• Cutaneous membrane• Basic functions--predict first! (write down in your

notes!• Protection • From mechanical damage (bumps), chemical damage,

bacteria, UV, thermal damage, desiccation

• Heat retention• Excretion of urea and uric acid• How?

• Sweat! (keep in mind that that is the same type of stuff that is in our urine.....)

• Synthesize vitamin D

STRUCTURE OF THE SKIN• Split up into 2 parts:• Epidermis• Epithelial tissue

• Dermis• Connective tissue

• The dermis and epidermis are firmly connected, but can separate if subjected to rubbing (friction) or a burn• Fluid can then accumulate

between the two layers and form a.....• BLISTER!

JUST AN FYI

• If you get a blister, you should NOT pop it!• The fluid within is a

protective layer because there is delicate skin that is being formed underneath the blister

• If you pop your blister, you will just irritate it more, put yourself at risk for infection, and limit your footwear possibilities

EPIDERMIS

• Split up into 5 zones known as strata

TRUE OR FALSE

• The epidermis has great access to blood supply to supply it with a ton of nutrients.• HINT: think about the tissue that composes the epidermis

DEEP TO SUPERFICIAL• All epidermal cells are keratinocytes• Keratinocytes contain keratin• A protein that makes cells hard so they are resistant to

damage and desiccation

• Stratum Basale• Cells have most adequate nourishment• Why?

• Lies closest to the connective tissue layer (dermis); epidermis is avascular

• Constantly undergoing cellular division and the daughter cells are pushed upward (superficial), away from the nutrients

• Stratum Spinosum• Cells take on a spindley apprearance• Develop desmosomes (what were those things again??)

• Stratum Granulosum• Keratin is packed into little “packets” or granules

DEEP TO SUPERFICIAL

• Stratum Lucidum • Cells flatten, become very keratinized (hardened), and

die• Appear to be clear when looked at under a microscope• Think: What does it mean to be “lucid”?

• Stratum Corneum• Amounts for ¾ of epidermal cells thickness• These are shinglelike dead cells that are shed on a

regular basis• Essentially sacks of keratin

LET’S COME UP WITH A MNEMONIC

• Take a few minutes to come up with a mnemonic with your partners to help you remember the layers of the skin

• Mnemonic example: My Very Eccentric Mother Just Served Us Nosehairs• Mercury, Venus, Earth, Mars, Jupier, Saturn, Uranus,

Neptune• Apparently, Pluto isn’t a planet anymore

MNEMONICS

Bottom to Top

• Brithany,• Stop• Going• Late to • Class

Top to Bottom

• Crazy• Lobsters• Gobble• Salmon• Butter

WHY DO WE LOSE CELLS FROM THE STRATUM CORNEUM?

1. These cells are the farthest away from the nutrient source

2. Keratin limits nutrient entry

QUESTION:

• What would happen if there was too much keratin OR the stratum corneum wasn’t easily lost?• Think-pair-share: write your prediction on the dry erase

board

DISEASE: HARLEQUIN ICHTHYOSIS• Congenital disease• You are born with it

• Caused by thickening of keratin layer; stratum corneum builds up• Causes cracked skin and “scales” that

can crack and inhibit movement• These people have a huge risk of

bacterial infections getting into their skin

• http://www.youtube.com/watch?v=dNOjs6NBgOM

OTHER CELLS

• Melanocytes• Found in the stratum

basale• Produce melanin• Causes there to be

pigment• Function: protect cells

from UV damage• Natural sunscreen!

melanocyte

PREDICT• Why do we tan?• Put your prediction in your notes

TANNING• When the skin is exposed to sunlight, it

stimulates the melanocytes to produce more melanin• More melanin=more protection of cells from UV damage

• Freckles and moles are patches of concentrated melanin

QUESTION:

• Why are different races different colors?• Talk with your partner and write a prediction on the white

board

WHY ARE THERE DIFFERENT SKIN COLORS?

• Things to consider:• Melanin protects from UV damage• We still need UV to synthesize Vitamin D (makes bones

strong)

• Equatorial regions (think Africa and Mexico) have direct, intense sun• Primary concern is protecting stratum basale from damaging

UV rays• What do you think about skin cancer prevalence?

• Europe does not have such direct sun• We need the sun/UV rays for vitamin D• Less melanin so we can soak up the sun to get that vitamin D,

but we have an increased risk of skin cancer

QUESTION:

• What if the melanocytes did not produce any melanin?

ALBANISM

• A genetic disorder caused by a defunct enzyme responsible for helping the melanocytes produce melanin

• The skin appears white or very pale and usually have pale blue eyes• Also typically have poor vision

because melanin also helps in eye development

PREDICT

• What do you predict the skin cancer frequency is among people suffering from albanism?• Think-pair-share

WARM UP

• Draw a picture that shows why there is an increased cancer risk in lighter-skinned people

SOCIETAL CONSEQUENCES• People with albanism typically face social and

cultural challenges• Many cultures around the word have developed beliefs

regarding people with this disorder

• Tanzania and Burundi: rise in witchcraft-killings and body parts sold to witchdoctors• It is also thought in some African cultures that relations

with an albanistic woman can cure a man with HIV

• Some ethnic groups and geographical areas have an increased susceptibility to albanism• Ironically, these groups are places where people with

albanism are the most discriminated

• http://www.youtube.com/watch?v=zd7RRr5Eubg

PREDICT

• Vitamin D is important for having strong bones• Our milk is “fortified” in vitamin D• What you would happen if you were vitamin D deficient?

DISEASE: RICKETS

• “bendy” bones • Usually occurs when

we do not get vitamin D• people who live in

upper latitudes (Europe, Canada) and have dark complexions are especially at risk

IN A NUTSHELL....

• You have 2 options:1. You will get skin cancer if you are exposed to the sun2. You will get rickets from staying out of the sun

STOP!

• Make a model of the cell using dried beans• Each bean represents cells in a particular layer

WHEN YOU HAVE FINISHED YOUR BEANS…..

• Create some study materials• Make some flashcards• Make a graphic organizer (I think a web might be nice…..)• Color-code your notes• Write some test questions• Draw some pictures in the margins

DERMIS

• Your “hide”• Strong, stretchy, holds you together• 2 major regions• Papillary region• Reticular layer

DERMIS: PAPILLARY LAYER

• Uppermost dermal layer• Contains capillaries• Nutrients!• Question: which layer of

epidermis does it feed?

• Houses receptors• Pain, touch

• Uneven surface • Can be arranged in definite

patterns that are genetically determined• Provide for grip• What does this sound like?

STOP

• Look at your fingerprints! Use pencil lead.• Question:• The papillary layer is ___________ to the stratum basale

a) Superficialb) Deepc) Whodee-whattin?

RETICULAR LAYER

• Deepest skin layer• Sits atop a layer of adipose tissue• What is another word for adipose tissue?

• Contains:• Blood vessels,• Sweat/oil glands• nerves

• Major protein: collagen• Responsible for the toughness of the dermis; holds the

cells together• “skin glue”

• Keeps skin hydrated

QUESTION

• Why do we get wrinkles?• When we get older, we produce less collagen so our skin

becomes less elastic • The adipose tissue in our face decreases

QUESTION:

• What would happen if there was a deficient amount of collagen within the skin?• Write a prediction on the white board

DISEASE: DYSTROPHIC EPIDERMOLYSIS BULLOSA (DEB)

• Caused by a mutation in the gene responsible for making collagen• Skin is extremely fragile• http://

www.youtube.com/watch?v=yJqe40_x-TA

HENNA VS TATTOOS

• We all know that tattoos are permanent.• Henna tattoos only last for a

few days or weeks.• PREDICT:• What layer of the skin is affected by

henna and real tattoos?

LET’S MAKE A DIAGRAM!!!

DRAW A PICTURE

• Make a simple drawing in your notes of the epidermis and dermis• Be sure to show each layer of the epidermis AND the

dermis

DRAW A PIC OF THE SKIN

APPENDAGES OF THE SKIN

• Include cutaneous glands, hair and hair follicles, and nails

• Mostly contained within the reticular dermal layer

APPENDAGES: CUTANEOUS GLANDS

• All are exocrine glands• They release their secretions onto the cell surface

• formed by the cells in the stratum basale• Are later pushed down until they reside in the dermis

• 2 types:• Sebaceous glands• Sweat glands

SEBACEOUS (OIL) GLANDS• Found everywhere except

on palms of the hands and soles of the feet

• Ducts usually empty into hair follicle

• Produce sebum• Mixture of oily substances and

fragmented cells• Keeps skin soft, moist, and

prevents hair from becoming brittle

• Also kills bacteria• Become very active during

puberty (but of course you already knew that )

STOP

• “Biore strips”

THE SCIENCE OF ACNE

• Whiteheads• Sebaceous gland’s duct

becomes blocked by sebum

• Blackheads• The sebum that blocks

the gland oxidizes and dries

SWEAT GLANDS• AKA “sudoriferous” glands• Come in 2 types• Eccrine glands• Found all over the body• Produce sweat

• Water, salt, vitamin C, metabolic waste (UREA!!), lactic acid

• Function:• Maintain body temp• Kill bacteria (sweat is slightly acidic)

• Apocrine glands• Axillary and genital regions

• (where are those places in plain English?)

• Secretions are a bit different• It is what makes you have stinky body odor

QUESTION

Sudoriferous glands produce:a) Sebumb) Sweatc) Waterd) Whodee-whattin?

QUESTION

Sebaceous glands produce:a) Sebumb) Sweatc) Waterd) Whodee-whattin?

CREATE A WEB

• Create a web in your notes detailing the differences between sweat and sebaceous glands

HAIR

• Produced by a hair follicle in the dermis• Made of keratinized dead material• Root and shaft

• Your hair’s texture depends on the shape of the shaft (the actual hair itself)

HAIR TYPES

• Oval shaft• Wavy hair

• Flat shaft• Curly hair

• Round shaft• Straight, coarse hair

• Physics: Different hair types will refract light differently

GOOSEBUMPS, ANYONE?

• Attached to the hair follicle in the dermal tissue, there is a tiny muscle• Arrector pili

• Nerves connect to it to stimulate the hair to raise

• Question: what type of muscle tissue is it? • Smooth! You can’t

control your goosebumps!

QUESTION:

• What are the purpose of “goosebumps”? Why was it evolutionarily important that we have this little muscle?• Talk it over with your partner!

UNDA THE DERMIS

• Under the dermis, we have the subcutaneous tissue• Also called “hypodermis”

• We have adipose tissue (fat) in this area

STOP!• Integumentary system coloring sheet

ANSWER THESE QUESTIONS ON THE BACK OF YOUR COLORING SHEET

(QUESTION AND ANSWER):1. The dermis is made out of what kind of tissue?2. Where does the stratum basale get its nutrients

from? BE SPECIFIC!3. Create a venn diagram detailing the differences

between the two types of sweat glands. 4. State the function of the arrector pili muscle.5. Give 2 ways the body is involved in disease

prevention.

BURNS

• Types• Thermal: contact with flame, heat, or scalding liquids• Chemical: contact with acids, bases, and other chemicals• Radiation: exposure to radiant energy from sunlight, x-

rays, or radiation from cancer treatments• Electrical: electricity or lightning

BURNS

• Problems• Body loses supply of nutrients that seep from burned

areas• Dehydration and nutrient imbalance can lead to

circulatory shock• Not enough fluids in the system

• Susceptible to infection because of open wounds

ACID BURNING IN THE MIDDLE EAST

• http://www.dailymotion.com/video/xx0to6_silent-veil-a-documentary-by-depilex-smileagain_shortfilms

SEVERITY OF BURNS

• 1st degree:• Epidermis is damaged and the area may be red and

swollen• Can heal within a matter of days• sunburn

SEVERITY OF BURNS

• 2nd degree burns• Injury to epidermis and upper region of dermis• Skin is red, painful, and blisters appear• Usually no scarring

• 1st and 2nd degree burns = partial-thickness burns

SEVERITY OF BURNS• 3rd degree burns• Destroy the entire thickness of the skin• Full-thickness burn• burned area appears blanched (white/gray) or blackened• Nerve endings are destroyed so there is no pain• Regeneration is not possible• Skin grafting

BURN TREATMENT

• For minor burns (1st and 2nd degree)• Cool the burn under cool running water• Do NOT use ice

• Cover it with a sterile bandage• Do not use butter or ointments if the skin is broken (can

cause infection)

• Take over-the-counter pain reliever

• For major burns• Do not remove burned clothing• Do not immerse in cold water• Elevate burned body parts• Cover the area with cool, moist, sterile bandage

SKIN GRAFTING

BURNS

• Volume of blood can be estimated by determining how much area of the body is burned

• Rule of 9’s• Body is split up into 11

areas (the torso/abdomen area are usually combined), each accounting for 9% of the total body areas, plus 1% represents genital area

Total: 100%

ADULT VS. CHILD PROPORTIONS

• Children have different body proportions than adults

STOP!

• Calculating percent burn with Jack (Jr./Sr.) and Jill (Jr./Sr.)1) State location of burn (hello, body regions!)2) State severity (partial/full thickness, as well as if it is 1st, 2nd, 3rd degree)3) State if grafting must occur4) Calculate the percent burn

• Get with another person, read them your report and see if you both get the same burn percentage

SKIN CANCER GRAPHIC ORGANIZER• With your group members, develop a graphic organizer

that shows the 3 types of skin cancers featured in your text, as well as integrating the ABCD rule• MUST include:• The relative prevalence (most common, least common)• The cells affected (which layer, if there is a specific cell type)• Cure rate• How it is detected (what gives you the warning signs?)

• ABCD rule (goes with melanoma)

• Therapy (if mentioned)

• You will be presenting this information and drawing this information on the board, explaining your organizer• Again, multiple ways of presenting the information = multiple

opportunities for you to find out what makes sense to you