1. Body Membranes and the Skin
Intro to Skin and the Integumentary System

2. 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

3. Question:
What are the 4 types of tissues?

4. 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

5. Epithelial Membrane: Cutaneous
Cutaneous membranes
AKA your skin!
“dry” membrane and exposed to air
Stratified squamous epithelium (epidermis) PLUS dense connective tissue (dermis)
Protection
Table in workbook?

6. Question:
What does “epi” mean?
Below
On top of
Within

7. 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

8. Think-Pair-Share
Give 1 similarity and 1 difference between cutaneous and mucous membranes
WRITE THIS IN YOUR NOTES!

9. 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

10. 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!

11. Think-Pair-Share
Name 1 similarity and 1 difference between mucous and serous membranes
WRITE THIS IN YOUR NOTES!

12. 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

13. Question:
Which of the following contains both connective AND epithelial tissue?
Serous membranes
Synovial membrane
Cutaneous membrane

14. Think-Pair-Share
Give 1 similarity and 1 difference between serous and synovial membranes
WRITE THIS IN YOUR NOTES

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

16. 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

17. 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!

18. 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 limited footwear possibilities

19. Epidermis
Split up into 5 zones known as strata

20. Deep to Superficial Keratinocytes contain keratin Stratum Basale
A protein that makes cells hard so they are resistant to damage and desiccation
Stratum Basale
Cells (keratinocytes) 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
Stratum Granulosum
Stratum Lucidum
Cells flatten, become very keratinized, and die
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

21. Why do we lose cells from the stratum corneum?
These cells are the farthest away from the nutrient source
Keratin limits nutrient entry

23. 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

24. 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

25. Other cells Melanocytes Found in the stratum basale Produce melanin
Causes there to be pigment
Function: protect cells from UV damage
Natural sunscreen!

26. melanocyte

27. Predict
Why do we tan?
Put your prediction in your notes

28. 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

29. Question: Why are different races different colors?
Talk with your partner and write a prediction on the white board

30. 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)

31. 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

32. 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?

33. 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

34. In a nutshell.... You have 2 options:
You will get skin cancer if you are exposed to the sun
You will get rickets from staying out of the sun

35. STOP!
Make a model of the cell
Epidermis Parfait

36. Dermis Your “hide” Strong, stretchy, holds you together
2 major regions
Papillary region
Reticular layer
Ed Gein-serial killer
Made human skin hides (bowls, lampshades)

37. 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?

38. STOP Look at your fingerprints! Use pencil lead. Question:
The papillary layer is ___________ to the stratum basale
Superficial
Deep
Whodee-whattin?

39. Reticular Layer Deepest skin layer Contains: Major protein: collagen
Sits atop a layer of adipose tissue
What is another word for adipose tissue?
Contains:
Blood vessels,
Sweat/oil glands
Deep pressure receptors
Major protein: collagen
Responsible for the toughness of the dermis; holds the cells together
Keeps skin hydrated

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

41. Disease: Dystrophic Epidermolysis Bullosa (DEB)
Caused by a mutation in the gene responsible for making collagen
Skin is extremely fragile

42. Appendages of the Skin
Include cutaneous glands, hair and hair follicles, and nails
Mostly contained within the reticular dermal layer

43. Appendages: Cutaneous Glands
All are exocrine glands
They release their secretions onto the cell surface
formed by the cells in the stratum basale
2 types:
Sebaceous glands
Sweat glands

44. 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  )

45. STOP
“Biore strips”

46. The Science of Acne Whiteheads Blackheads
Sebaceous gland’s duct becomes blocked by sebum
Blackheads
The sebum that blocks the gland oxidizes and dries

47. 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

48. Hair Produced by a hair follicle in stratum basale
Made of keratinized dead material
Root and shaft
Your hair’s texture depends on the shape of the shaft (the actual hair itself)

49. Hair types Oval shaft Flat shaft Round shaft
Wavy hair
Flat shaft
Curly hair
Round shaft
Straight, coarse hair
Physics: Different hair types will refract light differently

50. Goosbumps, anyone?
Attached to the hair follicle in the dermal tissue, there is a tiny muscle
Arrector pili
Question: what type of muscle tissue is it?
Smooth! You can’t control your goosebumps!

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

52. STOP!
Integumentary system coloring sheet

53. Burns
Can be caused by intense heat, electricity, UV radiation (sunburn), or certain chemicals (ie acids)
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

54. Severity of Burns 1st degree:
Epidermis is damaged and the area may be red and swollen
Can heal within a matter of days
sunburn

55. 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

56. 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

57. 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, each accounting for 9% of the total body areas, plus 1% represents genital area
Total: 100%

58. STOP! Calculating percent burn with Jack and Jill
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 occur

59. 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)