1. I can explain the characteristics of the layers of skin.
Objective:
I can explain the characteristics of the layers of skin.
Agenda
Notes over Function and layers of skin
Skin Lab
Skin Label/Color

2. The Integumentary System

3. General Info…….. Skin has 2 layers Epidermis - _______
Sweat glands excrete sweat through pores.
urea, salts, and water.
Body’s first line of defense!
_______________________________________.

4. The “Birthday Suit” Combination of 4 main tissues:
___________ – outer layer
Connective – underlies dermis
___________– goose bumps
___________ – sensory receptors

5. Functions of the Skin Protection _____________ Sensations
__________________
Excretion of wastes
_________________
Determines characteristics

6. Connections Circulatory system: ________________: ____________________
sensory receptors for pain, touch, and temperature

7. The Skin FG04_02.JPG Title: Components of the Integumentary System
Notes: Relationships among the major components of the integumentary system (with the exception of nails, shown in Figure 4-15).
Keywords: integumentary system, cutaneous, epidermis, dermis, papillary layer, reticular layer, hair follicles, exocrine glands, nails

8. Epidermis Outer layer of dead skin cells called cuticle .
______________________.
“Ashiness” is caused by this layer of dead skin cells being very rough and raggedy.
DUST you see around is made up of dead skin cells!
Under the cuticle is another layer of living _____________ cells that make up the rest of the epidermis.

9. Epidermis and Dermis Epidermis is ____________ (no blood vessels)
Dermis is highly ________________ (has blood vessels)
Epidermis receives nourishment from dermis
Cells far away from nourishment die

10. Epidermis FG04_03.JPG Title: The Structure of the Epidermis
Notes: A light micrograph through a portion of the epidermis, shows the major stratified layers of epidermal cells.
Keywords: epidermis, structure, layers, stratum corneum, stratum lucidum, stratum granulosum, stratum spinosum, stratum germinativum, dermis

11. Organization of the Epidermis
Figure 5–2

12. Cells of the Epidermis _______________:
contain large amounts of keratin
the most abundant cells in the epidermis

13. Thin Skin
Covers most of the body
___________________

14. Thick Skin Covers the palms of the hands and soles of the feet
____________________

15. Structures of the Epidermis
The 5 strata of keratinocytes in thick skin
Figure 5–3

16. Layers of the Epidermis
From basal lamina to free surface:
stratum germinativum
_______________
stratum granulosum
stratum corneum

17. Stratum Germinativum The “germinative layer”:
has many germinative (stem) cells or basal cells
is attached to basal lamina by hemidesmosomes
________________________________________________________________________

18. Structures of Stratum Germinativum
__________________(e.g., fingerprints)
_______________(tiny mounds):
increase the area of basal lamina
strengthen attachment between epidermis and dermis

19. Ridges and Ducts
Figure 5–4

20. Cells of Stratum Germinativum
Merkel cells:
_____________________
________________(trigger nervous system)
Melanocytes:
______________________
scattered throughout stratum germinativum

21. Stratum Spinosum The “___________”:
produced by division of stratum germinosum
8–10 layers of keratinocytes bound by desmosomes
________________________________(spiny)

22. Cells of Stratum Spinosum
Continue to divide, increasing thickness of epithelium
Contain ______________, active in immune response

23. Stratum Granulosum The “_______________”
Stops dividing, starts producing:
_____________:
a tough, fibrous protein
makes up hair and nails

24. Cells of Stratum Granulosum
Produce protein fibers
______________
Create tightly interlocked layer of keratin surrounded by keratohyalin

25. Stratum Lucidum The “___________”: found only in thick skin
covers stratum granulosum

26. Cells of Stratum Lucida
Flat
________
___________

27. Stratum Corneum The “_____________”: ________________
15 to 30 layers of keratinized cells
water resistant
_________________________

28. Keratinization
The formation of a layer of dead, protective cells filled with keratin
__________________________________________________________________

29. Skin Life Cycle
It takes 15–30 days for a cell to move from stratum germinosum to stratum corneum

30. Dermis Thick layer under the epidermis _______________________________
Oil glands
Sweat glands
Hair follicles
Fat tissue
Nerves
Connective tissue

31. Dermis The dermis has several important characteristics:
is composed of connective tissue containing collagen and elastic fibers
____________________
the outer ______________consists of areolar connective tissue containing thin collagen and elastic fibers, __________________(including capillary loops), corpuscles of touch and free nerve endings

32. Dermis
The deeper _____________________consists of dense irregular connective tissue containing collagen and elastic fibers adipose cells, hair follicles, nerves, sebaceous (oil) glands, and sudoriferous (sweat) glands
Striae or stretch marks can appear if the skin is stretched too much

33. Hypodermis
- called subcutaneous, Sub-Q or superficial fascia
- ____________________________
- ______________________________
- common site for injection

35. Hair (pili)
- ________________________________
- hair root nerve plexus for touch
- normal hair loss in adult hairs/day

36. Hair anatomy:
- composed of dead columns of keratinized cells.
- shaft: ____________________
- root: _____________________