1. Structure of the Skin
Tackmann
A & P

2. Layers of the Skin
Epidermis
Dermis
Subcutaneous Tissue

3. Epidermis Keratinized – has become hard and tough 5 Zones
Stratum Corneum – 20 to 30 cells deep (dead cells filled with keratin)
Stratum Lucidum – only on palms and soles of feet
Stratum Granulosum
Stratum Spinosum
Stratum Basale
Mitosis!!!!!!
Nourishment rich

4. Epidermis Elevator System
Cells move upward replacing the layer above them
Totally new epidermis “skin” every days!!!

5. Stratum Corneum
Stratum Lucidum
Stratum Granulosum
Stratum Spinosum
Stratum Basale

6. Melanin and Melanocytes
Pigment that ranges from yellow to black
Produced by “Melanocytes”
Found in stratum basale layer

7. Melanin and Melanocytes
Sunlight stimulates melanocytes
Stratum basale cells phagocytize (eat) the secreted melanin
Melanin then protects the cell from sunlight
Shields the DNA
Too much UV will damage the DNA – Causes skin cancer
Freckles and Moles
Concentrated melanin

9. Dermis
Two Regions
Papillary Layer
Reticular Layer

10. Papillary Layer Upper region of the dermis Dermal Papillae
Upward projections that indent into the epidermis

11. Dermal Papillae
Contain capillary loops to supply nutrition to the stratum basale
Contain Meissner Corpuscles
Sensory nerve endings
Sense pain

12. Dermal Papillae Looping patterns of papillae on feet and hands
Increases gripping ability in these regions
Genetically determined
Results in your personal unique fingerprint

13. Reticular Layer Deepest skin layer Contains Blood vessels Sweat glands
Oil Glands
Pacinian Corpuscles
Sensory neurons that sense pressure

14. Reticular Layer Abundant with phagocytes
Special cells eliminate bacteria that sneak through the epidermis

15. General Characteristics of the Dermis
Rich with Collagen and Elastic Fibers
Collagen = toughens and hydrates the skin
Elastic = provides skin with elasticity

16. Appendages
Glands
Sebaceous and Sweat
Hair
Nails

17. Cutaneous Glands Two Groups Sebaceous Glands Sweat Glands
Eccrine Glands
Apocrine Glands

18. Sebaceous Glands Location Ducts empty into hair follicle All over body
NOT on palms and soles of feet
Ducts empty into hair follicle
Sometimes directly onto the skin too

19. Sebaceous Glands Create Sebum
Natural lubricant made of oil and fragmented cells
Keeps skin soft/moist
Prevents brittle hair
Chemicals that kill bacteria
VERY active during puberty

20. Blocked Sebaceous Gland
If gland gets blocked by Sebum
Whitehead Forms
If it oxidizes and dries it darkens and forms a Blackhead

21. Sweat Glands
Two Types:
Eccrine Glands
Apocrine Glands

22. Eccrine Sweat Glands Location: Produce Sweat Acidic (4 – 6 pH)
Entire body
Produce Sweat
Made of…
Water
NaCl
Vit. C
Ammonia, Urea, Uric Acid
Acidic (4 – 6 pH)
Prevents bacteria growth

23. Apocrine Sweat Glands Location: Empty into hair follicles Made of…
Axillary/Genital regions
Empty into hair follicles
Made of…
Eccrine Sweat sections plus…
Fatty Acids & Proteins
Milky/Yellowish color
Bacteria grow here!!!

24. Hair and Hair Follicles
Protective Functions
Head – bumps
Eyelashes – protect eyes
Nose hairs – filter
Many more…..

25. Hair Anatomy Root Shaft Hair Bulb Matrix
Part of the hair enclosed in the follicle
Shaft
Part of the hair projecting from the skin
Hair Bulb Matrix
Division of stratum basal cells in the “growth zone”
As cells move up and away they die and karatinize

26. Hair Shaft Shape Oval Shape Flat and Ribbon like Round
Smooth, silky, Long and Wavy hair
Flat and Ribbon like
Curly or Kinky hair
Round
Straight and coarse

27. Hair Color Melanocytes found in the hair bulb
Various shades of melanin secreted

28. Hair Follicles (page 100) Inner epidermal sheath Outer Dermal sheath
Forms the hair
Outer Dermal sheath
Supplies blood vessels to the epidermal layer
Supports the epidermal layer

29. Arrector Pili Connects hair follicle to dermal tissue
Contracts and pulls hair to stand on end
Cold Temps or Frightening situations

30. Nails Purpose??? Protects distal phalanges Tool for cutting/scraping
Enhances sensitivity with touch and movement with the tips of our fingers/toes

31. Nails Made of Keratin Nail Matrix Growth zone Makes the nail plate
Same as horns and hooves
Nail Matrix
Growth zone
Makes the nail plate
Rate of 3mm a month

32. Nail Bed Two Layers Epidermis moves with the nail plate Epidermis