1. Integumentary System – Skin Layers Updated by S. Mendoza 8/2013
Essentials of Human Anatomy & Physiology
Seventh Edition
Elaine N. Marieb
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

2. Skin Structure page 101 (This is on pg 4 of notes – You need know all of your diagrams!
Figure 4.4
Slide 4.13b
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

3. Begin pgs 5-6 of notes
Look at diagrams carefully to see which layer the information is referring to. Remember: Structure determines Function!

4. Epidermis – page 6 of notes - fill in text box on left side of diagram
Epidermis – outer layer – color code brackets
Keratinized stratified squamous epithelium
Avascular (hardened by keratin)
Renews itself ~ every days
Need to know this slide!
Slide 4.10a
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

5. Dust Mites – eat your dead keratinocytes

6. Epidermis – cell types – Go to page 5 of notes & fill in cell info (upper right)
Keratinocytes
produce keratin – waterproofing protein
Why important? To keep you from gaining/losing water
Originate in deeper layers & get pushed to surface – becomes keratin filled & dies
Reminder: Connected to each other by desmosomes & tight junctions
Cell production & keratinization are accelerated in areas of friction
Callus – thickened skin for protection
Slide 4.10a
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

7. Keratinocyte Growth

8. Epidermis – cell types – pg 5
Melanocytes
Produce melanin which accumulates on superficial (between nucleus & sun) side of nucleus
Why that location? to prevent DNA mutation from the UV radiation
Mutation can change growth instructions & cause cancer
Slide 4.10a
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

9. Melanocytes

10. Label the 5 strata on page 5 left side

11. From deep to superficial Stratum basale highly mitotic
5 epidermal strata– place info on page 5 right side
From deep to superficial
Stratum basale
highly mitotic
Approx. 25% melanocytes
Stratum spinosum
Slightly mitotic
Contains Langerhan’s macrophages
Slide 4.10a

12. 5 strata of the Epidermis
Stratum granulosum
Also contains Langerhans cell
contains keratin granules
Stratum lucidum
found in thicker epidermis – palms, soles, callus
Completely keratinized (and dead!)
Slide 4.10a
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

13. 5 strata of the Epidermis
Stratum corneum
Also completely keratinized (& dead)
Tough, waterproofing protection
AGAIN: Why is waterproofing important?
Slide 4.10a
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

14. How it all fits together

15. Dermis – back to page 6 Left side: Strong, flexible CT - 2 layers
Right side - Papillary dermis
Contains areolar CT
Dermal papillae – indent into the epidermis – form fingerprints
What else is important about these? Give us grip !
Also contain
nerve receptors,
capillary loops etc.
Slide 4.13a
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

16. Blister: add in margin pg 6
Dermal – epidermal junction
Held together by desmosomes
Blister - separation due to mechanical stress
What 2 sublayers actually separate? Think about this!!

17. Dermis Page 6 right side Reticular Dermis
Reticular CT & Dense irregular CT – also contains Blood vessels, Nerve receptors, Glands
cleavage lines – direction of fibers in collagen bundles – used in plastic surgery to reduce scarring
flexure lines – dermis secured to hypodermis
stretch marks – dermal tears
Slide 4.13a
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

18. Cleavage lines

19. Dermis

20. Hypodermis – pg 6 left side
Deep to dermis is the hypodermis - superficial fascia
Anchors skin to underlying organs, shock absorption, insulation
Composed mostly of adipose tissue
Very vascular
Site of subcutaneous injections
Slide 4.10b
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

21. 5 Tissues
There have been 5 types of tissues during the previous slides
Find the 5 types & write them in the margin on page 6: You will need to MEMORIZE the location/function/slide of these 5 for this unit test