1. Integumentary System

2. (Hypodermis)

3. Integumentary System Skin Hair Nails
Associated Structures (vessels, nerves, glands)

4. Functions of Skin Protection Sensation Excretion
Vitamin D (steroid) production – needed to absorb calcium
Immunity
Healing Wounds
Body temperature homeostasis
vasoconstriction & vasodilation

5. Integumentary System Skin (cutaneous membrane)
Main layers – superficial to deep
Epidermis
Dermis
Hypodermis
(not always considered
part of skin)
(Hypodermis)

6. Epidermal Dendritic Cell Stratum Corneum Stratum Granulosum
Page 26 Epidermis Diagram
Desmosomes
Keratinocytes
Epidermal Dendritic Cell
Stratum Corneum
Stratum Granulosum
Stratum Spinosum
Stratum Basale
Dermis
Sensory Nerve
Melanin
Melanocyte

7. Dermal Papillae Pore Eccrine Sweat Gland Arrector Pili Muscle
Page 28 Skin Diagram
Hair Shaft
Epidermis
Papillary Layer
Dermis
Reticular Layer
Hypodermis
Sensory Nerve
Lamellar Corpuscle
Hair follicle receptor
Dermal Papillae
Pore
Eccrine Sweat Gland
Arrector Pili Muscle
Sebaceous Gland
Hair follicle
Hair root

8. Pg 26 Epidermis Diagram D. E. F. G. H.

9. Skin Structure

10. Pg 27 “Epidermis Functions”
On top
skin
Epidermis – outer layer
Tissue: Keratinized stratified squamous epithelium
Avascular (no blood vessels in this layer)
Renews itself ~ every 45 days (goes through mitosis)
layered
thin & flat

11. Epidermis – cell types within
B.) Keratinocytes (~90% of the epidermis)
produce keratin – waterproof tough flexible protein
accelerated in areas of friction
Callus – thickened skin
Produce hair and nails

12. Epidermis – cell types within
K.) Melanocytes
Produce melanin- brown, yellow brown, or black pigment
Prevents DNA mutation from the UV radiation

13. A.) Desmosomes
Form a tight junction to help layers stay together

14. 5 Layers of the Epidermis
(superficial to deep)
Pneumonic: Come Lets Get Sun Burned
Stratum Corneum
Stratum Lucidum
Stratum Granulosum
Stratum Spinosum
Stratum Basale

15. D.)Stratum Corneum (top layer)
Outermost (15-30 layers of cells)
Also completely keratinized
Tough, waterproofing protection
Dead cells (attached by desmosomes)
Flat cells

16. D.)Stratum Corneum FUN FACTS
Dead cells stay on top for about 2 weeks before they are shed off
This layer is very dry so most bacteria cannot survive

17. Stratum lucidum (2nd Layer)
ONLY found in thicker epidermis – palms, soles, callus
Completely keratinized (and dead!)
Flattened and closely packed

18. D.)Stratum Granulosum (3-5 layers of cells)
Produce a large amount of Keratin
The cell becomes thinner because their cell membranes are thick because of the tough keratin and substances cannot diffuse in

19. F.)Stratum Spinosum (8-10 layers of cells)
Several layers of many sided cells (looks spiny)
Contains Langerhan’s macrophages
Slightly Mitotic
Cytoplasm shrank b/c of chemicals by the cytoskeleton remained

20. G.)Stratum Basale/Germinativum (deepest layer)
Highly Mitotic (produce new skin layers) (WHY?)
Melanocytes
Merkel cells: detect light touch
Epidermal Ridges: attach the epidermis to the dermis
Form our fingerprints