1. INTEGUMENTARY SYSTEM
C L G S B

2. Your skin, also called the cutaneous membrane, is an epithelial membrane that covers the entire body.

3. FUNCTIONS: Integumentary System Includes:
Protects against injury and infection
Removes waste products
Regulates body temperature
Sense of touch
Collagen ridges give us our fingerprints
Integumentary System Includes:
skin, glands, hair, and nails

4. 3 LAYERS OF THE SKIN EPIDERMIS  (stratified squamous)
DERMIS  (dense connective tissue)
SUBCUTANEOUS TISSUE **(HYPODERMIS)  adipose tissue
(subcutaneous layer often not considered part of skin)

5. HUM SKIN!

6. EPIDERMIS “your epidermis is showing” Avascular 5 layers (strata)
Stratified squamous cells
Keratinocytes produce keratin (TOUGH, fibrous protein; functions are protection and durability)

7. LAYERS OF THE EPIDERMIS
FROM SUPERFICIAL TO DEEP:
Stratum corneum
Stratum lucidum
Stratum granulosum
Stratum spinosum
Stratum basale

10. STRATUM CORNEUM “horny layer” Outermost epidermal layer
Made up of 20 to 30 cell layers
Keratinization = cells gain keratin and are constantly sloughed off and replaced by new cells

11. STRATUM LUCIDUM Thin layer, but makes skin here thicker Clear, dead
keratinocytes
*Only found where skin is hairless
(palms and soles of feet)

12. STRATUM GRANULOSUM Many granules in cells
Some granules contain a waterproof lipid and others contain keratin
Upper portions are beginning to die here

13. STRATUM SPINOSUM “spiny layer” Cells appear spiky
Some cell division occurs in this layer
Receives some nourishment from the dermis (by diffusion of blood)

14. STRATUM BASALE One row of cells right above dermis
Cells constantly reproducing through cell division
Adequate blood supply from dermis
Melanocytes (pigment cells)
produce the pigment (MELANIN) in this layer

15. How does the skin do it?? *Cells in the lower strata of the epidermis
(mostly in stratum basale and some in stratum spinosum)
are constantly undergoing cell division
(millions of new cells made daily)
and the new cells are pushed upward,
away from the blood supply of the dermis
to become part of the layers that are closer to
the skin’s surface.
As the cells move upward toward stratum corneum
they start to die off and become flatter.
These cells have more protective keratin in them.