1. The Integumentary System

2. Major roles of the Integumentary System
protection
maintenance of normal body temperature
storage (of fat)
synthesis (of vitamin D)
excretion (of salts, water and wastes in sweat)
sensory perception

3. The Skin: 3 Major layers

4. Did You Know?...
At 8-10 pounds, the skin is bodies largest organ!

5. The Epidermis
The epidermis is the outer layer of skin. The thickness of the epidermis varies in different types of skin. It is the thinnest on the ______ at .05 mm and the thickest on ______ at 1.5 mm.
Cells of the epidermis are constantly sloughing off and replacing themselves…

6. The Epidermis cont… 5 layers
Cells are shaped like columns at the base and migrate upward, as dead cells are continuously sloughed off at the surface
stratum corneum
stratum licidum
stratum granulosum
stratum spinosum
stratum basale

7. Which layer of the epidermis is this?

8. Specialized Epidermal Cells
The melanocyte- produces pigment (melanin)
The Langerhans' cell- frontline defense of the immune system in the skin

9. They aid in grasping objects, scratching, and protecting fingers and toes.

10. The Dermis
This layer varies in thickness as well, depending on the area of the body. It is a mere 0.3 mm on the eyelid and 3.0 mm on your back.
The dermis is composed of 3 types of tissue….

11. The Dermis cont…
2 types of tissue that are present throughout (not in layers).
collagen
elastic tissue

12. Dermis Tissue: Collagen
Collagen is the most abundant and important structural protein in your body. It strengthens and supports many body tissues from the outside creating an “extracellular matrix.”

13. Dermis: Elastic tissue
Elastic protein fibers made by cells called fibroblasts provide protection for tissues underneath the dermis as well as the pliability we associate with the skin.

14. Specialized Dermal Cells
erector pili muscle cells support hair follicles.
oil (sebaceous) glands, scent glands, and sweat glands are associated with the follicle.
Blood vessels and nerves course through this layer. The nerves transmit sensations of pain, pressure itch, and temperature, and blood vessels facilitate gas exchange.

15. The Importance of Glands
Sweat glands play an important role in keeping the body cool
sebaceous glands secrete sebum which has waterproof and antimicrobial properties

17. What makes these hairs stand on end? Why?

18. Can you name structures 1-4?

19. Layer 3: The Subcutaneous
Also referred to as the “hypodermis,” this layer of the skin is composed primarily of adipose tissue (fat). This layer plays a key role in insulating the body and regulating the temperature of the skin.
The hypodermis can vary significantly in thickness and incorporates larger blood vessels and nerves.

21. Nails
Your nails extend from the epidermis and contain a tough protein called keratin. They play an important role in grasping objects, scratching, and protecting fingers and toes.

23. Did you Know?
Your fingernails grow about 5 times faster than your toenails!

24. Hair
Also composed of the protein keratin hair acts as an effective insulator between you and the environment.
hair follicles originate in the dermis.

25. Did You Know?
Hair can grow as little as 0.1 inches per month or as fast as 0.5 inches per month depending on genetics and your diet.

26. Aging and the integumentary system
Marked declines in:
Cell division in stratum basale
Melanocyte production
Glandular activity
Hair follicle function
Elastic fiber function in dermis
Blood supply to skin
Rate of repair

27. Disorders of the skin Lesions and tumors
infections (bacterial, viral, fungal, parasitic)
inflammatory reactions and allergies
Genetic diseases
acne

28. Anatomy of a Pimple