Integumentary System

1. Integumentary System HSI

2. Epidermis Outermost covering Epithelial cells Avascular Dermis True skin Connective tissue Vascular Day 1- STRUCTURES AND FUNCTIONS OF THE SKIN2 basic layers

3. STRATUM CORNEUM Outermost layer In cells, cytoplasm replaced by KERATIN – making them waterproof. Flat and scale-like cells that flake off First line of defense against surface bacteria Thickest on palms of hands, soles of feet STRATUM GERMINATIVUM Innermost epidermal layer Reproductive layer – cells form and push their way up, become keratinized, and replace the top layer Contains MELANOCYTES – cells that contain a pigment = MELANIN EPIDERMIS

4. Melanin  Black, brown, or has a yellow tint – • depending on racial origin  The more melanin, the darker the skin  Caucasians don’t have much melanin in their melanocytes.  Freckles = patches of melanin Albinism = no melanin

5. PAPILLAE • Ridges in stratum germinativum that arise from dermis • Create permanent ridges in fingers, palms and soles of feet • These “friction ridges” help with grip • Cause “fingerprints”

6. 7 Functions • Protection • Absorption • Regulation • Sensation • Vitamin D production • Excretion • Storage/ Insulation

7. Epidermis- Protection • Protective shell- protects from invaders- bacteria, viruses, etc. Our first line of defense. • Melanin filters UV rays • The cells of the epidermis are constantly renewing themselves, with dead skin cells falling off by the tens of thousands each minute.

8. Epidermis • Stratum Corneum- Dead shedding skin layer • Stratum Germinativum- manufactures new skin cells

9. Thicker inner layer that contains: Connective tissue Blood vessels Nerve endings Muscles Hair follicles Oil and sweat glands Fat cells- Adipose tissue DERMIS

10. Dermis- Absorption • Skin absorption is a route by which substances can enter the body through the skin. • Certain drugs can be absorbed through the skin, dermal route- Nitroglycerine, scopolomine, fentanyl, ointments.

11. Dermis- Regulation • The dermis controls body temperature through the production of sweat and the control of evaporation  • When the body is cold, the red blood cells of the dermis contract, which helps to retain internal body temperature. When the body is hot, the red blood cells expand, allowing heat to be released through the surface of the skin

12. Dermis- Sensation • The nerve endings in the dermis identify five different kinds of sensations: heat, cold, pressure, pain and contact • Nerve Receptors in Dermis • Touch receptors close to the surface • Pressure receptors are deeper

13. Dermis- Production of Vitamin D •  Having enough vitamin D is important for your health because without it your body wouldn't be able to keep up proper levels of calcium and phosphorus. That means you need vitamin D if you want to have healthy, strong bones and teeth. • To make vitamin D, your skin needs adequate exposure to the sun. Your skin contains a cholesterol substance called provitamin D3 that reacts with the ultraviolet-B (or UVB) rays in sunlight to form vitamin D3. From there, the body takes over, first passing the vitamin D through the liver and then through the kidneys, converting it along the way into the form that the body needs • 10 minutes of fun in the sun is enough to let your skin do its vitamin D magic.

14. Dermis- Excretion Sebacous Glands-Secret oil (SEBUM) that protects waterproofs and lubricates the skin. • Connected to hair follicles. Bacteria on the skin eats the oil. Sudoriferous Glands- Secretes sweat- When mixed with bacteria on the skin it creates an odor.

15. Lies under the dermis (not really part of integumentary system) Made up of loose connective tissue Contains half of the body’s stored fat Subcutaneous- Hypodermis

16. Subcutaneous- HypodermisStorage/ Insulation • Stores 50% of the body fat • it provides insulation against the absorption of cold and the loss of heat • Is highly vascular- Best route to for some drugs- insulin- stored in fat and slowly released.

17. Appendages of the Skin • HAIR • Almost everywhere on the body • Length, thickness, type and color varies • Outer layer = CORTEX • Inner layer = MEDULLA • Part under the skin = ROOT • Part outside the skin = SHAFT • FOLLICLE = pocket in epidermis, hair inside • PAPILLA = tuft of tissue in root, contains capillaries

18. Appendages of the Skin • ARRECTOR PILI MUSCLE = smooth muscle attached to hair follicle. How does this muscle cause goose bumps? • NAILS • Nail is formed in the nail bed or MATRIX • Epidermal cells fused together and fill with keratin

19. Hair • An arrector pili muscle is associated with the hair shaft and contracts with cold, fear and emotion to pull the hair erect, giving the skin `goose bumps'. • Protection from the suns rays.

20. Nails • To protect the tip of the fingers and to aid grasping. • Pale- anemia, malnutrition • White- liver disease • Yellow- fungal infection • Blue- decreased oxygen • Rippled- arthritis • Cracked or split- thyroid disease, fungus • Puffy nail fold- lypus • Dark- melanoma • Gnawed- anxious

21. Sudoriferous Glands(Sweat Glands) • Perspiration is 99% water • Distributed over the entire skin surface • Large numbers under the arms, palms of hands, soles of feet and forehead • Duct extends to form a pore in the skin, perspiration excreted through the pores • May be activated by heat, pain, fever and nervousness • Average fluid loss is 500 ml per day

22. Sebaceous glands • microscopic glands • located adjacent to a hair follicle (shaft) Secrete an oily or waxy matter, called sebum, to lubricate and waterproof the skin

24. Processing Guess the Fib, Labeling Activities 1,2 and 3, Processing Structures Disorders of the Integumentary System WS- look up in textbook

25. Day 2- Disorders Integumentary System Disorders- look up in textbook. Page numbers are on WS.

26. Warm up • What layer of the skin is the hair follicle located? • What structures are an appendages to the skin? • What is the outer layer of the hair called? • What structures are located in the dermis? • What is another name for the matrix of the nail? • What is the inner most layer of the skin? • What layer of the skin contains 50% of the bodies fat (adipose)? • Where are the greatest number of sudoriferous glands located? • What is the substance that the nails are made of? • What gives the skin it’s color? • What layer of the skin would undergo the greatest change if a person gains weight?

27. The best way to prevent the spread of disease is by hand washing Intact skin = best protection against pathogens, toxins and water loss Skin generally too dry for microbial growth – they do grow in moist areas Most skin bacteria associated with hair follicles or sweat glands Underarm perspiration odor caused by bacteria and perspiration Skin and Microorganisms

28. Proteins in blood, such as fibrin, work with the blood platelets already in place and plasma to form a protective covering called a scab. While your skin regenerates underneath the protective layer, the scab protects the wound from outside infection. The wound is gradually healed as new granular skin tissue begins to generate. Starting at the edges of the wound, the new tissue forms and works its way toward the center until it has covered the entirety of the lesion. Once the wound underneath has sealed itself with another skin layer, the scab will slough off on its own. If it is only in the epidermis, it will not scar. If it is in the dermis and below it will cause a scar. Healing