1. The Integumentary System AHCP

2. SOME FACTS ABOUT THE SKIN THAT YOU ARE IN… Its Waterproof, Stretchable,Washable, yet Tough! Its automatically repairs small cuts, rips & burns & is guaranteed to last a lifetime It weighs 7% of your body weight!

3. Functions of the Integumentary System 1. Protection: provides 3 types of barriers A. Chemical: acid secretions slows bacterial growth (ring tarnish!) B. Biological: Macrophages = wbc’s patrol skin C. Physical barriers: few things able to enter: SSome Fat-soluble substances PPoisons (poison ivy) Solvents- paint thinner Heavy metals- lead & mercury FYI: Transdermal patches are soaked in oils/solvents to carry drug Across - nicotine, birth control & motion sickness!

4. Functions 2. Temperature Control 3. Makes Vitamin D - sunlight converts cholesterol in dermis to Vit. D3 which is needed for calcium uptake 4. Sensation - touch, pressure, pain & temp 5. Storage - fats 6. Excretion (wastes) & Secretions (milk)

5. What Is The Structure of Skin? 3 Layers: Epidermis – Composed of epithelial tissue (stratified squamous) – avascular Dermis – underlies the epidermis – Tough leathery layer composed of fibrous connective tissue – Good supply of blood Hypodermis (a.k.a subcutaneous layer -not considered skin) – Made of adipose and loose connective tissue – Stores fat, anchors skin, protects against blows

6. Epidermis Dermis Basement membrane

8. What are the different types of cells in the epidermis? 1. Keratinocytes  Make the protein keratin = tough & water resistant  Are formed in lowest levels & push up by production of new cells below  Become dead and scale-like, millions rub off everyday FYI: Everything you see on a person is dead! Outer 20-30 cells thick. Average person sheds 40 pounds of these in a lifetime!

9. What are the different types of cells in the epidermis? 2. Melanocytes melanocyte Melanin in keratinocytes  Absorbs ultraviolet light so skin is not damaged  Make pigment melanin (melan = black)

10. What are the different types of cells in the epidermis? 3. White blood cells Langerhans ’ cell  They Macrophages, which patrol & eat bacteria/viruses

11. What are the different types of cells in the epidermis? 4. Sensory Cells  Connected to nerve cells from dermis  Sense touch.

13. Characteristics of the Dermis Connective tissue has lots of collagen & elastic fibers - gives skin strength Extensibility = able to stretch (elbow skin) Elasticity = able to return to its original shape after extension/contraction (pregnancy & swelling) Thickest = Thinnest = Palms/soles Eyelids

14. More Characteristics… Sense Receptors: touch & pressure receptors Ridges formed from papillary layer form finger prints. http://bio.rutgers.edu/~gb102/lab_5/104bm.html

16. What are the major structures in Dermis? Sweat glands Sebaceous glands Hairs Nails

17. Sweat Glands 1. Common sweat (merocrine)  Watery sweat  Heat & waste loss (all over skin - lots on palms/soles) 2. “Funky” sweat (apocrine)  Milky/yellow thick sweat - thought to be scent glands  Starts at puberty  Armpits & groin 3. Ear wax! (ceruminous) 4. Milk (mammary)

18. Sweat Glands 1. Merocrine (common sweat glands)  Watery sweat  Heat & waste loss (all over skin - lots on palms/soles) 2. Apocrine ( “ funky ” )

19. Sweat glands

20. Sebaceous Glands Sebum = oil - around hair follicles, none on palms/soles  Softens and lubricates hair and skin  Slows water loss and kills bacteria Blackheads - built up sebum Pimples - Built up sebum is a nutrient for bacteria (puss!)

21. Sebaceous Glands

22. Hair Made of dead keratinized skin cells 2 parts = shaft & root Function = Protection! FYI on Hair:  You have about 100,000 hairs on your head  You lose about 100/day  It grows ~0.5 in/month - goes through cycles  Hirsutism = excessive hair growth (often in women due to disease)

23. Hair  You have about 100,000 hairs on your head  You lose about 100/day  It grows ~0.5 in/month - goes through cycles  Hirsutism = excessive hair growth (often in women due to disease)

24. Hair Follicles

26. NAILS A scale-like modification of the epidermis Made of tightly compressed keratinized cells Useful tools to pick up small objects or scratch an itch. Nail matrix is the region responsible for nail growth. FYI: Nails & Hair DON ’ T grow after death - skin just shrinks!

28. What causes the color of skin? 1. Melanin Range in color from yellow to reddish-brown to black Everyone has the same # of melanocytes but make varying amounts & colors Sunlight increases production! Clusters create moles & freckles 2. Carotene-yellow to orange pigment found in foods. Most in the palms or soles. 3. Hemoglobin- Red blood (from dermal layer)gives a pinkish hue to fair skin 3 pigments contribute to skin color

29. Aging Skin (A billion dollar industry!) Major Age-Related Changes – Injury and infection increase – Immune cells decrease – Sun protection diminishes – Skin becomes dry, scaly – Hair thins, grays – Sagging, wrinkles occur – Heat loss decreases – Repair slows = loses melanin & fills with air!

30. Skin Injury & Repair

32. Skin Cancer Benign lesions such as warts and moles are not serious. Malignant tumors can start on the skin and invade other body areas. Crucial risk factor- overexposure to UV radiation

33. Types of Skin Cancer Basal cell carcinoma- most common, 30% of all white skin people get it. – 99% curable if caught early – Dome shaped nodules that form an ulcer in the center. Squamous Cell carcinoma- – Grows rapidly and metastasizes if not removed – Small red rounded elevation on the skin

34. Basal Cell Carcinoma

35. Squamous cell carcinoma

36. Lesion removed from patient Basal Cell Carcinoma

37. Skin Cancer Types cont. Melanoma – Cancer of melanocytes (very dangerous) – 5% of skin cancers but rising fast – Can arise from preexisting moles – Appears as a spreading brown or black patch – Chance of survival is poor if the lesion is greater than 4 mm thick

38. Melanoma

39. What is the ABCD rule? Used for recognizing melanoma

40. Third-degree burn Second-degree burns