INTEGUMENTARY SYSTEM

1. INTEGUMENTARYSYSTEM

2. INTEGUMENTARY Presentations • Minimum of 7 slides • Will replace test • All lab members must present to receive full credit • Provide medicinal and layman terminology regarding the topic. • LOTS of pics please…make them good • One statistical bit of information regarding the topic. • Members will grade each other and class will grade group!

4. The Skin (Basic Characteristics) • Waterproof • Stretchable • Washable • Permanent-press • Invisibly repairs small cuts, rips, and burns • Guaranteed to last a lifetime with reasonable care • Weighs on average between 9 and 11 pounds (approx. 7%-15% of total body weight) • Measures between 1.5 and 4 mm thick • Thick skin –Does not have hair follicles or oil glands

5. One last interesting FACTOID about skin: • Every square centimeter of skin contains… • 70 cm of blood vessels, • 55 cm of nerves, • 100 sweat glands, • 15 oil glands, • 230 sensory receptors, and • approximately 500,000 cells that are constantly dying and being replaced (you lose 40 lbs of cells within your lifetime) • Function: • Protection • Structure: • Composed of two major regions: epidermis and dermis

6. Epidermis No Labeling YET!!! • Composed of epithelial cells • Not vascular • Made up of 4 types of cells • Consists of 4-5 distinct layers • New epidermis is regenerated every 25-45 days

7. Cells of the Epidermis

8. Epidermal Cells AKA: The Dendritic Cell

9. 4 Types of Cells: • Tactile Cell • AKA Merkel cell) functions as a sensory receptor for touch • Langerhans’ cells • Macrophages that help to activate immune system • Keratinocytes • Produce keratin, waxy coating • Melanocytes • Synthesize pigment called melanin • Protect cell from UV radiation

10. Layers of Epidermis • In thick skin (soles of feet and palms of hands) there are five layers (strata); everywhere else has four • Deep to Superficial: • Stratum basale • Stratum spinosum • Stratum granulosum • Stratum lucidum (only present in thick skin) • Stratum corneum

11. Dermis • Strong, flexible connective tissue • Cell types: • Fibroblasts • Macrophages • Mast cells • White blood cells • Binds the entire body together • Your HIDE • Vascularized • Hair follicles, oil glands, and sweat glands • 2 major layers: • Papillary layer • Reticular layer

12. Papillary Layer • Highly vascularized • Borders the stratum basale of epidermis • Touch and pain receptors • On palms and soles, these papillae lie atop dermal ridges, which produce whorled epidermal ridges (fingerprints)

13. Reticular Layer • 80% of dermis layer • Collagen binds water, helping to hydrate the skin • Elastin fibers give skin elasticity

14. The Hypodermis • Known as subcutaneous tissue or superficial fascia • Structure: • Has more adipose than dermis • Functions: • Energy reservoir • Thermal insulation • Hypodermic injections • Into subcutaneous tissue since highly vascular Hypodermis

15. Subcutaneous Fat Distribution

16. PIGMENTS of the SKIN • Melanin = brown • Carotene = orange • Hemoglobin = red

17. Carotene • Yellow to orange pigment found in certain plant products • Accumulates in stratum corneum and in adipose tissue of hypodermis • Most obvious in palms and soles where S. corneum is thickest

18. Hemoglobin • Red pigment of red blood cells (RBCs) • Since Caucasian people contain relatively small amounts of melanin, their skin is nearly transparent which allows hemoglobin’s color to shine through

19. Sweat Glands • Exist all over skin except nipples and part of external genitalia (more than 2.5 million/person) • 2 types: • Eccrineand apocrine

20. Eccrine Sweat Glands • Much more numerous • Most abundant on palms, soles, and forehead

21. Eccrine Sweat Glands • Secretion-called sweat-is 99% water, with some salts, vitamin C, antibodies, traces of urea, uric acid, ammonia • Also contains lactic acid, which is the chemical that attracts mosquitoes • Normally of pH 4 to 6

22. Apocrine Sweat Glands • Most common in armpit and anogenital regions • Larger than eccrine glands • Ducts empty into hair follicles • Apocrine secretion has generally same composition as normal sweat, however it has fatty acids and proteins which makes it more viscous • Odorless, however, when decomposed by bacteria on skin a “Body Odor” is created

23. Ceruminous Glands • Modified apocrine glands found in the lining of external ear canal • Secrete sticky cerumen (earwax) • Thought to deter insects (bitter flavor) and block entry of foreign particles

24. Mammary Glands • Specialized apocrine sweat gland that secretes milk • Exist in both men and women • Males – little mammary tissue • Females – milk develops with increase of hormones when pregnant and after birth • Prolactin • Progesterone • Estrogen

25. Nails • Modification of epidermis • Corresponds to hoofs or claws of other animals • Contains hard keratin (like hairs) • Clear, hard derivative of stratum corneum • Growth rate is 1 mm/week • New cells added by mitosis in the nail matrix • Growth zone at proximal edge of nail • Structure: • Nail bed is skin on which nail plate rests • Hyponychium is epithelium of nail bed

26. THE END TIME FOR THE PRESENTATIONS