1. THE INTEGUMENTRY SYSTEM ANATOMY & PHYSIOLOGY CHAPTER 5

2. INTRODUCTION TO STRUCTURES OF THE INTEGUMENT AND THEIR FUNCTIONS SKIN = ORGAN SYSTEM, LARGEST, MOST ACCESSIBLE, VERY UNDERAPPRECIATED INTEGUMENTARY SYSTEM AKA THE INTEGUMENT 16% OF TOTAL BODY WEIGHT (OR ABOUT 2 LBS) 1.5 – 2 M 2 DEFENSE FROM ABRASION, UV RADIATION, ENVIRONMENTAL CHEMICALS, MICROBES 1 ST LINE OF DEFENSE 2 MAJOR PARTS: CUTANEOUS MEMBRANE AND ACCESSORY STRUCTURES

3. CUTANEOUS MEMBRANE EPIDERMIS SUPERFICIAL EPITHEILIUM (TISSUE) AVASCULAR – SHORT DISTANCE FROM DERMIS FOR DIFFUSION KERATINOCYTES; THIN SKIN, 4 LAYERS, 0.08MM 4 LAYERS ARE STRATUM CORNEUM, STRATUM LUCIDUM, STRATUM GRANULOSUM AND STRATUM SPINOSUM PALMS AND SOLES HAVE THICK SKIN, 0.5MM DERMIS UNDERLYING CONNECTIVE TISSUES LOTS OF BLOOD VESSELS SENSORY RECEPTORS HYPODERMIS (LOOSE CONNECTIVE TISSUE TO OTHER STRUCTURES LIKE MUSCLES) ACCESSORY STRUCTURES HAIR NAILS EXOCRINE GLANDS

4. FUNCTIONS PROTECTION AGAINST IMPACT, ABRASION, CHEMICALS, FLUID LOSS (HYDRATION !) EXCRETION SALTS, WATER AND ORGANIC WASTES MAINTENANCE OF TEMPERATURE EVAPORATIVE COOLING PRODUCTION OF MELANIN REQUIRES UV LIGHT PRODUCTION OF KERATIN WATER REPELLANT SYNTHESIS OF VITAMIN D HORMONES RELATED TO CALCIUM USE STORAGE OF LIPIDS ADIPOCYTES SENSATION TOUCH, PAIN, PRESSURE AND TEMPERATURE SENSORS OF NERVOUS SYSEM

5. FIGURE 5-1 THE COMPONENTS OF THE INTEGUMENTARY SYSTEM Cutaneous Membrane Accessory Structures Epidermis Dermis Papillary layer Reticular layer Hypodermis Hair shaft Pore of sweat gland duct Tactile corpuscle Sebaceous gland Arrector pili muscle Sweat gland duct Hair follicle Lamellated corpuscle Nerve fibers Sweat gland Artery Vein Fat Cutaneous plexus

6. PIGMENTATION CAROTENE ORANGE YELLOW PIGMENT FOUND IN DERMIS FOUND IN FRUITS AND VEGETABLES CONVERTED TO VITAMIN A – NEEDED FOR SKIN AND PHOTORECEPTOR PIGMENTS MELANIN BROWN, YELLOW BROWN OR BLACK IN STRATUM BASALE AND STRATUM SPINOSUM, MAY LAST UNTIL STRATUM GRANULOSUM RATIO OF MELANOCYTES TO BASAL CELLS CAN RANGE FROM 1:4 – 1:20 FRECKLES AND DARKER COMPLEXIONS MAKING MORE MELANIN, NOT MORE CELLS USEFUL IN REFLECTION UV RADIATION, MORE MELANIN PRODUCED IN RESPONSE TO UV EXPOSURE, LAST ABOUT 10 DAYS

7. DERMAL CIRCULATION LOTS OF BLOOD VESSELS IN SKIN REGULATION OF TEMPERATURE, AND DELIVERY OF OXYGEN AND NUTRIENTS REMOVAL OF TOXINS REDDER SKIN WHEN VESSELS ARE DILATED, ALMOST WHITE (OR BLUE) WHEN CONSTRICTED – MOST OBVIOUS IN THINNEST SKIN LIKE LIPS AND NAILS JAUNDICE – LIVER FUNCTION, BILE NOT EXCRETED, YELLOWISH TONE TO SKIN PITUITARY TUMORS – EXCESS MELANIN PRODUCTION ADDISON’S DISEASE – ALSO RELATED TO PITUITARY FUNCTION AND MELANIN VITILIGO- LOSS OF MELANOCYTES AND SUDDEN/ COMPLETE LOSS OF PIGMENT

8. VITAMIN D TOO MUCH SUN IS BAD BUT ….. UV RADIATION NEEDED TO MAKE MELANIN – RELATION TO OTHER PIGMENTS UV RADIATION ALSO NEEDED TO CONVERT CHOLECALCIFEROL INTO VITAMIN D3; USED WITH CALCITRIOL TO CONTROL CALCIUM CONCENTRATIONS AT KIDNEY LEVEL AND IN SMALL INTESTINE CALCIUM IS ABSORBED IN SMALL INTESTINE CALCIUM NEEDED FOR BONE GROWTH AND STRUCTURE, INCLUDING TEETH CALCIUM ALSO PART OF MUSCLE CONTRACTION PROCESS

9. SKIN CANCER MOLES AND WARTS ARE BENIGN TUMORS AND VIRUSES SKIN CANCER MOST COMMON FORM OF CANCER VERY DANGEROUS MELANOMA DETECTION AASYMMETRY B BORDER CCOLOR DDIAMETER (5 MM OR 0.02 IN)

10. THE DERMIS BETWEEN EPIDERMIS AND HYPODERMIS EPI = ABOVE HYPO = BELOW 2 MAJOR COMPONENTS PAPILLARY LAYER PROJECTIONS (PAPILLI) INTO EPIDERMIS LAYER CONTAINS BLOOD VESSELS, LYMPH VESSELS NERVE ENDINGS MADE OF AREOLAR TISSUE (CT) RETICULAR LAYER MESH OR NETWORK OF RETICULAR TISSUE (CT) HOLDS DERMIS TO HYPODERMIS LOTS OF COLLAGEN AND ELASTIC FIBERS DERMATITIS IRRITATIONS AND INFECTIONS OF THIS LAYER ARE REALLY PAINFUL (POISON IVY)

11. HAIR 2.5 MILLION HAIRS ( ONLY 500,000 ON HEAD) 75% ON SURFACE OF BODY AND NOT ON HEAD VELLUS HAIRS ON BODY TERMINAL HAIRS ON HEAD PRODUCED BY HAIR FOLLICLES GROW FOR 2-5 YEARS AND ARE SHED ACTUALLY HAVE MANY ROLES PROTECT FROM UV RADIATION CUSHION INSULATE GUARD FROM FOREIGN PARTICLES AND INSECTS EYELASH – KEEP SWEAT OUT OF YOUR EYES SENSORY RECEPTORS NERVES AT EACH FOLLICLE CAN CAUSE GOOSEBUMPS,

12. GLANDS SEBACEOUS GLANDS MAKE OIL (SEBUM) SWEAT GLANDS APOCRINE – ASSOCIATED WITH HAIR FOLLICLES STINKY AND STICKY SWEAT MEROCRINE – DIRECTLY ONTO SURFACE COOLING WATER, ELECTROLYTES AND METABOLIZED DRUGS PROTECT FROM ENVIRONMENTAL CHEMICALS MAMMARY GLANDS ARE ALSO RELATED TO APOCRINE GLANDS AND ARE PART OF INTEGUMENT….

13. NAILS LOTS OF SENSATION AT FINGER TIPS EXPOSED DORSAL TIPS PROTECT FROM MECHANICAL/ PHYSICAL STRESS DEEPEST PART CLOSE TO BONE ! BODY OF NAIL IS DEAD CELLS PACKED WITH KERATIN NAILS REFLECT HEALTH AND CAN HAVE DISCOLORATION OR RIDGES BASED ON DISEASE AND/OR MALNUTRITION.

14. INJURY REPAIR CLOT/ SCAB STARTS INTERNALLY GRANULATION TISSUE IS NEXT DERMAL RECOVERY EPITHELIAL CELLS REPLACED ENHANCED CIRCULATION FINALLY SCAR TISSUE HIGHLY FIBROUS FEWER CAPILLARIES FOLLICLES, GLANDS AND NERVES ARE NOT REPAIRED