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Integumentary System Chapter 6 6-1.

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Presentation on theme: "Integumentary System Chapter 6 6-1."— Presentation transcript:

1 Integumentary System Chapter 6 6-1

2 Chapter 6 Integumentary System (Skin and accessory organs)
Composed of several tissues Maintains homeostasis Protective covering Retards water loss Regulates body temperature Houses sensory receptors Contains immune system cells Synthesizes chemicals Excretes small amounts of waste 6-2

3 Layers of Skin Epidermis Dermis Subcutaneous layer or hypodermis 6-3

4 Epidermis lacks blood vessels keratinized
thickest on palms and soles, thinnest on eyelid ( mm) melanocytes provide melanin rests on basement membrane stratified squamous 6-4

5 Epidermis Layers of Epidermis stratum corneum stratum lucidum
fully keratinized stratum lucidum only in palms and soles stratum granulosum granular layer stratum spinosum thick layer stratum basale deepest layer, can reproduce 6-5

6 Dermis on average 1.0-2.0mm thick dermal papillae
binds epidermis to underlying tissues irregular dense connective tissue muscle cells nerve cell processes blood vessels hair follicles glands 6-6

7 Subcutaneous Layer (hypodermis)
loose connective tissue adipose tissue insulates major blood vessels 6-7

8 Hair Follicles epidermal cells tube-like depression
extends into dermis hair root reproductive cells hair papilla contains blood vessels hair shaft dead epidermal cells melanin, trichosiderin arrector pili muscle 6-8

9 Nails protective coverings* nail plate nail bed lunula
keratinized epithelial cells nail bed surface of skin lunula most active growing region 6-9

10 Glands Sebaceous Glands usually associated with hair follicles
secrete sebum fatty material and cellular debris keeps hair and skin soft, pliable, waterproof absent on palms and soles 6-10

11 Glands sudoriferous glands (sweat) widespread in skin
deeper dermis or hypodermis eccrine glands most numerous respond to temp elevation duct opens superficially at pore forehead, neck, back apocrine glands develop a scent duct opens into hair follicle active at puberty respond to emotion, pain, arousal axilla, groin, areola ceruminous glands ear wax mammary glands milk 6-11

12 Regulation of Body Temperature
6-12

13 Problems in Temperature Regulation
Hyperthermia – abnormally high body temperature Hypothermia – abnormally low body temperature 6-13

14 Skin Color Genetic Factors Physiological Factors
varying amounts of melanin varying size of melanin granules albinos lack melanin Physiological Factors dilation of dermal blood vessels constriction of dermal blood vessels carotene jaundice Environmental Factors sunlight UV light from sunlamps X rays 6-14

15 Healing Cuts Shallow cuts Deep cuts
Epithelial cells around margin stimulated to undergo mitosis faster than normal Deep cuts Escaping blood forms a clot Mainly fibrin (fibrous protein), blood cells, platelets Tissue fluids seep into clot and dry: scab Fibroblasts migrate to injury and form collagenous fibers that bind the edges of wound Connective tissue releases growth factors to stimulate growth. Blood vessels extend into wound. Phagocytic cells remove dead cells Scab falls off The larger and deeper the injury, the more connective tissue is formed, the more likely scar tissue will be visible

16 Healing of Cuts 6-15

17 Healing of Burns First degree burn – superficial partial-thickness
epidermis only Second degree burn – deep partial-thickness epidermis and some dermis skin grows from surviving accessory organs’ epithelial cells Third degree burn – full-thickness skin must grow from margin of burn autograft homograft various skin substitutes extensive scars 6-16

18 Second Degree Burn Fluid escapes from damaged dermal capillaries forming blister Healing occurs from the epithelial cells of surviving accessory organs. Cells divide and grow out to surface of dermis, spread over it, and forms new epidermis. Eventually skin completely covers area. No scar tissue should form.

19 Third Degree Burn Injured skin becomes dry and leathery
Healing can only occur from the surviving epithelial cells growing inward from the margin of the wound. Auto graft: moving your skin from undamaged area to damaged area. Homograft: using cadaver skin to temporarily cover wound to prevent infection. Various skin substitutes: cultured skin from lab Scar tissue will form

20 Rule of Nines 6-17

21 Life Span Changes Dermis becomes reduced
Loss of fat Inability to control body temperature Hair thins Number of hair follicles decrease Impaired nail growth Sensory receptors decline Less vitamin D production Sebaceous glands secrete less oil Scaly skin Wrinkles Sagging Melanin production slows Age spots 6-18


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