Presentation on theme: "The Infamous Integumentary System"— Presentation transcript:
1 The Infamous Integumentary System An insight to your skin, hair, nail, and glands.
2 Fast Facts & Functions Largest organ in body Most visible organ of the bodySkinHairNailsGlandsProtectionMaintain body temperatureStores nutrients (fat)Senses (touch, pain…)Excretion (of salts and water)Secretion (oil, waste, milk)Glands: sweat and sebaceousProtection of tissues and organs underneath; from impact, chemicals, and infections
3 The layers and parts Epidermis Dermis Subcutaneous layers Accessory structuresEpidermis: stems cells attached to basement membrane; projections from underlying CT feed the epidermis; melanocytes are located in the bottom part of epidermis (brown-yellow, brown, and black pigment); these cells respond to sunlight; color “bubbles up; another pigment, carotene, also determines skin color, as well as dermal circulation (dilation of blood vessels)Dermis: papillary layer is made of LCT and has capillaries; Reticular layer is made of dence, irregular CTSubcutaneous layer: made of LCT and fat cells; some fibers from here attach to dermisAccessory structure: hair, sebaceous glands, sweat glands, and nails
4 The outer, epidermis, layer Stratified squamous epitheliaThis epithelia is divided into 5 layers:Stratum germinativumStratum spinosumStratum granulosumStratum lucidumStratum corneumNormally takes 2-4 weeks for cells to move from the bottom to the topSG: deepest layer attached to bm; stem cells and melanocytes lie hereSS: very thick layers of cells, connected by desomozone, cells dividingSGr: cells stop dividing; cytoplasm from the dying cells start to make proteins and enyzmesSL: cells are flattened and packed well; enzymes create the protein, Keratin; cells shed or are washed awaySC: superficial layer of dead epithelia cells and lots of keratinPsoriasis: cells divided very fast so epidermal layer sis replaces every week instead of every 2-4 weeks
5 The middle and inner The middle: Dermis Papillary layer Reticular layerThe inner: Subcutaneous LayerConnective tissue fibersLoose connective tissues and fat cellsPapillary: made of LCT, contains capillaries and nerves, nourished epidermiReticular: mesh of DCT that supports and provides some flexibilitySubcutaneous: children have a layer of body fat all over; this diminishes with growth and changes depending on sex (men: back, neck, upper arms, women: buttocks , hip, breasts); both can get “potbellies”
6 The Accessory Organs Hair Sebaceous glands Sweat glands Nails Originate in dermis and subcutaneous layerKeratinization occursArrector pili: goose bumpsSebaceous glandsOil, waxy substance, fats = sebumSweat glandsDischarge sticky substance; it smells when bacteria breaks it downRelease sweat to cool bodyNailsMade of many dead keratin cellsHair: shaft from skin in dead, keratinized cells; color determined by melanocytes (turns grey as these cells make less melanin)Sebaceous glands: arrector pili muscles contract, squeezing waxy stuff onto skin surface; acne can occur with large sebaceous glands that become blocked, allowing bacteria to infectSweat glands: bacteria break down, making smell; different type of sweat glands (over 3 mill) use their secretions to cool the bodyNails: underlying blood vessels give nail pink color