2 6.1: IntroductionTwo or more kinds of tissues grouped together and performing specialized functions constitutes an organ.The skin and its various structures make up the integumentary system.
3 6.2: Skin and Its Tissues Composed of several tissue types Maintains homeostasisProtective coveringRetards water lossRegulates body temperatureHouses sensory receptorsContains immune system cellsSynthesizes chemicalsExcretes small amounts of wastes
4 Skin CellsHelp produce Vitamin D needed for normal bone and tooth developmentSome cells (keratinocytes) produce substances that simulate development of some white blood cells
8 Epidermis Heredity and environment determine skin color Genetic FactorsVarying amounts of melaninVarying size of melanin granulesAlbinos lack melaninPhysiological FactorsDilation of dermal blood vesselsConstriction of dermal blood vesselsAccumulation of caroteneJaundiceEnvironmental FactorsSunlightUV light from sunlampsX-raysDarkens melanin
20 Heat Production and Loss Heat is a product of cellular metabolismThe most active body cells are the heat producers and include:Skeletal muscleCardiac muscleCells of certain glands such as the liverThe primary means of heat loss is radiationAlso there is conduction, convection and evaporation
21 Problems in Temperature Regulation Hyperthermia – abnormally high body temperature(Heat stress and heat stroke)Hypothermia – abnormally low body temperature(frostbite)
22 6.5: Healing of Wounds and Burns Inflammation is a normal response to injury or stress.Blood vessels in affected tissues dilate and become more permeable, allowing fluids to leak into the damaged tissues.Inflamed skin may become:ReddenedSwollenWarmPainful
26 Animation: Thymine Dimers Formation and Repair Please note that due to differing operating systems, some animations will not appear until the presentation is viewed in Presentation Mode (Slide Show view). You may see blank slides in the “Normal” or “Slide Sorter” views. All animations will appear after viewing in Presentation Mode and playing each animation. Most animations will require the latest version of the Flash Player, which is available at
27 6.6: Lifespan Changes Skin becomes scaly Age spots appear Epidermis thinsDermis becomes reducedLoss of fatWrinklingSaggingSebaceous glands secrete less oilMelanin production slowsHair thinsNumber of hair follicles decreasesNail growth becomes impairedSensory receptors declineBody temperature unable to be controlledDiminished ability to activate Vitamin D
28 Important Points in Chapter 6: Outcomes to be Assessed 6.1: IntroductionDefine organ, and name the large organ of the integumentary system.6.2: Skin and Its TissuesList the general functions of the skin.Describe the structure of the layers of skin.Summarize the factors that determine skin color.6.3: Accessory Structures of the SkinDescribe the accessory structures associated with the skin.Explain the functions of each accessory structure of the skin.
29 Important Points in Chapter 6: Outcomes to be Assessed 6.4: Regulation of Body TemperatureExplain how the skin helps regulate body temperature.6.5: Healing of Wounds and BurnsDescribe the events that are part of wound healing.Distinguish among the types of burns, including a description of healing with each type.6.6: Lifespan ChangesSummarize lifespan changes in the integumentary system.