Chapter 6 Lecture PowerPoint To run the animations you must be in Slideshow View. Use the buttons on the animation to play, pause, and turn audio/text on or off. Please Note: Once you have used any of the animation functions (such as Play or Pause), you must first click in the white background before you can advance to the next slide. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Type Institution Name Here Type Course Number Here: Type Course Name Here Chapter 6 Type Professor Name Here Type Academic Rank Here Type Department Name Here 2 Hole’s Human Anatomy and Physiology Twelfth Edition Shier w Butler w Lewis Chapter 6 Integumentary System Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 3 6.1: Introduction • Two 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. 4 6.2: Skin and Its Tissues • Composed of several tissue types • Maintains homeostasis • Protective covering • Retards water loss • Regulates body temperature • Houses sensory receptors • Contains immune system cells • Synthesizes chemicals • Excretes small amounts of wastes 5 Skin Cells • Help produce Vitamin D needed for normal bone and tooth development • Some cells (keratinocytes) produce substances that simulate development of some white blood cells 6 Layers of Skin (3) Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. • Epidermis • Dermis • Subcutaneous layer • Aka hypodermis • Beneath dermis • Some also call it the superficial fascia • Some consider it not part of the skin Stratified squamous epithelium Dense irregular connective tissue Adipose tissue © The McGraw-Hill Companies, Inc./Al Telser, photographer 7 Epidermis Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. • Lacks blood vessels • Keratinized • Thickest on palms and soles (0.8-1.4mm) • Melanocytes provide melanin • Rests on basement membrane • Stratified squamous epithelia Hair shaft Sweat gland pore Sweat Stratum corneum Epidermis Stratum basale Capillary Dermal papilla Basement membrane TTactile (Meissner’s) corpuscle Dermis Sebaceous gland Arrector pili muscle Sweat gland duct Lamellated (Pacinian) corpuscle Hair follicle Sweat gland Subcutaneous layer Nerve cell process Adipose tissue Blood vessels Muscle layer (a) Hair shaft Epidermis Dermis Hair follicle Sebaceous gland 8 (b) b: © Victor Eroschenko Epidermis There are five (5) layers of the epidermis: • Stratum corneum • Stratum lucidum • Stratum granulosum • Stratum spinosum • Stratum basale Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Stratum corneum Stratum lucidum Stratum granulosum Stratum spinosum Stratum basale Basement membrane Dermal papilla Dermis (a) (b) b: © The McGraw-Hill Companies, Inc./Al Telser, photographer 9 Epidermis • Heredity and environment determine skin color • Genetic Factors • Physiological Factors • Varying amounts of • Dilation of dermal blood melanin vessels • Varying size of melanin • Constriction of dermal blood granules vessels • Albinos lack melanin • Accumulation of carotene • Jaundice • Environmental Factors • Sunlight • UV light from sunlamps • X-rays • Darkens melanin 10 6.1 Clinical Application Tanning and Skin Cancer 11 Dermis • On average 1.0-2.0mm thick • Contains dermal papillae • Binds epidermis to underlying tissues • Irregular dense connective tissue • Muscle cells • Nerve cell processes • Specialized sensory receptors Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Epidermis Dermis SubcutaneousSubcutaneous layer • Blood vessels • Hair follicles • Glands Hair shaft Sweat gland pore Sweat Stratum corneum Stratum basale Capillary Dermal papilla Basement membrane Tactile (Meissner’s) corpuscle Sebaceous gland Arrector pili muscle Sweat gland duct Lamellated (Pacinian) corpuscle Hair follicle Sweat gland Nerve cell process Adipose tissue Blood vessels Muscle layer (a) 12 Dermis • There are actually two (2) layers to the dermis: Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. • Papillary layer • Thin • Superficial • Dermal papillae here • Reticular layer • 80% of dermis • Cleavage, tension or Langer’s lines are here Hair shaft Sweat gland pore Sweat Stratum corneum Epidermis Stratum basale Capillary Dermal papilla Basement membrane Dermis Tactile (Meissner’s) corpuscle Sebaceous gland Arrector pili muscle Sweat gland duct Lamellated (Pacinian) corpuscle Hair follicle SubcutaneousSubcutaneous layer Sweat gland Nerve cell process Adipose tissue Blood vessels Muscle layer (a) 13 Subcutaneous Layer • Aka hypodermis • Loose connective tissue and … Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Hair shaft Sweat gland pore Sweat Stratum corneum Epidermis Stratum basale Capillary • Adipose tissue are present • Insulates Dermal papilla Basement membrane Dermis Tactile (Meissner’s) corpuscle Sebaceous gland Arrector pili muscle Sweat gland duct Lamellated (Pacinian) corpuscle Hair follicle SubcutaneousSubcutaneous layer Sweat gland Nerve cell process Adipose tissue • Major blood vessels present Blood vessels Muscle layer (a) 14 6.3: Accessory Structures of the Skin • Accessory structures of the skin originate from the epidermis and include: • Hair follicles • Nails • Skin glands 15 Hair Follicles Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. • Epidermal cells • Tube-like depression • Extends into dermis • Three (3) parts: • Hair root • Hair shaft • Hair papilla Hair shaft Pore Sebaceous gland Arrector pili muscle Hair root (keratinized cells) Hair follicle Eccrine sweat gland • Dead epidermal cells • Melanin • Arrector pili muscle Region of cell division Hair papilla DermalDermal blood vessels (a) 16 Nails Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. • Protective coverings Lunula Nail bed Nail plate • Three (3) parts: • Nail plate • Nail bed • Lunula 17 6.2 Clinical Application Hair Loss 18 Sebaceous Glands Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. • Usually associated with hair follicles Sebaceous gland Hair follicle • Holocrine glands • Secrete sebum (oil) Hair • Absent on palms and soles © Per H. Kjeldsen 19 Sweat Glands Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. • Aka sudoriferous glands • Widespread in skin Hair shaft • Originates in deeper dermis or hypodermis • Eccrine glands • Apocrine glands • Ceruminous glands • Mammary glands Pore Dermal papilla Sebaceous gland Duct Hair follicle Eccrine sweat gland Apocrine sweat gland 20 6.3 Clinical Application Acne 21 6.4: Regulation of Body Temperature • Regulation of body temperature is vitally important because even slight shifts can disrupt metabolic reactions. 22 Regulation of Body Temperature Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Control center Hypothalamus detects the deviation from the set point and signals effector organs. Receptors Thermoreceptors send signals to the control center. Effectors Dermal blood vessels dilate and sweat glands secrete. Stimulus Body temperature rises above normal. Response Body heat is lost to surroundings, temperature drops toward normal. too high Normal body temperature 37°C (98.6°F) too low Stimulus Body temperature drops below normal. Receptors Thermoreceptors send signals to the control center. Response Body heat is conserved, temperature rises toward normal. Effectors Dermal blood vessels constrict and sweat glands remain inactive. Control center Hypothalamus detects the deviation from the set point and signals effector organs. Effectors Dermal blood vessels constrict and sweat glands remain inactive. If body temperature continues to drop, control center signals muscles to contract involuntarily. 23 Heat Production and Loss • Heat is a product of cellular metabolism • The most active body cells are the heat producers and include: • Skeletal muscle • Cardiac muscle • Cells of certain glands such as the liver • The primary means of heat loss is radiation • Also there is conduction, convection and evaporation 24 Problems in Temperature Regulation • Hyperthermia – abnormally high body temperature • Hypothermia – abnormally low body temperature 25 6.4 Clinical Application Elevated Body Temperature 26 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. • Inflammed skin may become: • Reddened • Swollen • Warm • Painful 27 Healing of Cuts Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Site of injury Blood cells (a) (b) Scab Blood clot (c) (d) (e) Scab Scar tissue Scar tissue Fibroblasts 28 (f) (g) Types of Burns • First degree burn – superficial, partial-thickness • Second degree burn – deep, partial-thickness • Third degree burn – full-thickness • Autograft • Homograft • Various skin substitutes 29 Rule of Nines for Adults Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 41/2% Anterior and posterior head and neck 9% 41/2% Anterior head and neck 41/2% Anterior trunk 18% Anterior and posterior upper extremities 18% Anterior upper extremities 9% 41/2% 41/2% Anterior and posterior trunk 36% Posterior head and neck 41/2% Posterior trunk 18% Posterior upper extremities 9% 41/2% 41/2% Perineum 1% 9% Anterior lower extremities 18% 9% 9% Anterior and posterior lower extremities 36% 9% Posterior lower extremities 18% 30 100% 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 http://get.adobe.com/flashplayer. 31 6.6: Lifespan Changes • Skin becomes scaly • Age spots appear • Epidermis thins • Dermis becomes reduced • Loss of fat • Wrinkling • Sagging • Sebaceous glands secrete less oil • Melanin production slows • Hair thins • Number of hair follicles decreases • Nail growth becomes impaired • Sensory receptors decline • Body temperature unable to be controlled • Diminished ability to activate Vitamin D 32 Important Points in Chapter 6: Outcomes to be Assessed 6.1: Introduction Define organ, and name the large organ of the integumentary system. 6.2: Skin and Its Tissues List 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 Skin Describe the accessory structures associated with the skin. Explain the functions of each accessory structure of the skin. 33 Important Points in Chapter 6: Outcomes to be Assessed 6.4: Regulation of Body Temperature Explain how the skin helps regulate body temperature. 6.5: Healing of Wounds and Burns Describe 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 Changes Summarize lifespan changes in the integumentary system. 34 Quiz 6 Complete Quiz 6 now! Read Chapter 7. 35