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Skin ap
The integumentary system consists of the skin and its structures that protect the body from damage, regulate temperature and water balance, and synthesize vitamin D. The skin is composed of three main layers - the epidermis, dermis and subcutaneous layer. The epidermis contains keratinized stratified squamous epithelium and provides a protective barrier. The dermis contains blood vessels, hair follicles, and glands. The subcutaneous layer consists of connective tissue and adipose tissue. Accessory structures include hair, nails, sebaceous glands and sweat glands. The integumentary system helps regulate body temperature through vasodilation, sweating and shivering.
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Skin ap
- 1. PowerPoint Lecture Integumentary System Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
- 2. Introduction • Two ormore kinds of tissues grouped together and performing specialized functions constitutes an organ. • The skin and its various structures make up the integumentary system. 2
- 3. Skin and ItsTissues • Composed of several tissue types • Maintains homeostasis • Protective covering • Retards water loss • Regulates body temperature • Houses sensory receptors • Contains immune system cells • Synthesizes chemicals (such as vit D) • Excretes small amounts of wastes 3
- 4. Layers of Skin(2) Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. • Epidermis Stratified squamous • Dermis epithelium • Subcutaneous layer • aka hypodermis Dense irregular connective • beneath dermis tissue • some also call it the superficial fascia • not part of the Adipose tissue skin © The McGraw-Hill Companies, Inc./Al Telser, photographer 4
- 5. Epidermis Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. • Lacks blood vessels Hair shaft • Keratinized Sweat gland pore Sweat Stratum corneum Epidermis Stratum basale • Thickest on palms and Capillary Dermal papilla Basement membrane soles (0.8-1.4mm) Dermis TTactile (Meissner’s) corpuscle Sebaceous gland Arrector pili muscle • Melanocytes provide Sweat gland duct Lamellated (Pacinian) corpuscle Hair follicle melanin Subcutaneous layer Sweat gland Nerve cell process • Rests on basement membrane Adipose tissue Blood vessels Muscle layer • Stratified squamous epithelia (a) Hair shaft Epidermis Hair follicle Dermis Sebaceous gland (b) 5 b: © Victor Eroschenko
- 6. 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) 6 b: © The McGraw-Hill Companies, Inc./Al Telser, photographer
- 7. Epidermis • Heredity andenvironment determine skin color • Genetic Factors • Physiological Factors • Varying amounts of melanin • Dilation of dermal blood vessels • Varying size of melanin • Constriction of dermal blood granules vessels • Albinos lack melanin • Accumulation of carotene • Jaundice • Environmental Factors • Cyanosis • Sunlight • UV light from sunlamps • X-rays • Darkens melanin 7
- 8. Dermis • On average1.0-2.0mm thick • Contains dermal papillae Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. • Binds epidermis to underlying Hair shaft Sweat gland pore Sweat tissues Epidermis Stratum corneum Stratum basale Capillary • Irregular dense connective tissue Dermal papilla Basement membrane • Muscle cells – arrector pili Tactile (Meissner’s) corpuscle Dermis Sebaceous gland Arrector pili muscle Sweat gland duct • Nerve cell processes Lamellated (Pacinian) corpuscle Hair follicle • Specialized sensory receptors SubcutaneousSubcutaneous Sweat gland layer Nerve cell process Adipose tissue Blood vessels • Blood vessels (a) Muscle layer • Hair follicles • Glands 8
- 9. Dermis • There areactually two (2) layers to the dermis: Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. • Papillary layer • thin Hair shaft Sweat gland pore Sweat • superficial Epidermis Stratum corneum Stratum basale • dermal papillae here Capillary Dermal papilla • loose areolar CT Dermis Basement membrane Tactile (Meissner’s) corpuscle Sebaceous gland Arrector pili muscle • Reticular layer Sweat gland duct Lamellated (Pacinian) corpuscle • 80% of dermis Hair follicle SubcutaneousSubcutaneous Sweat gland layer Nerve cell process • dense irregular CT Adipose tissue Blood vessels Muscle layer (a) 9
- 10. Subcutaneous Layer • Akahypodermis Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. • Loose connective Hair shaft Sweat gland pore Sweat tissue and … Epidermis Stratum corneum Stratum basale Capillary Dermal papilla • Adipose tissue Dermis Basement membrane Tactile (Meissner’s) corpuscle Sebaceous gland are present Arrector pili muscle Sweat gland duct Lamellated (Pacinian) corpuscle • Insulates Subcutaneous Hair follicle Sweat gland layer Nerve cell process Adipose tissue • Major blood Blood vessels Muscle layer vessels present (a) 10
- 11. Accessory Structures of the Skin • Accessory structures of the skin originate from the epidermis and include: • Hair follicles • Nails • Skin glands 11
- 12. Hair Follicles Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. • Epidermal cells Hair shaft • Tube-like depression Pore • Extends into dermis • Three (3) parts: Sebaceous gland • Hair root • Hair shaft Arrector pili muscle Hair root • Hair papilla (keratinized cells) Hair follicle • Melanin Eccrine sweat gland Region of • Arrector pili muscle cell division Hair papilla DermalDermal blood vessels (a) 12
- 13. 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 13
- 14. Sebaceous Glands Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. • Usually associated with hair Sebaceous gland follicles Hair follicle • Holocrine glands • Secrete sebum (oil) Hair • Absent on palms and soles © Per H. Kjeldsen 14
- 15. Sweat Glands Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. • Aka sudoriferous glands Hair shaft • Widespread in skin Pore • Originates in deeper dermis Dermal papilla or hypodermis Sebaceous gland • Eccrine glands Duct Hair • Apocrine glands follicle Eccrine sweat • Ceruminous glands gland Apocrine sweat • Mammary glands gland 15
- 16. Regulation of Body Temperature • Regulation of body temperature is vitally important because even slight shifts can disrupt metabolic reactions. 16
- 17. 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 Effectors Thermoreceptors Dermal blood vessels send signals to the dilate and sweat glands control center. secrete. Stimulus Response Body temperature rises Body heat is above normal. lost to surroundings, temperature drops toward normal. too high Normal body temperature 37°C (98.6°F) too low Stimulus Response Body temperature Body heat is conserved, drops below normal. temperature rises toward normal. Receptors Effectors Effectors Thermoreceptors Dermal blood Dermal blood send signals to the vessels constrict vessels constrict control center. and sweat glands and sweat glands remain inactive. remain inactive. Control center Hypothalamus detects the deviation from the set point and signals effector organs. If body temperature continues to drop, control center signals 17 muscles to contract involuntarily.
- 18. Heat Production andLoss • 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 18
- 19. Problems in Temperature Regulation • Hyperthermia – abnormally high body temperature • Hypothermia – abnormally low body temperature 19
- 20. Healing of Woundsand 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 20
- 21. 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 21 (f) (g)
- 22. Types of Burns •First degree burn – superficial, partial-thickness • Second degree burn – deep, partial-thickness • Third degree burn – full-thickness 22
- 23. Rule of Ninesfor Adults Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Anterior head 41/2% Anterior and posterior head and neck 41/ 2% Posterior head and neck 41/2% 9% and neck 41/2% Anterior Anterior and Posterior trunk posterior upper trunk 18% extremities 18% 18% Anterior upper Anterior and Posterior upper extremities 9% posterior trunk extremities 9% 36% 41/ 2% 41/2% 41/2% 41/ 2% Perineum 1% 9% 9% 9% 9% Anterior lower Anterior and Posterior lower extremities 18% posterior lower extremities 18% extremities 36% 23 100%
- 24. Lifespan Changes • Skinbecomes scaly • Melanin production slows • Age spots appear • Hair thins • Epidermis thins • Number of hair follicles • Dermis becomes decreases reduced • Nail growth becomes • Loss of fat impaired • Wrinkling • Sensory receptors decline • Sagging • Body temperature unable to • Sebaceous glands be controlled secrete less oil • Diminished ability to activate Vitamin D 24