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Chapter 6Lecture
PowerPoint
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2401Anatomy and Physiology I
Chapter 6
Susan Gossett
Department of Biology
Paris Junior College
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Hole’s Human Anatomyand Physiology
Twelfth Edition
Shier Butler Lewis
Chapter 6
Integumentary System
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
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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.
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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
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Skin Cells
• Help produce Vitamin D needed for normal bone and tooth development
• Some cells (keratinocytes) produce substances that stimulate development of some white blood cells
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Layers of Skin
• Epidermis• Dermis• Subcutaneous layer
• A.k.a hypodermis• Beneath dermis
Stratifiedsquamousepithelium
Dense irregularconnectivetissue
Adipose tissue
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© The McGraw-Hill Companies, Inc./Al Telser, photographer
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(a)
Hair shaft
Epidermis
Hair follicle
(b)
Sebaceous gland
Dermis
Sweat
Epidermis
Dermis
Hair shaft
Sweat gland pore
Capillary
Stratum corneum
Stratum basale
Dermal papilla
Arrector pili muscle
Lamellated (Pacinian) corpuscle
Basement membrane
Sebaceous gland
Hair follicle
Sweat gland
Nerve cell process
Adipose tissue
Blood vessels
Muscle layer
Sweat gland duct
Subcutaneouslayer
TTactile (Meissner’s) corpuscle
Epidermis
• Lacks blood vessels• Keratinized• Thickest on palms and
soles (0.8-1.4mm)• Melanocytes provide melanin• Rests on basement membrane• Stratified squamous epithelia
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b: © Victor Eroschenko
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Epidermis
There are five (5) layers of the epidermis:• Stratum corneum• Stratum lucidum (only in thick skin – palms, soles)• Stratum granulosum• Stratum spinosum• Stratum basale
Stratum corneum
Stratum lucidum
Stratum granulosum
Stratum spinosum
Stratum basale
Basementmembrane
Dermis
Dermal papilla
(a) (b)
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b: © The McGraw-Hill Companies, Inc./Al Telser, photographer
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Epidermis
• Genetic Factors• Varying amounts of melanin• Varying size of melanin granules• Albinos lack melanin
• Environmental Factors• Sunlight• UV light from sunlamps• X-rays• Darkens melanin
• Physiological Factors• Dilation of dermal blood vessels• Constriction of dermal blood vessels• Accumulation of carotene• Jaundice
• Heredity and environment determine skin color
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6.1 Clinical Application
Tanning and Skin Cancer
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Dermis
• Contains dermal papillae
• Binds epidermis to underlying tissues• Irregular dense connective tissue
• On average 1.0-2.0mm thick
• Muscle cells
• Nerve cell processes• Specialized sensory receptors
• Blood vessels
• Hair follicles
• Glands
(a)
Sweat
Epidermis
Dermis
Hair shaft
Sweat gland pore
Capillary
Stratum corneum
Stratum basale
Dermal papilla
Arrector pili muscle
Lamellated (Pacinian) corpuscle
Basement membrane
Sebaceous gland
Hair follicle
Sweat gland
Nerve cell process
Adipose tissue
Blood vessels
Muscle layer
Sweat gland duct
Subcutaneouslayer
Tactile (Meissner’s) corpuscle
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Dermis
• Papillary layer• Thin• Superficial• Dermal papillae here
• Reticular layer• 80% of dermis• Cleavage, tension or Langer’s lines are here
• There are actually two (2) layers to the dermis:
(a)
Papillary layer
Reticular layer
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Subcutaneous Layer
• A.k.a hypodermis
• Loose connective tissue and Adipose tissue
• Insulates
• Major blood vessels present
(a)
Sweat
Epidermis
Dermis
Hair shaft
Sweat gland pore
Capillary
Stratum corneum
Stratum basale
Dermal papilla
Arrector pili muscle
Lamellated (Pacinian) corpuscle
Basement membrane
Sebaceous gland
Hair follicle
Sweat gland
Nerve cell process
Adipose tissue
Blood vessels
Muscle layer
Sweat gland duct
Subcutaneouslayer
Tactile (Meissner’s) corpuscle
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6.3: Accessory Structures of the Skin
• Accessory structures of the skin originate from the epidermis and include:
• Hair follicles• Nails• Skin glands
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Hair Follicles
• Epidermal cells
• Tube-like depression
• Extends into dermis
• Three (3) parts:• Hair root• Hair shaft• Hair papilla
• Dead epidermal cells
• Melanin• Arrector pili muscle
(a)
Hair shaft
Pore
Hair root(keratinizedcells)
Arrector pilimuscle
Sebaceousgland
Hair follicle
Region ofcell division
Hair papilla
Eccrinesweat gland
Dermal blood vessels
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Nails
• Protective coverings
• Three (3) parts:• Nail plate• Nail bed
• Lunula
Nail bed Nail plateLunula
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6.2 Clinical Application
Hair Loss
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Sebaceous Glands
• Usually associated with hair follicles
• Holocrine glands
• Secrete sebum (oil)
• Absent on palms and soles
Hair
Sebaceousgland
Hair follicle
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© Per H. Kjeldsen
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Sweat Glands
• A.k.a sudoriferous glands
• Widespread in skin
• Originates in deeper dermis or hypodermis
• Eccrine glands
• Apocrine glands
• Ceruminous glands
• Mammary glands
Dermalpapilla
Sebaceousgland
Duct
Hair shaft
Hairfollicle
Eccrinesweatgland
Apocrinesweatgland
Pore
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6.3 Clinical Application
Acne
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6.4: Regulation of Body Temperature
• Regulation of body temperature is vitally important because even slight shifts can disrupt metabolic reactions.
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Regulation of Body Temperature
If body temperaturecontinues to drop,control center signalsmuscles to contractinvoluntarily.
too high
too low
Normal bodytemperature37°C (98.6°F)
Control centerHypothalamusdetects the deviationfrom the set point andsignals effector organs.
Control centerHypothalamusdetects the deviationfrom the set point andsignals effector organs.
StimulusBody temperature risesabove normal.
EffectorsDermal blood vesselsdilate and sweat glandssecrete.
ResponseBody heat islost to surroundings,temperature drops towardnormal.
EffectorsDermal bloodvessels constrictand sweat glandsremain inactive.
EffectorsDermal bloodvessels constrictand sweat glandsremain inactive.
ResponseBody heat is conserved,temperature rises toward normal.
StimulusBody temperaturedrops below normal.
ReceptorsThermoreceptorssend signals to thecontrol center.
ReceptorsThermoreceptorssend signals to thecontrol center.
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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
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Problems in Temperature Regulation
• Hyperthermia – abnormally high body temperature
• Hypothermia – abnormally low body temperature
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6.4 Clinical Application
Elevated Body Temperature
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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
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(a) (b)
(f) (g)
(c) (d) (e)
Scartissue
Fibroblasts
Scartissue
Blood cells
Site of injury
Scab
Bloodclot
Scab
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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
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Rule of Nines for AdultsCopyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Anteriortrunk18%
Posteriortrunk18%
Anterior upperextremities 9%
Posterior upperextremities 9%
Posterior lowerextremities 18%
Perineum 1%
Anterior andposterior upper
extremities18%
Anterior andposterior lower
extremities36%
100%
Anterior andposterior trunk
36%
Anterior and posterior head and neck9%
Anterior headand neck 41/2%
Posterior headand neck 41/2%
Anterior lowerextremities 18%
9% 9% 9% 9%
41/2%
41/2% 41/2% 41/2% 41/2%
41/2%
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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
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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.
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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.
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Quiz 6
Complete Quiz 6 now!
Read Chapter 7.