biol 121 chp 5: the integumentary system
DESCRIPTION
This is a lecture presentation for my BIOL 121 Anatomy and Physiology I students on Chapter 5: The Integumentary System (Principles of Anatomy and Physiology, 14th Ed. by Tortora and Derrickson). Rob Swatski, Associate Professor of Biology, Harrisburg Area Community College - York Campus, York, PA. Email: [email protected] Please visit my website for more anatomy and biology learning resources: http://robswatski.virb.com/TRANSCRIPT
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The Integumentary System
BIOL 121: A&P I Chapter 5
Rob Swatski Associate Professor of Biology
HACC – York Campus Textbook images - Copyright © 2014 John Wiley & Sons, Inc. All rights reserved.
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Integumentary System
Skin
Epidermis Dermis Hypodermis
Accessory structures
Hair Glands Nails
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4
FuncLons of Integumentary System
Protec5on Regula5on Sensory input
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6
Epidermis Most
superficial layer
Stra5fied squamous epithelium
5 main layers (strata)
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Dermis
Thickest layer
Dense irregular CT
Accessory structures
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Hypodermis Deepest layer
Areolar CT & adipose
Stores energy
Regulates temperature
Blood vessel & nerve passage
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11
Overview of the Epidermis
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4 Main Cells of the Epidermis
KeraLnocytes Melanocytes
Langerhans cells
(Intraepidermal macrophages)
Merkel cells (TacLle
epithelial cells)
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KeraLnocytes
Kera5n
Lamellar granules
Cell junc5ons
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Melanocytes
Melanin
Skin color pigment
Absorbs UV
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Langerhans Cells
Develop in bone
marrow
Immune func5on
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Merkel Cells
On Merkel (tac5le) discs
Respond to touch s5muli
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Layers (Strata) of the Epidermis
Stratum corneum
Stratum lucidum*
Stratum granulosum
Stratum spinosum
Stratum basale
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(d) Sectional view of dermal papillae, epidermal ridges, and epidermal layers
Epidermal ridge
Corpuscle of touch in dermal papilla
LM 250x
Stratum corneum
Stratum lucidum
Stratum granulosum
Stratum spinosum
Stratum basale
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Stratum Basale
Deepest layer
Ac5ve mitosis
Tonofilaments
Desmosomes
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Desmosomes
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Stratum Spinosum
8-‐10 layers
“Spiny”
Strong & flexible
Absorbs melanin
Desmosomes
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Stratum Granulosum
3-‐5 layers
Transi5on zone
Flat, dying cells
(apoptosis)
Lamellar granules
Keratohyalin granules
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Stratum Lucidum
4-‐6 layers
Clear, flat, dead cells
Finger5ps, palms, soles
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Stratum Corneum
25-‐30 layers
Flat, dead cells
Rich in kera5n & lipids
Constantly shed
Strong barrier
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Growth of Epidermis
Stratum basale (stem cells)
Mitosis
Kera5niza5on
Epidermal Growth
Factors (EGFs)
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Psoriasis
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Skin graVs
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Dermis CT: collagen, elas5c fibers, adipose
Papillary & Re5cular regions
Fibroblasts & macrophages
Hair follicles & glands
Blood vessels & nerves
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Papillary Region
Areolar CT Adipose Hair
follicles Glands Sensory receptors
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FuncLons of Papillary Region
Strength
Elas5city
Extensibility
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Sensory receptors
Paccinian corpuscles
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Epidermal Ridges
sweat pores
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ReLcular Region
Dense irregular CT: collagen!
Adipose Hair follicles Glands Sensory receptors
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42 stretch marks
Lines of cleavage
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Skin Color
Jaundice Cyanosis Erythema
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Jaundice Yellowish skin/eye color
Bilirubin build-‐up
Liver disease
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Cyanosis
Bluish color to skin/nails
Hemoglobin deple5on
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Erythema
Redness of skin
Dermal capillary
enlargement
Inflamma5on, infec5on, burns
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InflammaLon
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Melanocytes Tyrosine Melanin
(results may vary)
Melanin ProducLon
Freckles Albinism Vi5ligo
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Freckles
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Albinism
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ViLligo
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Papa Smurf is real…
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Accessory Structures
Hair (Pili)
Nails
Sudoriferous glands
Sebaceous glands
Ceruminous glands
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Hair (pili)
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FuncLons of Hair
Insula5on
UV protec5on
Protects eyes
Touch sensa5on (hair root plexus)
(b) Several hair shafts showing the shinglelike cuticle cells
Hair shaft
SEM 70x
Epidermal cells
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Anatomy of Hair
ShaV
Medulla Cortex Cu5cle
Root
Internal & external sheaths
Hair Follicle
Bulb Matrix
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Hair follicle
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(c) Frontal and transverse sections of hair root
Hair root:
Medulla
Cortex
Cuticle of the hair
Hair follicle: Internal root sheath
External root sheath
Epithelial root sheath
Dermal root sheath External root sheath Internal root sheath
Epithelial root sheath Cuticle of the hair
Cortex Medulla Hair matrix Melanocyte Papilla of the hair Blood vessels
Bulb
Dermal root sheath
(d) Transverse section of hair root
Hair root:
Cuticle of the hair Cortex
Medulla
Dermal root sheath
Internal root sheath
External root sheath
Epithelial root sheath
Hair follicle:
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Surrounding Structures of
Hair
Arrector pili
Hair root plexus
Sebaceous glands
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Types of Hair
Lanugo
Vellus
Terminal
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Lanugo
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Vellus
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Terminal hair
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Terminal hair
73 Demodex
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Blinky
Growing Stage
ResLng Stage
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Hair Growth Cycle
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Hair Color
Dark hair
Blonde & Red hair
Graying hair
White hair
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Sudoriferous Glands
Eccrine
Apocrine
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Eccrine gland
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Eccrine gland
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Apocrine gland
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Sebaceous Glands Near hair follicles
Produce sebum
Moistens hair
Waterproofs skin
Inhibits bacteria growth
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Sebaceous gland
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Sebaceous gland
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Ceruminous Glands In external
auditory meatus
Produce cerumen
Physical barrier
An5microbial
Lubrica5on
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Nails
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Structure of Nails
Free edge
Nail body
Lunula
Eponychium (cu5cle)
Nail root w/ matrix
Free edge
Nail body (plate)
Lunula
Eponychium (cuticle) Nail root
(a) Dorsal view
NAIL ROOT is the portion that is not visible
(b) Sagittal section showing internal detail
EPONYCHIUM (cuticle) is the stratum corneum of the epidermis
LUNULA is the thick, white part of the nail
NAIL BED is the skin below the nail plate
Sagittal plane
FREE EDGE extends past the finger or toe
HYPONYCHIUM secures nail to the fingertip
Epidermis
Dermis
Phalanx (finger bone) NAIL MATRIX is the epithelium proximal to the nail
root. It contains dividing cells, which produce new nail cells
NAIL BODY is the visible portion of
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Thin Skin
< 0.5 mm
Covers most of body
No epidermal ridges
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Thick Skin
0.5 -‐ 5 mm
Palms, soles, digits
Epidermal ridges
Stratum lucidum
No hair follicles, sebaceous glands
FuncLons of Skin
Cutaneous SensaLon
Thermo-‐regulaLon
Blood reservoir
ProtecLon -‐ Physical -‐ Chemical -‐ Biological
ExcreLon and
AbsorpLon
Vitamin D synthesis -‐ calcitriol
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Thermo-‐regulaLon
PerspiraLon
Evapora5on
Cooling
Shivering
Vasoconstric5on
Warming
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Epidermal Wound Healing
MigraLon
InhibiLon
Thickening
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MigraLon
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InhibiLon & Thickening
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Deep Wound Healing
InflammaLon
MigraLon
ProliferaLon
MaturaLon
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InflammaLon
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MaturaLon
102 Hypertrophic scar
Fibrosis
Keloid scar 103
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Collagen fibers
ElasLc fibers
Fibroblasts
Melanocytes
Langerhans cells
Phagocytes
Effects of
Aging
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Wrinkling
Dryness & cracking
Blood vessel walls thicken
Subcutaneous fat lost
…There’s More!
106 Photodamage
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Cancer
Hyperplasia
Tumor (Neoplasm)
Benign
Malignant
Normal cells
Tumor-‐forming cells
108 Cancer cell
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Carcinogenesis
Carcinogens: x-‐rays, viruses, toxins
Gene muta5ons
Metastasis
Angiogenesis
110 Metastasis
Types of Cancer
Carcinoma Melanoma Sarcoma Leukemia Lymphoma
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112
Skin Cancer
Basal cell carcinoma
Squamous cell carcinoma
Malignant melanoma
113 Basal cell carcinoma
114 Squamous cell carcinoma
115 Malignant melanoma
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Normal nevus (mole)
Malignant melanoma
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Risk Factors for Skin Cancer
Skin type
Sun exposure
Family history
Age
Immune health
119
Treatment of Cancer
Chemotherapy
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RadiaLon therapy
121
Burns
Heat, electricity, radia5on, chemicals
Systemic vs. local effects
Severity: depth, area, age, health
Shock, circulatory & kidney problems,
infec5on
Rule of nines
122
Burn ClassificaLon
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1st Degree Burn
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2nd Degree Burn
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3rd Degree Burn
127
Rule of Nines
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Pressure Sore (DecubiLs ulcer)