Chapter 4: Integumentary System
Entry Task
1/7
Brainstorm AND record 3 possible functions
of the integumentary (skin) system…
Wednesday
1/7
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Mini-Quiz: Body Tissues
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Begin CH 4: Skin & Body Membranes
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Worksheet: Skin Structure
Take notes from PowerPoint
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Integumentary System
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Function
p.108-114
Melanin
Skin & Body Membranes
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Epithelial tissue membrane (3 types)
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Cutaneous
 Stratified squamous on a layer of dense
fibrous connective tissue
Mucous
 Stratified squamous on simple columnar
Serous
 Simple squamous on areolar tissue
A Closer Look at the Serosa…
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Parietal layer
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lines ventral cavity, folds on itself to form visceral
layer
Visceral layer
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covers outside of organs in cavity
Serous fluid fills the pocket
The Serosa
Skin & Body Membranes, cont…
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Connective tissue
membranes
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Synovial
 Soft areolar
connective tissue
 NO epithelial cells
Functions of I.S.
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Protects from:
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Mechanical, chemical, bacterial, UV, thermal, &
dessication
Heat loss/retention
Excretion of urea/uric acid
Makes Vitamin D
Tells us about external environment
Structure
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Epidermis
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Dermis
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Stratified squamous
Dense fibrous conn. tissue
Hypodermis
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Adipose tissue
Firmly connected
together!
Skin Structure
Epidermis
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5 layers called “strata” (deep to superficial)
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stratum basale
stratum spinosum
stratum granulosum
stratum lucidum
stratum corneum
Avascular—no blood supply
Keratinocytes—produce keratin
Epidermis of Thick Skin
A Closer Look at the Strata…
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Stratum basale
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Stratum spinosum
Stratum granulosum
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Cells become flatter, full of keratin
Stratum lucidum
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deepest layer
receives nutrients
constantly dividing
Cells beginning to die, extra thick, hairless skin
Stratum corneum
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DEAD!!!
20-30 cell layers thick
Fun Facts
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Every 25-45 days, you have a completely
NEW epidermis!
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Everything you see when you look at
someone else is DEAD! Gross!
Melanin
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Melanin is a pigment
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yellow to brown to black
Melanocytes make the pigment
Freckles/moles
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Melanin is concentrated in 1 area
Dermis
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Your dermis is your “hide”
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Strong, stretchy envelope
Dense fibrous conn. tissue
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Collagen
Elastic fibers
2 Regions:
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Papillary layer—upper dermis
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House pain receptors/free nerve endings & touch receptors
(Meissner’s corpuscles)
Reticular layer—deepest skin layer
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Pressure receptors (Pacinian corpuscles)
Dermis, continued…
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Blood Vessels—maintain homeostasis
Rich nerve supply
Entry Task
1.
2.
3.
1/8
Explain the function of the stratum basale of the
epidermal layer.
Why do we get wrinkled, saggy skin as we age? Be
sure to identify the layer of skin involved in your
answer.
What part of skin do you think pain receptors are
found in? Touch receptors?
Skin Color
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3 Pigments
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Melanin
Carotene
Oxygen-rich hemoglobin
Alterations in skin color
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redness/erythema
pallor/blanching
jaundice
bruises
Appendages of the Skin
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Includes:
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cutaneous glands, hair, hair follicles, and nails
Exocrine glands—release secretions through
ducts
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2 Types
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Sebaceous glands (oil)
Sudoriferous glands (sweat)
Sebaceous Glands (Oil)
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All over skin (not on palms/feet)
Empties into hair follicles
Secretes sebum—oil & fragmented cells
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Keeps skin soft
Has chemicals that kill bacteria
Clogged duct = whitehead
Sudoriferous Glands (sweat)
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2.5 million/person
2 Types: Eccrine & Apocrine
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Eccrine
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More common, produces sweat
Heat regulation
7L sweat on a hot day!
Sudoriferous Glands, cont…
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Apocrine
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Mainly in axillary & genital area
Larger than eccrine glands
Secretes fatty acid/protein along with other
components
Bacteria have a hay day!!!
Hair & Hair Follicles
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Components:
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Follicle: produces hair
Shaft: part of hair exposed to environment
Root: part of hair enclosed in the follicle
Medulla: central core
Cortex: area between medulla & cuticle
Cuticle: heavily keratinized; shingles
Arrector pili: smooth muscle, connects follicle to
tissue
Matrix: growth zone
Hair bulb: contain melanocytes
Nails
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Components:
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Free edge
Body
Root: embedded in skin
Nail folds: sides of nails, connected to skin
Cuticle: thick proximal nail fold
Lunula: crescent
Nail bed: extends beneath the nail
Nail matrix: thick part of nail bed; growth
Homeostatic Imbalances
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Over 1000 ailments of the skin!
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Mostly allergies, fungus, burns, & cancer
Athlete’s foot—fungus
Boils/carbuncles—inflamed oil glands
Cold sores—herpes virus
Contact dermatitis—chemical contact
Impetigo—bacterial infection
Psoriasis—autoimmune disorder
Burns
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Def: Tissue damage/cell death caused by
intense heat
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Skin = thick as a paper towel
Almost all body systems suffer when skin is
burned
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2 life threatening problems: fluid loss &
kidney shutdown/circulatory shock
Burns, cont…
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Rule of Nines:
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Body divided into 11 areas, each covering 9%
surface area
Helps determine volume of fluid lost
Infection is leading cause of death
Burns are sterile 24 hours after
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Then pathogens invade
Burn Classification
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1° Burn
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Epidermis damaged
Red, swollen
Lasts 2-3 days
EX: sunburn
Burn Classification
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2° Burn
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Epidermis & Upper
Dermis damaged
Red, painful blisters
Regrowth can occur
No permanent
scarring if taken care
of
Burn Classification
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3° Burn
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Entire thickness of
skin destroyed
Blanched/Black
No pain—nerves
destroyed
Regeneration not
possible
Skin grafting
Burn Classification
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CRITICAL burns meet this criteria:
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25+% of the body has 2° burns
10% has 3° burns
3° burns on the face, hands, and/or feet
Skin Cancer
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Most common of all cancers
1 in 5 people will have skin cancer in their
lifetime
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3 Types
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Basal cell carcinoma
Squamous cell carcinoma
Malignant melanoma
Basal Cell Carcinoma
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Least malignant, most
common
No keratin/boundary
formed by stratum
basale
Invades
dermis/hypodermis
On face, shiny, slowgrowing
Full cure @ 99% in
most cases
Squamous Cell Carcinoma
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Stratum spinosum
Scaly, reddened papule
Shallow ulcer, raised
border
Scalp, ears, hands, lips
Fast growing
If caught early full
recovery can be made
Malignant Melanoma
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Cancer of melanocytes
5+% cases are
melanoma
Appears
spontaneously,
develops from
pigmented moles
brown to black patches
50% survival rate
ABCD Rule
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Asymmetry
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Border irregularity
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Borders not smooth, have indents
Color
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2 sides of mole/spot don’t match
Different colors, range from black/brown/tan,
blues/reds
Diameter
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6+ mm
Thursday
3/27
Identify different types of burns and skin cancers
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Finish PowerPoint Notes
Begin Review assignment
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P.127 MC: #1-2, 4, 6-7; SA: #1-4, 6-11, 13;
At the Clinic: #1-4
Friday
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Correct Review
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Play Flyswatter
Review game
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Test over all of CH
4 on Monday after
break!
3/28
Have a Great Spring Break!