Ch 4 Skin Power Point

Skin Intro Activity – Touch
1. Working in pairs
2. Individual #1 is blindfolded while #2 lays out sandpaper
squares on desk.
3. Individual #1 must use fingers only to feel the squares & place
the squares in order from most rough to most smooth.
4. #2 will record the order they were placed in
5. Repeat steps 2-4 only this time #1 must use their elbow to feel
so #2 must rub the squares against the elbow of #1. (#2 must
be sure to shuffle the squares first)
6. Now switch who is blindfolded & repeat.
7. Record your data in the table on the laptop so we can share
as a class.


Data – Pd 4 A & P
Order with fingers Correct? Correct?


Lost in the Desert – Case Study

•Words to define:
•Heat stroke
•First degree burns
•Electrolytes
•Glucose
•Melanin


DIN Wed Oct 19
Based upon what you have learned about Brownian motion &
diffusion, which way, if any, do you think water will move & why?
a. It won’t
b. Both directions but more will move toward side B
c. Both directions but more will move toward side A

A B


DIN
1. Which side
has more
free water
molecules?
2. Which side
has more
solute?
3. Which way
will water
move?
4. What is the
name of the
process
that is
occurring
here?


Understanding & applying terms:
1. solution is hypertonic?
2. Which solution is hypotonic?
3. Which solution is isotonic?
4. Which way will water move? If distilled water were
given in IV:


Skin & Body Membranes
Classification of Body Membranes
1. Explain that skin is one of several different types of body membranes.
Integumentary System (Skin)
2. List several important functions of the integumentary system and explain how these
functions are accomplished.
3. When provided with a model or diagram of the skin, recognize and name the following
skin structures: epidermis, dermis (papillary and reticular layers), hair and hair follicle,
sebaceous gland, and sweat gland.
4. Name and identify the layers of the epidermis and describe the characteristics of each.
5. Describe the distribution and function of the epidermal derivatives-sebaceous glands,
sweat glands, and hair.
6. Explain the importance of keratin and state what layer of skin it is present in.
7. Name the factors that determine skin color and describe the function of melanin.
8. Differentiate between first-, second-, and third-degree burns.
9. Summarize the characteristics of basal cell carcinoma, squamous cell carcinoma, and
malignant melanoma.
10. Briefly describe the following related to skin: psoriosis, jaundice, pallor, erythema,
bruising, decubitus ulcers, male pattern baldness, contact dermatitus,
Developmental Aspects of Skin and Body Membranes
11. List several examples of integumentary system aging.

Use the informational article on skin to determine the various
layers.


Use the informational article on skin to determine the various layers.


Integumentary System
•Skin (cutaneous membrane)
•Skin derivatives
•Sweat glands
•Oil glands
•Hair
•Nails


Skin Functions

•Protects deeper tissues from:
•Mechanical damage (bumps)
•Chemical damage (acids and bases)
•Bacterial damage
•Ultraviolet radiation (sunlight)
•Thermal damage (heat or cold)
•Dessication (drying out)


Skin Functions Continued
• Aids in body
heat loss or
heat retention
as controlled by
the nervous
system
• Aids in excretion
of urea and uric
acid
• Synthesizes
vitamin D


Skin Structure – 3 major layers
• Epidermis—outer layer
• Stratified squamous epithelium
• Keratinized (hardened by keratin) to prevent water loss
• Avascular
• Most cells are keratinocytes
• Dermis – middle layer
• Dense connective tissue
• Subcutaneous tissue (hypodermis) is deep to dermis
• Not technically part of the skin
• Anchors skin to underlying organs
• Composed mostly of adipose tissue
• Insulates

Layers of the Epidermis
• Stratum basale (stratum germinativum)
• Deepest layer of epidermis
• Lies next to dermis
• Wavy borderline with the dermis anchors the two together
• Cells undergoing mitosis
• Daughter cells are pushed upward to become the more superficial
layers
• Stratum spinosum
• Stratum granulosum


Layers of the Epidermis Continued

•Stratum lucidum
•Formed from dead cells of the deeper strata
•Occurs only in thick, hairless skin of the
palms of hands and soles of feet
•Stratum corneum
•Outermost layer of epidermis
•Shingle-like dead cells are filled with keratin
(protective protein prevents water loss from
skin)


Layers of the Epidermis
• Summary of layers from deepest to most superficial
• Stratum basale
• Stratum spinosum
• Stratum granulosum
• Stratum lucidum
• (thick, hairless skin only)
• Stratum corneum


Melanin
• Pigment (melanin) produced by melanocytes
• Melanocytes are mostly in the stratum basale
• Color is yellow to brown to black
• Amount of melanin produced depends upon genetics and
exposure to sunlight


Keratinocytes
Epidermal
Desmosomes dendritic cell

Stratum corneum. Cells are dead;
represented only by flat membranous
sacs filled with keratin. Glycolipids in
extracellular space.
Stratum granulosum. Cells are
flattened, organelles are deteriorating;
cytoplasm full of granules.

Stratum spinosum. Cells contain thick
bundles of intermediate filaments
made of pre-keratin.

Stratum basale. Cells are actively
Merkel dividing stem cells; some newly
cell formed cells become part of the more
superficial layers.

Sensory Dermis
Melanocytes Melanin nerve
granules ending
© 2012 Pearson Education, Inc. Figure 4.4

Layers of the Dermis
• Two layers
• Papillary layer (upper dermal region)
• Projections called dermal papillae
• Some contain capillary loops
• Others house pain receptors and touch receptors
• Reticular layer (deepest skin layer)
• Blood vessels
• Sweat and oil glands
• Deep pressure receptors


• Overall dermis structure
• Collagen and elastic fibers located throughout the dermis Dermis
• Collagen fibers give skin its toughness
• Elastic fibers give skin elasticity
• Blood vessels play a role in body temperature regulation


Epidermis

Papillary layer
of dermis

Reticular layer
of dermis

© 2012 Pearson Education, Inc. Figure 4.5

Normal Skin Color Determinants
• Melanin
• Yellow, brown, or
black pigments
• Carotene
• Orange-yellow
pigment from some
vegetables
• Hemoglobin
• Red coloring from
blood cells in dermal
capillaries
• Oxygen content
determines the extent
of red coloring

Alterations in Skin Color
• Redness (erythema)—due to embarrassment, inflammation,
hypertension, fever, or allergy
• Pallor (blanching)—due to emotional stress such as fear,
anemia, low blood pressure, impaired blood flow to an area
• Jaundice (yellowing)—liver disorder
• Bruises—hematomas


Skin Appendages
• Cutaneous glands are all exocrine glands
• Sebaceous glands
• Sweat glands
• Hair
• Hair follicles
• Nails


Appendages of the Skin – Oil Glands
• Oil (sebaceous) glands Sweat
pore

• Produce oil (sebum) Sebaceous Eccrine
gland gland
• Lubricant for skin
• Prevents brittle
hair
• Kills bacteria
• Most have ducts that
empty into hair Dermal connective
tissue
follicles; others open Sebaceous
directly onto skin gland duct
Hair in
surface hair follicle
• Glands are activated Secretory cells

at puberty

(a) Photomicrograph of a sectioned
© 2012 Pearson Education, Inc. sebaceous gland (14×)
Figure 4.7a

Appendages of the Skin – Sweat Glands
Sweat
• Sweat pore
(sudoriferous) Sebaceous Eccrine
gland gland
glands
• Produce
sweat
• Widely
Dermal connective
distributed tissue
Eccrine
in skin gland duct

Secretory cells

(b) Photomicrograph of a
sectioned eccrine
gland (180×)


Appendages of the Skin – Sweat Glands Cont.
• Two types of sudoriferous glands
• Eccrine
• Open via duct to pore on skin surface
• Produce sweat (clear)
• Apocrine
• Ducts empty into hair follicles (mostly axillary & genital)
• Begin to function at puberty
• Release sweat that also contains fatty acids and proteins
(milky/yellowish color)


Sweat and Its Function

• Composition
• Mostly water
• Salts and vitamin C
• Some metabolic waste
• Fatty acids and proteins (apocrine only)
• Function
• Helps dissipate excess heat
• Excretes waste products
• Acidic nature inhibits bacteria growth
• Odor is from associated bacteria


Appendages of the Skin - Hair
• Hair
• Produced by hair follicle
• Consists of hard keratinized epithelial cells
• Melanocytes provide pigment for hair color
• Hair grows in the matrix of the hair bulb in stratum
basale


Appendages of the Skin – Associated Hair Structures
• Associated hair structures
• Hair follicle
• Dermal and epidermal sheath surround hair root
• Arrector pili muscle
• Smooth muscle
• Pulls hairs upright when cold
or frightened Hair
shaft
• Sebaceous gland Arrector
• Sudoriferous gland pili
Sebaceous
gland

Hair root
Hair bulb
in follicle

(a)

Appendages of the Skin - Hair
• Notice how the scale-like cells of the cuticle overlap one
another in this hair shaft image (660×)
• The link below shows hair replacement surgery video:
• https://www.youtube.com/watch?v=Y46wSTY1cD4


Appendages of the Skin - Nail
• Nails
• Scale-like
modifications of the
epidermis
• Heavily keratinized
• Stratum basale
extends beneath the
nail bed
• Responsible for
growth
• Lack of pigment
makes them
colorless


Appendages of the Skin – Nail Cont.
• Nail structures
• Free edge
• Body is the visible
attached portion
• Root of nail
embedded in skin
• Cuticle is the proximal
nail fold that projects
onto the nail body


Skin Homeostatic Imbalances

•Burns
•Tissue damage and cell death caused by
heat, electricity, UV radiation, or chemicals
•Associated dangers
•Dehydration
•Electrolyte imbalance
•Circulatory shock


Rule of Nines
• Way to determine the extent of burns
• Body is divided into 11 areas for quick estimation
• Each area represents about 9 percent of total body
surface area Totals
1
4 /2% Anterior and posterior
head and neck, 9%
Anterior and posterior
upper limbs, 18%
1/ %
4 2 1/ % trunk, 36%
4 2
Anterior
trunk, 18%

Perineum, 1%
9% 9%

lower limbs, 36%
100%
(a)
Figure 4.1

Severity of Burns
• First-degree burns
• Only epidermis is
damaged
• Skin is red and swollen
• Second-degree burns
• Epidermis and upper
dermis are damaged
• Skin is red with blisters
• Third-degree burns
• Destroys entire skin
layer; burned area is
painless
• Burn is gray-white or
black

Critical Burns

•Burns are considered critical if
•Over 25 percent of body has second-degree
burns
•Over 10 percent of the body has third-
degree burns
•There are third-degree burns of the face,
hands, or feet


• Infections
• Athlete’s foot (tinea pedis)
• Caused by fungal infection
• Boils
• Caused by bacterial infection
• Cold sores
• Caused by virus


• Infections and allergies
• Contact dermatitis
• Exposures cause allergic reaction
• Impetigo
• Caused by bacterial infection
• Psoriasis
• Cause is unknown
• Triggered by trauma, infection, stress


Skin Cancer
• Cancer—abnormal cell mass
• Classified two ways
• Benign
• Does not spread (encapsulated)
• Malignant
• Metastasized (moves) to other parts of the body
• Skin cancer is the most common type of cancer


Skin Cancer Types
• Basal cell carcinoma
• Least malignant
• Most common type
• Arises from stratum basal


Skin Cancer Types
• Squamous cell carcinoma
• Metastasizes to lymph nodes if not removed
• Early removal allows a good chance of cure
• Believed to be sun-induced
• Arises from stratum spinosum


Skin Cancer Types
• Malignant melanoma
• Most deadly of skin cancers
• Cancer of melanocytes
• Metastasizes rapidly to lymph and blood vessels
• Detection uses ABCD rule


ABCD Rule
• A = Asymmetry
• Two sides of pigmented mole do not match
• B = Border irregularity
• Borders of mole are not smooth
• C = Color
• Different colors in pigmented area
• D = Diameter
• Spot is larger then 6 mm in diameter


Making your own fake burns:
Materials needed:
1.Vaseline
2. toilet tissue
3. ashes (from fire pit or fireplace)
4. Make-up, face paint, tempora paint.
4. Fake blood (the kind that you buy to
harden but it still looks runny is the best)
Directions:
1. Rub vaseline onto an area of skin. You want it
to be kind of thick.
2. Take a thin, jagged piece of toilet tissue (single
layer) and lay on top of vaseline…. This gives
the skin a blistered look.
3. Apply more vaseline, more tissue
4. Use make-up to make the coloring look real…
see following slides for a few examples.


Ch 4 Skin Power Point

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Ch 4 Skin Power Point