Transcript cutaneous membrane - Lemon Bay High School

PowerPoint® Lecture Slide Presentation
by Patty Bostwick-Taylor,
Florence-Darlington Technical College
Skin and Body
Membranes
4
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Body Membranes
 Function of body membranes
 Cover body surfaces
 Line body cavities
 Form protective sheets around organs
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Classification of Body Membranes
 Epithelial membranes
 Cutaneous membranes
 Mucous membranes
 Serous membranes
 Connective tissue membranes
 Synovial membranes
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Epithelial - Cutaneous Membrane
 Cutaneous membrane = skin
 Dry membrane
 Outermost protective boundary
 Superficial epidermis is composed of keratinized
stratified squamous epithelium
 Underlying dermis is mostly dense
connective tissue
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Cutaneous Membranes
Figure 4.1a
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Epithelial - Mucous Membranes
 Surface epithelium type depends on site
 Stratified squamous epithelium (mouth,
esophagus)
 Simple columnar epithelium (rest of digestive
tract)
 Underlying loose connective tissue (lamina
propria)
 Lines all body cavities that open to the exterior
body surface
 Often adapted for absorption or secretion
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Mucous Membranes
Figure 4.1b
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Epithelial - Serous Membranes
 Surface is a layer of simple squamous epithelium
 Underlying layer is a thin layer of areolar
connective tissue
 Lines open body cavities that are closed to the
exterior of the body, protects organs and secretes
lubricating fluids.
 Serous membranes occur in pairs separated by
serous fluid
 Visceral (inner) layer covers the outside of the
organ
 Parietal (outer) layer lines a portion of the wall
of ventral body cavity
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Serous Membranes
Figure 4.1d
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Serous Membranes
 Specific serous membranes
 Peritoneum
 Abdominal cavity
 Pleura
 Around the lungs
 Pericardium
 Around the heart
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Serous Membranes
Figure 4.1c
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Body Membrane - Connective Tissue Membrane
 Synovial membrane
 Connective tissue only
 Lines fibrous capsules surrounding joints
 Secretes a lubricating fluid
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Connective Tissue Membrane
Figure 4.2
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Integumentary System
 Skin (cutaneous membrane)
 Skin derivatives
 Sweat glands
 Oil glands
 Hair
 Nails
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Skin Structure
 Epidermis—outer layer
 Stratified squamous epithelium
 Often keratinized (hardened by keratin)
 Dermis
 Dense connective tissue
 Hypodermis
 Subcutaneous – deep to dermis
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Skin Structure
Figure 4.3
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Skin Structure
 Subcutaneous tissue (hypodermis) is deep to
dermis
 Not part of the skin
 Anchors skin to underlying organs
 Composed mostly of adipose tissue
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Layers of the Epidermis
 Stratum basale (stratum germinativum)
 Deepest layer of epidermis
 Lies next to dermis
 Cells undergoing mitosis
 Daughter cells are pushed upward to become
the more superficial layers
 Stratum spinosum
 Stratum granulosum
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Layers of the Epidermis
 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)
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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
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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
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Dermis
 Two layers
 Papillary layer (upper dermal region)
 Projections called dermal papillae
 Some contain capillary loops
 Other house pain receptors and touch
receptors
 Reticular layer (deepest skin layer)
 Blood vessels
 Sweat and oil glands
 Deep pressure receptors
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Dermis
 Overall dermis structure
 Collagen and elastic fibers located throughout
the dermis
 Collagen fibers give skin its toughness
 Elastic fibers give skin elasticity
 Blood vessels play a role in body temperature
regulation
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Skin Structure
Figure 4.4
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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
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Skin Appendages
 Cutaneous glands are all exocrine glands
 Sebaceous glands
 Sweat glands
 Hair
 Hair follicles
 Nails
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Appendages of the Skin
 Sebaceous glands
 Produce oil
 Lubricant for skin
 Prevents brittle hair
 Kills bacteria
 Most have ducts that empty into hair follicles;
others open directly onto skin surface
 Glands are activated at puberty
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Appendages of the Skin
Figure 4.6a
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Appendages of the Skin
 Sweat glands
 Produce sweat
 Widely distributed in skin
 Two types
 Eccrine
 Open via duct to pore on skin surface
 Apocrine
 Ducts empty into hair follicles
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Appendages of the Skin
Figure 4.6b
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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
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Appendages of the Skin
 Hair
 Produced by hair follicle
 Consists of hard keratinized epithelial cells
 Melanocytes provide pigment for hair color
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Appendages of the Skin
Figure 4.7c
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Appendages of the Skin
 Hair anatomy
 Central medulla
 Cortex surrounds
medulla
 Cuticle on outside of
cortex
 Most heavily
keratinized
Figure 4.7b
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Appendages of the Skin
 Associated hair structures
 Hair follicle
 Dermal and epidermal sheath surround
hair root
 Arrector pili muscle
 Smooth muscle
 Pulls hairs upright when cold or frightened
 Sebaceous gland
 Sweat gland
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Appendages of the Skin
Figure 4.7a
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Appendages of the Skin
Figure 4.8
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Appendages of the Skin
 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
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Appendages of the Skin
 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
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Appendages of the Skin
Figure 4.9
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Six Categories
of Skin Disorders
• Infectious: caused by a pathogen
that infects the skin or enters
through an opening.
•
•
•
•
•
Allergic/Environmental
Trauma/Burns
Cancer
Congenital
Genetic
Skin Homeostatic Imbalances
 Infections
 Athlete’s foot (tinea pedis)
 Caused by fungal infection
 Boils and carbuncles
 Caused by bacterial infection
 Cold sores
 Caused by virus
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Athletes Foot
• Tinea pedis: Athlete’s foot resulting from
a fungal infection.
• Red, itchy, peeling skin.
• Treatment involves an antifungal cream or
pill that will destroy the pathogen.
• Other similar cutaneous fungal infections
include:
– Ringworm
– Sun spots
Cutaneous Fungal Infections
Boils and carbuncles
• Inflammation of hair follicles
and sebaceous glands.
• Typically caused by bacterial
infection; Staphylococcus
aureus.
• Easily treated with an
antibiotic that will
destroy the bacteria
if used properly.
Staph Infections and MRSA
– M = Methicillin, a potent antibiotic
– R = Resistant
– S = Staphylococcus
– A = Aureus
• MRSA = staph infection that is no longer cured
with traditional antibiotics.
• 1950’s: hospital-acquired or NOSOCOMIAL
infection.
– 1.2 million infections/19,000 deaths in 2011.
• Now becoming community-acquired.
– 19000 cMRSA deaths in 2011.
What does MRSA look like?
Skin Homeostatic Imbalances
 Infections and Allergies
 Contact dermatitis
 Exposures cause allergic reaction
 Impetigo
 Caused by bacterial infection
 Psoriasis
 Cause is unknown
 Triggered by trauma, infection, stress
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Impetigo
• Bacterial infection
• Pink, water-filled raised
lesions.
• Usually found around the mouth and
nose.
• HIGHLY contagious.
• Common in young children.
• Easily treated with antibiotics.
Cold sores
• Caused by herpes simplex
(viral) infection.
• Small, fluid-filled blisters that itch and sting.
• Virus follows a cycle
– Outbreaks result from environmental or
emotional stresses.
• OTC medications can shorten infection time
or reduce the size of the lesion.
• No cure.
Categories of Disorders
• Infectious
• Allergic/Environmental:
exposure to agents that lead to
irritation/inflammation.
•
•
•
•
Trauma/Burns
Cancer
Congenital
Genetic
Contact dermatitis
• Itching, redness, swelling of skin.
Progresses to blisters.
• Caused by exposure to chemicals.
• Provokes an allergic response.
• Treated with steroids to reduce
inflammation.
Chemical burn
Poison Ivy
Psoriasis
• Chronic condition;
characterized by red
lesions covered with dry,
silvery scales.
• Cause is unknown, but may be
hereditary.
• Attacks often brought on by
emotional upset, hormonal
changes, and trauma.
Checkpoint Questions
• What 3 types of
pathogens can cause
infections in the skin?
• How do we treat a
herpes simplex
infection?
• What does MRSA
stand for?
• What is the treatment
for typical bacterial
infections?
Checkpoint Questions
• What 3 types of
pathogens can cause
infections in the skin?
• How do we treat a
herpes simplex
infection?
Fungus, Bacteria,
Virus
OTC medicines only.
No cure
• What does MRSA
stand for?
• What is the treatment
for typical bacterial
infections?
Methicillin
Resistant
Staphylococcus
Aureus
Antibiotics
Burns
• A burn is tissue damage and cell
death caused by intense heat or
cold, electricity, UV radiation, or
chemicals.
• Two life-threatening problems
1. Loss of fluids resulting in
dehydration and electrolyte
imbalance.
2. Threat of infection due to loss of
intact barrier.
Rule of Nines
 Way to determine the extent of burns
 Body is divided into 11 areas for quick estimation
 Each area represents about 9% of total body
surface area
 1% is the genital region
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Rule of Nines
Figure 4.11a
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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
 Burn is gray-white or black
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First-degree burn
• Only the epidermis is
damaged.
• Area becomes red and
swollen.
• Temporary discomfort.
• Generally not serious and
heals in two to three days.
• Example: sunburn
Second-degree burn
• Injury to the epidermis and
the upper region of the
dermis.
• Skin is red, painful, and
blistered.
• Regeneration will occur.
• Usually no permanent
scarring.
Third-degree burn
• AKA Full Thickness Burn;
destroys the entire
thickness of the skin.
• Burned area appears
blanched (gray-white) or
blackened.
• Nerve endings are
destroyed.
• Requires skin grafts.
Critical Burns
 Burns are considered critical if
 Over 25% of body has second-degree burns
 Over 10% of the body has third-degree burns
 There are third-degree burns of the face,
hands, or feet
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Categories of Disorders
• Infectious
• Allergic/Environmental
• Trauma/Burns
• Cancer: abnormal mitosis
leading to malignancy.
• Congenital
• Genetic
Skin Cancer
 Cancer—abnormal cell mass
 Classified two ways
 Benign
 Does not spread (encapsulated)
 Malignant
 Spreads
 Metastasized (moves) to other parts of the
body
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Skin cancer
• The most commonly diagnosed cancer
• Many factors can affect a person’s
predisposition to getting skin cancer.
Genetics
Exposure to UV radiation
Frequent skin irritation
Physical trauma
Basal cell carcinoma
• Least malignant/ most common
• Involves cells of st. basale.
• No longer forms keratin;
invades dermis and hypodermis.
• Shiny, dome shaped nodule
that eventually develops a
central ulcer with raised
edge.
Skin Cancer Types
Figure 4.12a
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Squamous cell carcinoma
• Arises from cells in st. spinosum
• Scaly red papule that forms a shallow
ulcer with a firm raised border.
• Grows rapidly and spreads quickly to
lymph nodes.
• Good chance for cure
if caught early.
Skin Cancer Types
Figure 4.12b
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Malignant melanoma
•
•
•
•
Cancer of melanocytes.
5% of skin cancers.
Occurs wherever there is pigment.
Randomly located, but can occur from a
pigmented mole.
• Spreads quickly to lymph nodes and
blood vessels.
• ABCD Rule
Skin Cancer Types
Figure 4.12c
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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
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Categories of Disorders
•
•
•
•
Infectious
Allergic/Environmental
Trauma/Burns
Cancer
• Congenital: malformation of
development occurring during
gestation (pregnancy)
• Genetic
Hemangioma
• Benign swelling of the lining of
blood vessels.
• Dense capillary network that
does not dissolve as fetal
development progresses.
• Many dissolve on own without
intervention by age 10.
• Some can be severely
disfiguring.
CAUTION!
Categories of Disorders
•
•
•
•
•
Infectious
Allergic/Environmental
Trauma/Burns
Cancer
Congenital
• Genetic: mutation of a specific
gene sequence that leads to a
malformation of a protein needed
for normal structure or function.
Ichthyosis
• Malformation of
proteins needed for
normal skin
development.
• Rough, scaly, “fishlike” skin.
• Most dangerous is
Harlequin type.
Epidermolysis bullosa
• Malformation of
collagen and other
connective proteins
that bind/hold the skin
together.
• Results in blistering as
the epidermis pulls
away from the dermis.