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THE THE INTEGUMENTARINTEGUMENTAR
Y SYSTEMY SYSTEM
I. IntroductionA.Basics
1.Consists of skin, hair, nails, and cutaneous glands.
2.Largest organ of body• 15-20 sq. ft• 9 lbs• 0.5-4.00 mm thick
B. Layers1.Epidermis
• Epithelial t.2.Dermis
• Connective t.3.Hypodermis (subcutaneous t.)
• Loose connective t. (fat)• Not part of the skin• Anchors the skin to bone and muscle
tissue
C. Functions1. protection
2. Vitamin D production
3. Sensation
4. Thermoregulation
5. Excretion (small amount)
II. EpidermisA.A.GeneralGeneral
1.Keratinized, stratified, squamous epithelium
2.New epidermis every 35-45 days
II. Epidermis
A.A.GeneralGeneral3.Callus – gross
thickening due to friction
4. Blister – acute trauma leads to separation of dermis and epidermis
II.EpidermisB. Cell types
II. EpidermisB. Cell typesB. Cell types
1. Keratinocytesa.Produce fibrous protein keratin
• tough, water repellant protein
• protects the skin and the underlying tissues from heat, microbes, abrasion and chemicals
b.Produced in deepest layer
II.EpidermisB. Cell types
B. Cell types
•Pigment is phagocytized by keratinocytes
•Pigment granules protect keratinocytes from UV radiation
2. Melanocytes
•Produce pigment melanin
Normal skin color determinants Melanin
Yellow, brown or black pigments Carotene
Orange-yellow pigment from some vegetables
Hemoglobin
Red coloring from blood cells in dermis capillaries
Oxygen content determines the extent of red coloring
B. Cell typesB. Cell types3. Merkel’s cells
•Associated w/nerve cell endings – touch reception in fingertips
4. Langerhans’ cells• Macrophage-like• Defend against
microorganisms• Found in Stratum Spinosum
II.Epidermis
C. Layers
Hint to remember the layers:
•Can Corneum•Little Lucidum•GiRls GRanulosum•SPeak SPinosum•GERMan/ GERMinativum•British or Basale
Can Little Girls Speak German or British
II. EpidermisC. Layers
1.Stratum Basalis • AKA:Stratum
Germinativum
• Single layer of cuboidal cells• Mitotic•10-25% melanocytes deposited here.
C. Layers1.Stratum
Basalis • Receive nutrients by diffusion from dermis• Composed of columnar keratinocytes melanocytes & Merkel’s cells or disks (light touch receptors)
C. Layers 2. Stratum
Spinosum • Called the “Spiny Layer” (8-10 layers thick)• Less mitotic ~ less nutrition received.• Cells are many sided keratinocytes often called “Prickle Cells”
•Scattered among keratinocytes are Langerhans’ cells (immunity cells)
C. Layers 2. Stratum
Spinosum
Note: The Stratum Basalis and Stratum Spinosum•contain the only epidermal cells that receive adequate nourishment by way of diffusion.
•As the daughter cells are pushed upward, away from the source of nutrition, they gradually die and their soft protoplasm becomes keratinized (hard).
C. Layers
3.Stratum Granulosum
• Granular layer• Keratinization
begins • Cells begin to
die• Thin layer 3-5
cell layers
C. Layers
• Clear layer • Found in thick
skin only as palms and soles of feet
• Contain Keratin fibrils
• Cells begin to degenerate
4. Stratum Lucidum
C. Layers5. Stratum
Corneum• Horny Layer • 20-30 cell = ¾of
thickness. • Prevents water
loss due to lipids in surrounding cells, adds strength due to keratinization & exfoliaiton prevents abrasion of cells.
C. Layers
5.StratumCorneum• Consists of dead
flat (stratified squamous) keratinized cells being sloughed off
• Forms from the embryological ectoderm germ layer.
II. Epidermis
III. Dermis
III. Dermis aka: hide
A.General1.Strong,
flexible, connective tissue
2.Thickness: 0.6 – 3 mm
III. DermisA. Has collagen,
elastic & reticular fibers
B. Develops fromthe mesoderm ofthe embryological
germ layer.
A. GeneralContains• Blood vessels• Nerves• Hair follicles• Sebaceous Oil glands• Sudiferous Sweat
glands• Nail roots• Skin Appendages
A. GeneralEpidermis projects
intodermis to form
dermalPapillae.Touch ReceptorsHair follicles
B. 2 Layers: Papillary & Reticular
III. Dermis
B. Layers1.Papillary
Layer a.Closest to
epidermsb. Made of areolar, loose
con. t.c. Has Dermal Papillae
• Finger-like projects that indent into the epidermis
• Contain Capillaries
pain receptors Meisner corpuscles:
sensitive to light touch, discriminative touch, & low vibrations. Allows you to gather information about objects shape, texture, & density, so your brain can identify the object
Finger prints
c. Has Dermal Papillae
a.Deepest layerb.Comprises 4/5 of
dermisc.Made of dense
irregular connective tissue
B. Layers 2. Reticular
layer
III. Dermis
d.Rich in blood vessels and nerve
e.Pacinian corpuscles – (egg shaped) sensitive to deep tactile pressure & high frequency vibration. Adapt rapidly. act as intestinal & joint proprioceptors & enable you to detect the object due to its weight
B. Layers
2. Reticular layer
III. Dermis
d.Ruffini’s corpuscle senses heat found skin & mouth
e.Krause’s End Bulb senses cold found in mucus membrane of mouth
B. Layers
2. Reticular layer
III. Dermis
f. Tension lines or cleavage – separation of collagen bundles
g. Flexure line – folding of dermis at joints of wrists, palms, fingers toes
B. Layers
2. Reticular layer
III. Dermis
IV. Hypodermis aka superficial fascia
1.Areolar and adipose tissue
2.Anchors skin to organs
3.Insulates, absorbs shock, stores fat, ½ of body’s stored fat is here.
True or False?
1. The dermis is the superficial layer of the skin.
2. The skin helps regulate body temperature.
3. The epidermis has three layers.
4. The hypodermis is above the dermis.
5. The skin protects against UV radiation.
Functions of Skin?• The four main functions of the integumentary
system are: (Waste Excretion, Movement, Thermoregulation, Protection, Sensation, Immunity)
1. Which function acts as a barrier against chemical, mechanical, and microbial damage?
2. Which function acts to maintain constant internal temperature?
3. Which function acts to receive stimuli from the environment?
4. Which function acts to release sweat contains organic chemicals, salts, and urea?
V. Skin AppendagesA.General(4 embryonic categories: hair,
nails, nerves, & glands)
1.Organs that develop from the embryonic epidermis
2. Also called epidermal derivatives
V. Skin Appendages3.Includesa.Hairb.Sweat ,
sudoriferous, glands
c.Sebaceous, oil, glands
d.Finger nailse.Tooth enamel
V. Skin AppendagesB. Hair
1.Is fused keratinized cells
2.Protects against • Scalp
injury• Sun• Heat loss
3. Hair• Hair is a slender filament of mostly dead keratinized epithelial cells that grow from a follicle
• Is a derative of the modified stratum corneum
• The hair consists of the medulla, a core of loose cells and air spaces, surrounded by a cortex, which is densely packed keratinized cells.
• The cortex is covered by the cuticle.
3. Hair•The bulb is a swelling at the base where the hair originates; the root is the remainder of the hair within the follicle; and the shaft is the portion of the hair above the skin surface.
•Erector pili muscles are smooth muscle
V. Skin AppendagesB. Hair
1.Is fused keratinized cells
2.Protects against • Scalp
injury• Sun• Heat loss
B. Hair3. Structure
a.Shaft• Above
surface• Shape
determines curliness – Round =
straight– Oval =
wavy– Flat = kinky
Note: The
root and shaft are made of 3 tubes
Note: 3 tubesNote: 3 tubes• cuticle: outer tube
1 layer of heavily keratinized cells.
• cortex: middle tube several layers of cells w/
pigments in dark hair and air bubbles in white hair.
• medulla: inner tube made of 2 -3 rows of cells with
pigments and air spaces.
B. Hair Follicle• Hair Bulb Matrix
produces hair • Inner epidermal
sheath made of epithelial tissue
• Outer dermal sheath made of dermal connective tissue.
• Arrector pili muscle – goose bumps
V. Skin AppendagesB.Hair4. Split ends – cuticle wears away5. Color results from melanin
(black, brown, yellow)6. Hair growth/loss – depends on
genes, stress, illness, malnutrition, hormone levels, some hair styles (ie tight braids), excessive combing, & styling (w/use of hair chemicals) & Excessive exercise
V. Skin AppendagesB.Hair: Kinds of hairLanugo – fine downy hair present in fetus and
replaced at birth.
Vellus hair: fine pale body hair of women and children. Approx 2/3 of hair in ♀ and 1/10 in ♂ and all hair in children, except eyebrows, eyelashes and scalp hair.
Terminal hair: coarse, pigmented male body hair. Forms eyebrows, eyelashes, scalp and pubic, axillary, and facial hair after puberty.
Cycle of Hair Growth
• Newly formed hair cells move up the follicle as newer cells form beneath.
• As the cells dry out & fill w/keratin the hair cells begin to harden & die.
V. Skin AppendagesC.Nails
1.Scale-like epidermal derivatives
2.Pink due to capillaries in dermis
C. Nails3. Nail plate isheavily karantinized4. Nail body ormatrix is the nail
itself where mitosis occurs.
5. Nail root is responsible for growth
C. Nails
C. NailsStratum basale extends beneath the nail bed
The nail contains a free edge, a body, & nail root.
Eponchium (cuticle) is the proximal nail fold that projects onto the nail body.
Lunula is the half moon shaped portion of the nail that lacks pigmentation.
Subungal Hematoma: blood clot beneath the nail.
V. Skin AppendagesD. Sudoriferous Glands
1. Sweat glands2. Two types: Eccrine or Merocrine &
Apocrine3. Both sectete sweat, which
evaporates & cools the body.4. Merocrine/Eccrine – most common
type; most numerous in the palms of the hands & soles of the feet. Not found in lips, nipples and parts of external genitalia. Open by way of a duct to pore in the skin.
V. Skin AppendagesD.Sudoriferous Glands : Sweat
glands Apocrine – are most numerous in the axillary & the genital regions & around the anus. The duct empties into a nearby hair follicle. They become active @ puberty as a result of sex hormones. 6. Mammary Glands are
considered modified apocrine sweat glands.
V. Composition & Function of Sweat Glands Made mostly of water, some metabolic
wastes & fatty acids & proteins (apocrine)
Function
Helps dissipate excess heat
Excretes waste products
Acidic nature inhibits bacteria growth
Odor is from associated bacteria
D. Sudoriferous Glands
4.Function• Assists in
maintaining normal body temp.
D. Sudoriferous Glands5. specialized
sudoriferous glands• Mammary
glands• Ceruminous
glands
Cerum = earwax
D. Sebaceous Glands Sebaceous glands
Produce oil
Lubricant for skin
Kills bacteria
Most with ducts that empty into hair follicles
Glands are activated at puberty
V. Skin AppendagesE.Ceruminous
Glands1. Produce Sebum
• Oil• Prevents skin
from drying out• Protects against
bacteria2. Exocrine
Fill in the blanks with: hypodermis, keratinocytes, sweat, or papillary.
1. Eccrine is a type of _______________ gland.
2. _______________ produce keratin.
3. Adipose tissue is found in the _______________.
4. The _______________ of the dermis forms fingerprints.
V. Skin Appendages
E.Tooth Enamel1. the hard outer
layer of the tooth.
VI. Skin Color
A.Melanin1.Made by
• melanocytes• transferred to
keratinocytes2.Yellow to orange to brown3.Racial differences result of
kind and amount of melanin
A. Melanin4.Builds up with sun
exposure protects •Over exposure
alters DNA cancer and/or leathery skin
Not enough UV to break down of folic acid (vit. B) anemia or neural tube defects
A. Melanin4.Builds up with sun
exposure protects •Under exposure
MS Rickets Osteoporosis
B. Carotene
1.Yellow to orange
2.Found mainly in Corneum Layer, soles, palms
C. Hemoglobin1.In red blood
cells in capillaries
2.Gives pinkish hue to Caucasian skinNote: Caucasian’s have less melanin
VII. OtherA. Regulation of Body Temp.
1.Negative feedback system2.Excessive Heat
• Vessels dilate• Sweat evaporates from skin
3.Prevent heat loss• Vessels constrict• Arrector pili muscles cause
hair to stand on end
VII. Other Infections
Athletes foot
Caused by fungal infection
Boils and carbuncles
Caused by bacterial infection
Cold sores
Caused by virus
VII. Other Infections and allergies
Contact dermatitis
Exposures cause allergic reaction
Impetigo
Caused by bacterial infection
Psoriasis
Cause is unknown
Triggered by trauma, infection, stress
VII. Other Psoriasis
VII. OtherB. Aging
1.Blood flow to skin reduced• Thins skin/ more
easily damaged• Repair is slower
2.Sagging results from• Elastic fibers reduce
in number & diameter
• Loss of subcutaneous tissue
VII. OtherB.Aging
3.Age Spots• Localized areas
of increased # of melanocytes
4.Gray hair• Decrease or lack
of melanin production
VII. OtherVII. OtherC.C. Skin CancerSkin Cancer
1.The most common type of cancer
2. It occurs more often in people with light colored skin who have had a high exposure to sunlight.
Skin CancerSkin Cancer Cancer – abnormal cell mass
Suffix “-oma” means tumor
Two types
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 Moles
VII. OtherC. Skin Cancer
3. Signs of skin cancer a. growth or a sore that
won't healb. a small lump.
• smooth, shiny and waxy
• or it can be red or reddish brown.
c. a flat red spot that is rough or scaly.
Skin cancers
VII. OtherC.Skin CancerMost common type
yet least malignant:
a.a.Basal CellBasal Cell CarcinomasCarcinomas
b.Caused by exposure to the sun
Basal Cell Carcinoma
VII. OtherC.Skin Cancer
3.Frequent type:
b.b.Squamous Cell Squamous Cell CarcinomaCarcinoma
Metastasizes to lymph Metastasizes to lymph nodesnodesSun exposureLips of smokersEarly removal allows
forgood chance of survival
Squamous Cell Carcinoma
VII. OtherC.Skin Cancer
3.Most deadly type:
c.c.MelanomaMelanoma• Most malignant• Caused by sun
exposure• Metastasizes
rapidly to lymph and blood vessels
Melanoma
IV. OtherIV. OtherC.C.Skin CancerSkin Cancer
4.4. ABCD Rule ABCD Rule to distinguish a to distinguish a normal mole from a melanomanormal mole from a melanoma• AA ... Asymmetrical halves the
different halves of the mole don't look like each other
• BB ... Border irregularity the edges of the mole are indented or notched.
• CC ... Color variation different colors in pigmented area
• DD ... Diameter greater than the size of a pencil eraser tip or 6mm
VII. Other Burns
Tissue damage and cell death caused by heat, electricity, UV radiation, or chemicals
Associated dangers
Dehydration
Electrolyte imbalance
Circulatory shock
Severity of a BurnSeverity of a Burn
• Severity of a thermal wound correlates directly with:– Temperature– Concentration– Amount of heat energy
possessed by the object or substance
– Duration of exposure
Burn severity depends on:
1. Depth of burn
2. Extent of burn
3. Critical areas involved• Face, upper airway,
hands, feet, genitalia
4. Preexisting medical conditions
5. Patient younger than 5 or older than 55
VII. OtherVII. OtherD.D. BurnsBurns
1.1. 11stst Degree, Mild, Degree, Mild, SuperficialSuperficial• Minor epithelial damage • Red, tender• DryDry • No blisters • Mild Edema
Mild Burn
VII. BurnsVII. Burns22ndnd Degree, Moderate, Degree, Moderate,
Partial ThicknessPartial Thickness• Damage to epidermis and
superficial (papillary) dermis• Pink, exquisitely tender• MoistMoist• Blisters • Heals in 2-3 wks w/oscarring.
Partial Thickness Burns
Partial Thickness Burns
VII. BurnsVII. BurnsD.D.33rdrd Degree, Severe, Full- Degree, Severe, Full-
thicknessthickness• Involves all 3 skin layers• Color variable: white, waxy,
red, brown, red (scalds)• Destroys elasticity• Dry• Painless• Does not heal
Third Degree Burn
Rule of 9’s
– Used to estimate surface area affected by the burn.
• Divide body into 9% sections
D. BurnsD. Burns 3. Rule of 9’s3. Rule of 9’s
• Torso: 18% • Leg: 18% • Head: 9% • Arm: 9% • Genitalia:
1% • Palm: 1%
Critical BurnsCritical 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
VII. VII. HOMEOSTASIS & HOMEOSTASIS & TISSUESTISSUESA. Inflammatory Response A. Inflammatory Response
1.Inflammation produces swelling, redness, heat, tenderness, and a loss of function at the inflamed site.
VII. VII. HOMEOSTASIS & HOMEOSTASIS & TISSUESTISSUESA. Inflammatory Response A. Inflammatory Response
An infection infection is an inflammation produced by an invading organism, such as a bacterium.
BB. Inflammatory Response . Inflammatory Response 2.2. Sequence of EventsSequence of Events
homeostasis disturbed mast cells release chemicals blood flow and permeability increases clot formation isolates area phagocytes remove debris and microorganisms homeostasis returns
Injury and Repair• The skin can regenerate after injury.
• After injury there are four stages of healing:1. After injury bleeding usually occurs into the site.
2. Clot or scab forms at the surface of the epidermis.
3. Granulation occurs and the clot dissolves.
4. Scar tissue forms and the extent of scarring depends on the degree of the injury.
2 types of Tissue Repair2 types of Tissue Repair
Slide 3.69Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
1. Regeneration Replacement of destroyed tissue by the
same kind of cells
2. Fibrosis Repair by dense fibrous connective tissue
(scar tissue)
Determination method for repair type: Type of tissue damaged
Severity of the injury
Events in Tissue RepairEvents in Tissue Repair
Slide 3.70Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Capillaries become very permeable Introduce clotting proteins
Wall off injured area
Formation of granulation tissue
Regeneration of surface epithelium
Regeneration of TissuesRegeneration of Tissues
Slide 3.71Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Tissues that regenerate easily Epithelial tissue
Fibrous connective tissue and bone
Tissues that regenerate poorly Skeletal muscle
Tissues that are replaced largely with scar tissue Cardiac muscle
Nervous tissue within the brain and spinal cord
Developmental Aspects of TissueDevelopmental Aspects of Tissue
Slide 3.72Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Epithelial tissue arises from all three primary germ layers
Muscle and connective tissue arise from the mesoderm
Nervous tissue arises from the ectoderm
With old age there is a decrease in mass and viabililty in most tissues
THE ENDTHE END
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