2. Seven Functions of theSeven Functions of the
skin…skin…
1.1. Protective coveringProtective covering
2.2. Regulates bodyRegulates body
temperaturetemperature
3.3. Manufactures VitaminManufactures Vitamin
DD
4.4. Sensory FunctionSensory Function
5.5. Temporary storage ofTemporary storage of
fat, glucose, water andfat, glucose, water and
saltssalts
6.6. Excretion of fluidsExcretion of fluids
7.7. Absorbs certain drugsAbsorbs certain drugs
3. Structure of the SkinStructure of the Skin
EpidermisEpidermis
Outermost layerOutermost layer
Dermis- Inner layerDermis- Inner layer
5. Stratum CorneumStratum Corneum
Outer most layer.Outer most layer.
In cells, cytoplasmIn cells, cytoplasm
replaced by Keratin-replaced by Keratin-
making themmaking them
waterproof.waterproof.
Flat and scale-likeFlat and scale-like
cells that flake off.cells that flake off.
First line of defenseFirst line of defense
against surfaceagainst surface
bacteria.bacteria.
Thickest on palms ofThickest on palms of
hands, soles of feet.hands, soles of feet.
6. Stratum GerminativumStratum Germinativum
Innermost epidermalInnermost epidermal
layer.layer.
Reproductive layer- cellsReproductive layer- cells
form and push their wayform and push their way
up, become keratinized,up, become keratinized,
and replace the topand replace the top
layer.layer.
ContainsContains
MELANOCYTES cellsMELANOCYTES cells
that contain a pigment =that contain a pigment =
MELANINMELANIN
7. Melanocytes andMelanocytes and
melaninmelanin
Black, brown, or has a yellow tint-depending on
racial origin.
The more melanin, the darker the skin.
Caucasians don’t have much melanin in their
melanocytes
8. Freckles = patches of melanin
Albinism = no melanin
Sunlight stimulates melanocytes to make
more melanin
Tanning produced by UV rays
Prolonged exposure may lead to skin
cancer
9. PapillaePapillae
Ridges in stratum germinativum that arise
from dermis
Create permanent ridges in fingers, palms,
and soles of feet
These “friction ridges” help with grip
Cause “fingerprints
10. DermisDermis
Thicker inner layer that contains:Thicker inner layer that contains:
Connective tissueConnective tissue □□ Hair folliclesHair follicles
Blood vesselsBlood vessels □□ Oil and sweat glandsOil and sweat glands
Nerve endingsNerve endings □□ Fat cellsFat cells
MusclesMuscles
11.
12. Nerve Receptors inNerve Receptors in
DermisDermis
Sensory nerves –Sensory nerves –
heat, cold, touch,heat, cold, touch,
pain and pressurepain and pressure
Touch receptorsTouch receptors
close to the surfaceclose to the surface
Pressure receptorsPressure receptors
are deeperare deeper
13. Subcutaneous Layer-Subcutaneous Layer-
Adipose tissueAdipose tissue
AdiposeAdipose
Lies under theLies under the
dermis (not reallydermis (not really
part of integumentarypart of integumentary
system).system).
Made up of loose.Made up of loose.
connective tissue.connective tissue.
Contains half of theContains half of the
body’s stored fat.body’s stored fat.
14. Appendages of theAppendages of the
SkinSkinHAIRHAIR
Almost everywhere on theAlmost everywhere on the
bodybody
Length, thickness, type andLength, thickness, type and
color varies.color varies.
Outer layer = CORTEXOuter layer = CORTEX
Inner layer = MEDULLAInner layer = MEDULLA
Part under the skin = ROOTPart under the skin = ROOT
Part outside the skin = SHAFTPart outside the skin = SHAFT
FOLLICLE = pocket inFOLLICLE = pocket in
epidermis, hair inside.epidermis, hair inside.
PAPILLA = tuft of tissue inPAPILLA = tuft of tissue in
root, contains, capillaries.root, contains, capillaries.
15. Arrector Pili MuscleArrector Pili Muscle
APM = smooth muscleAPM = smooth muscle
attached to follicle. It isattached to follicle. It is
innervated by the autonomicinnervated by the autonomic
nervous system.nervous system.
function is to providefunction is to provide
insulation: air becomes trappedinsulation: air becomes trapped
between the erect hairs,between the erect hairs,
helping retain heathelping retain heat
NailsNails
Nail is formed in the nail bed orNail is formed in the nail bed or
MATRIX.MATRIX.
Epidermal cells fused togetherEpidermal cells fused together
and fill with keratin.and fill with keratin.
16. Sweat GlandsSweat Glands
SUDORIFEROUS GLANDS.SUDORIFEROUS GLANDS.
Perspiration is 99% water.Perspiration is 99% water.
Location is over the entire skinLocation is over the entire skin
surface.surface.
Pores- Large numbers under thePores- Large numbers under the
arms, palms of hands, soles of feetarms, palms of hands, soles of feet
and forehead.and forehead.
Duct extends to form a pore in theDuct extends to form a pore in the
skin, perspiration excreted throughskin, perspiration excreted through
the pores.the pores.
May be activated by heat, pain, feverMay be activated by heat, pain, fever
and nervousness.and nervousness.
Average fluid loss in 500 ml per day.Average fluid loss in 500 ml per day.
It's the bacteria that live
on your skin that mix with
the sweat and give it a
stinky smell. And when
you reach puberty,
special hormones affect
the glands in your armpits
— these glands make
sweat that can really
smell
17. Sebaceous GlandsSebaceous Glands
Secret Oil (SEBUM)Secret Oil (SEBUM)
that protects andthat protects and
lubricates the skin.lubricates the skin.
18. Skin andSkin and
MicroorganismsMicroorganisms
Intact skin = best protection againstIntact skin = best protection against
pathogens, toxins and water loss.pathogens, toxins and water loss.
Skin generally too dry for microbial growth –Skin generally too dry for microbial growth –
they do grow in moist areas.they do grow in moist areas.
Most skin bacteria associated with hair folliclesMost skin bacteria associated with hair follicles
or sweat glands.or sweat glands.
Underarm perspiration odor caused byUnderarm perspiration odor caused by
bacteria and perspiration.bacteria and perspiration.
19. Best way to prevent spread of disease is
hand washing
Regulation of body temperature
Manufactures vitamin D
Sensory perception
Storage
Sun screen
Absorption