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Skin is called the cutaneous or integument
Skin has two regions
The epidermisThe dermis
EpidermisThe outer thinner region of the skin
Made up of stratified squamous epithelium
Divided into the stratum basale and the stratum corneum
EpidermisStratum basale- just superior of the dermis
Langerhans cells- macrophages found deep in the epidermis that phagocytize microbes and simulate the immune system
Melanocytes- specialized cells in the deeper epidermis that produce melanin, responsible for skin color
EpidermisStratum corneum- the uppermost layer of
the skin
Keratin- a fibrous, waterproof cell
Mechanical barrier against microbe invasion
Epidermis
DermisA deeper and thicker region
Composed of dense irregular connective tissue
Dermal papillae causes ridges resulting in fingerprints
Contains collagenous and elastic fibers
Dermis
Collagenous fibers prevent skin from being torn and great resistance from over stretching
Elastic fibers allow movement but maintain normal skin tension
A deeper and thiker region
Dermis
Dermis
Decubitus ulcers- sore caused by a lacked of blood flow in a particular area that is restricted
Hypodermis
Subcutaneous tissue Lies below the dermis Composed of loose connective tissue
including adipose
Hair Found everywhere on the body except:
PalmsSolesLipsNipples
Hirsutism: excessive body and facial hair
Alopecia- lack of hair or baldness
Hair follicles:Are formed from epidermal cellsBut are located in the dermis
Root- portion of the hair found in the follicle
Shaft- portion of the hair found above the skin
Hair follicles:Are formed from epidermal cellsBut are located in the dermis
Root- portion of the hair found in the follicle
Shaft- portion of the hair found above the skin
Hair follicles:
Nails:From special epithelial cells at the base of
the nail called the nail rootNail body is the visible portion of the nailLunula is the whitish half moon shaped base
Glands: specialized cells that produce and secrete a substance into ducts
Sweat gland:Present in all skinTubularGlands are active under stress
Sweat gland:Apocrine glandOpen into hair
follicles In anal, groin, and
armpitsBegins secreting at
puberty
Sweat gland:Eccrine glandsOpen to surface of
the skinActive when a
person is hotContains water,
salts, urea, and waste
Sebaceous glandsAssociate with a hair follicleSecrete sebum : an oil substanceLubricates and waterproofs
Acne vulgarisMost common Inflammation of the sebaceous glands
Mammary glandsLocated in breastProduces milk
Athlete’s Foot: fungal infection of the toes and sole
Impetigo: highly contagious bacterial infection that results in pustules
Psoriasis: chronic condition, the skin is reddish pink patches covered by silver scales
Eczema: an inflammation of the skin caused by sensitivity
Cyanosis: condition in which the skin has a bluish tint caused by insufficient oxygen in the blood
Jaundice: yellowing of the skin caused by an accumulation of bilirubin
Albinism: loss of pigment in the skin creating patches of white skin
Freckles: melanin concentrated in local areas
Dandruff: flaking of the scalp due to accelerated keratinization
Uricaria: hive caused by an allergic reaction
Nonmelanoma: Basal cell carcinoma Most common Caused from UV exposure Signs are tumors, open sores, reddish
patches, smooth growths, shiny bumps or pale marks
Nonmelanoma: Basal cell carcinoma
Nonmelanoma: Squamous cell carcinoma
More like to spread Signs bleeding warts and scabs
Nonmelanoma: Squamous cell carcinoma
Squamous cell carcinoma
Basal cell
Melanoma: Starts as a mole Skin around mole turns colors Occurs mostly in fair skinned
individuals with a history of sunburns as a child
Melanoma:
Moles: due to an overgrowth of melanocyte
Warts: caused by a virus
BurnsCaused by Chemicals, Radiation, and
HeatExtent of a burn is determined by the
“Rule of Nine”Classified by depth of the burn and the
extent of the burn
First Degree BurnsOnly the epidermisReddness and pain,
no blistersSubside in 2-3 days
Second Degree BurnsOnly the epidermis and dermisReddness , pain, and blistersSubside in 10-14 days
Third Degree BurnsDestroys entire thickness of the skinLeathery surface of brown, black, tan,
white or redDestroyed nerves, blood vessels, glands,
and follicles
Third Degree Burns
Fourth Degree BurnsDestroyed down to boneLimited chance of survival
Major concerns with burns:Fluid lossHeat lossBacterial infections
AutograftingGraft taken from another part of the
patients bodyPreferred method
HeterograftingGraft taken from another person
Skin Grafts
EpidermisMaintain thickness but cell turnover
decreasesSkin is looser
DermisThinnerFlattenedCollagenous fibers coarser, thicker, far
apartUpper layer lostDecrease in melanocytes
HypodermisAdipose tissue decreases
Wrinkles caused by:Loose epidermisFibers are fewer and disorganizedLess padding
Functions of the skinProtective functionHelps regulate water lossProduces vitamin Regulates body temperatureGathers sensory information
Hypothermia: Body temperature below normal
Characterized byUncontrolled shivering Incoherent speech Lack of coordinationProgresses to
pulse rate slowshallucinationsshallow breathingrigidity
Hyperthermia: Body temperature above normal
Heat stroke- body temperature above 110 degrees F w/o sweating
Fever