Skin is called the cutaneous or integument Skin has two regions The epidermis The dermis

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