Integumentary System

Integumentary System

Body's largest organ system and first line of defense against pathogens chemicals and pollutants

Protective Barrier

Main function of the integumentary system protects against microorganisms chemicals and water loss

Thermoregulation

Regulation of body temperature through sweat glands and blood flow

Vitamin D Production

UV exposure converts skin proteins into vitamin D

Concentration (Permeability Factor)

Higher concentration increases likelihood of absorption through skin

Duration of Contact (Permeability Factor)

Longer exposure increases absorption

Molecule Size (Permeability Factor)

Smaller molecules penetrate skin more easily

Water-Soluble

Dissolves in water and is repelled by lipid bilayers

Lipid-Soluble

Dissolves in lipids and passes through lipid bilayers

Normal Core Temperature

36.5-37.5°C (97.7-99.5°F)

Conduction

Heat transfer through direct contact

Convection

Heat transfer to surrounding air or water

Evaporation

Heat loss through vaporization of sweat

Radiation

Loss of heat through infrared energy waves

Skin (Integument)

Organ that prevents water heat and molecule loss while protecting against pathogens

Hypodermis

Subcutaneous layer of loose connective and adipose tissue

Subcutaneous Layer

Another name for hypodermis

Adipose Tissue

Fat tissue that insulates and protects

Epidermis

Outermost skin layer made of stratified squamous epithelium

Basement Membrane

Structure separating epidermis from dermis

Stratum Corneum

Outermost epidermal layer of dead keratinized cells

Dandruff

Excessive shedding of the stratum corneum

Stratum Lucidum

Transparent layer found only in thick skin of palms and soles

Stratum Granulosum

Layer containing keratin granules where cells begin to die

Stratum Spinosum

Layer where cells move upward toward skin surface

Stratum Basale

Deepest epidermal layer containing stem cells

Stratum Germinativum

Another name for stratum basale

Stem Cells (Skin)

Cells that continuously produce new epidermal cells

Dermis

Connective tissue layer beneath epidermis

Papillary Layer

Upper dermal layer containing dermal papillae

Dermal Papillae

Projections that increase friction and form fingerprints

Reticular Layer

Deep dermal layer rich in collagen and elastic fibers

Collagen

Protein providing strength and resistance to stretching

Elastic Fibers

Fibers providing flexibility and elasticity

Melanin

Pigment that determines skin hair and eye color and absorbs UV radiation

Melanocytes

Cells in stratum basale that produce melanin

Melasma

Dark facial pigmentation commonly occurring during pregnancy

Genetics (Melanin)

Determines amount and type of melanin produced

UV Exposure

Stimulates melanin production causing tanning

Keratin

Tough waterproof protein found in skin hair and nails

Keratinization

Process of adding keratin as epidermal cells move upward

Keratinocytes

Cells that produce keratin

Impetigo

Highly contagious bacterial skin infection with yellow crusted sores

Urticaria

Hives characterized by itchy raised welts

Psoriasis

Chronic autoimmune disease causing scaly red or silver patches

Vitiligo

Loss of skin pigment due to melanocyte death or reduced melanin production

Albinism

Genetic disorder causing little or no melanin production

Epidermolysis Bullosa

Rare genetic disorder causing fragile blistering skin

Staphylococcal Scalded Skin Syndrome

Serious bacterial infection causing skin blistering and peeling

Abrasion

Superficial scrape involving only the epidermis

Avulsion

Wound where skin is torn away exposing deeper tissues

Laceration

Deep cut or tear in the skin

Puncture

Wound caused by a pointed object creating a hole

Burn

Tissue damage causing cell death dehydration and infection risk

First-Degree Burn

Superficial burn affecting only epidermis

Second-Degree Burn

Partial-thickness burn affecting epidermis and dermis

Third-Degree Burn

Full-thickness burn affecting epidermis dermis and deeper tissues

Rule of Nines

Method for estimating percentage of body surface burned

Hemostasis

First stage of wound healing where clotting stops bleeding

Inflammatory Phase

Stage where white blood cells remove pathogens and debris

Proliferative Phase

Stage where new tissue forms and covers wound

Maturation Phase

Final healing phase where collagen reorganizes

Keloid Scar

Excessive scar extending beyond original wound borders

Hypertrophic Scar

Raised scar that remains within wound boundaries

Contracture Scar

Tight scar common after burns that may restrict movement

Basal Cell Carcinoma

Most common skin cancer rarely metastasizes

Squamous Cell Carcinoma

Skin cancer more likely to invade deeper tissues and spread

Melanoma

Cancer arising from melanocytes with high metastatic potential

ABCDE Rule

Tool used to identify possible melanoma

Asymmetry

One half of lesion does not match the other

Border

Irregular uneven border of a mole

Color

Variation of colors within a lesion

Diameter

Change in size of a lesion

Evolution

Changes in size shape or color over time

Accessory Structures

Nerves vessels glands hair follicles and nails associated with skin

Hair

Keratinized structure found on most body surfaces

Hair Follicle

Tubular structure surrounding root of hair

Inner Epithelial Root Sheath

Part of follicle that forms hair

External Epithelial Root Sheath

Part supplying nourishment to hair bulb

Arrector Pili

Smooth muscle that raises hair causing goosebumps

Goosebumps

Raised skin caused by arrector pili contraction

Hair Growth

Occurs as new cells push older cells upward

Hair Color

Determined by amount and type of melanin

Round Hair Shaft

Produces straight hair

Oval Hair Shaft

Produces wavy hair

Flat Hair Shaft

Produces curly hair

Nails

Modified highly keratinized epidermal structures

Eponychium

Cuticle covering proximal nail fold

Nail Bed

Stratum basale beneath nail body producing new nail cells

Nail Body

Visible portion of the nail

Free Edge

Distal white portion of nail

Nail Root

Proximal part of nail embedded in skin

Lunula

White half-moon region at base of nail

Sudoriferous Glands

Sweat glands involved in thermoregulation and protection

Eccrine Sweat Glands

Sweat glands found throughout the body for thermoregulation

Eccrine Secretions

Water salts urea ammonia uric acid and lactic acid

Apocrine Sweat Glands

Sweat glands associated with hair follicles in axillary and genital regions

Apocrine Secretions

Sweat containing proteins and fatty acids

Sebaceous Glands

Oil glands that secrete sebum

Sebum

Oily secretion that softens skin and inhibits bacterial growth