cs 9-12 forensic anatomy. skin hair nails associated structures (vessels, nerves, glands)

INTEGUMENTARY

SYSTEM

CS 9-12 Forensic Anatomy

INTEGUMENTARY SYSTEM

· Skin

· Hair

· Nails

· Associated Structures (vessels, nerves, glands)

FUNCTIONS OF THE INTEGUMENTARY SYSTEM· Protection

· Block out pathogens & debris

· Keeps body from drying out

· Nails protect tips of fingers & toes

· Body Temperature Regulation

· Release excess heat, keep in heat

· Hair prevents heat loss from head

· Excretion

· Sweat contains waste products – urea, salt, etc.

FUNCTIONS OF THE INTEGUMENTARY SYSTEM· Information Gathering

· Contain sensory receptors (nerves)

· Connects the outside environment to the nervous system

· Vitamin D Production

· Vitamin D needed to absorb calcium and phosphorous from the small intestine

· Sunlight needed for chemical reaction to produce Vitamin D

STRUCTURE OF THE SKIN

STRUCTURE OF THE SKIN

· Main layers –

· Epidermis

· Dermis

· Hypodermis – not always considered part of skin

EPIDERMIS

Outer layer of the skin2 layers of epidermis

Out layer of the epidermisLayer you seeMade up of dead skin cells

Inner layer of the epidermisMade up of live cellsStem cellsKeratin

protein, hair and nails are made of keratin

Every 4-6 weeks a new layer of skins replaces the dead cells

EPIDERMIS

Contains melanocytesCells that produce

melanin Melanin protects

skin by absorbing UV rays

Responsible for skin color More melanin

produced, darker skin color

DERMIS

Lies beneath the epidermis

ContainsCollagenBlood vesselsNerve endingsGlandsSensory receptorsSmooth musclesHair follicles

DERMIS

Structures here interact with other system to maintain homeostasis, body temperatureCold- blood vessels contract, bring blood closer

to the bodies core, prevents heat from escapingWarm-blood vessels widen, releasing heat from

the body’s coreSweat glands- produce perspiration (sweat)

Sebaceous glands- produce sebum (oil) to keep skin flexible and waterproof, acidic and kills bacteria on the skin’s surface

HAIR Keratin

makes nails and hairHorns, scales, feathers, quills, etc.

Protects head from heat loss & UV rays In nostrils, ears, around eyes

Protects particles from entering the body Hair follicles – pockets of epidermal cells

that extend into the dermis where hair originatesClose to sebaceous glands to keep hair soft

and flexible

NAILS

Grow from the nail root Protects the tips of fingers and toes Grow on average of 3mm/month Fingernails grow ~3X faster than

toenails

SKIN CANCERSkin cancer is the most common type of cancer

2 out of 5 cancers are skin cancers

Skin Cancer· Cancer – uncontrolled cell growth· Caused by damage to the DNA usually

through chemicals or radiation· Two types

· Benign· Does not spread (encapsulated)

· Malignant· Metastasized (moves) to other parts of

the body

Skin Cancer Types

Basal cell carcinoma· Not malignant · Most common type·cannot produce keratin·Boundary lost between dermis and epidermis· Seldom metastasizes – treated surgically or by radiation

· Pale marks· Reddish patches· Round, smooth growth with raised edge· Shiny bumps· Sores that don’t heal

BASAL CELL CARCINOMA

BASAL CELL CARCINOMA

Skin Cancer Types· Squamous cell carcinoma

· 2nd most common skin cancer· Highest risk – fair skin, light hair, blue/green

eyes· Metastasizes to lymph nodes if left untreated

· 1500-2000 deaths in US per year· Early removal allows a good chance of cure· Signs are same as basal cell carcinoma

SQUAMOUS CELL CARCINOMA

MELANOMAS

Malignant Melanoma tends to occur in younger ages (as well as older people)

It is due to repetitive intense exposures (aka: sunburns)

This is the most serious form of skin cancer and MUST be caught early to be treated successfully!

ABCD Rule· A = Asymmetry

· Two sides of pigmented mole do not match· B = Border irregularity

· Borders of mole are not smooth· C = Color

· Different colors in pigmented area· D = Diameter

· Spot is larger then 6 mm in diameter (pencil eraser)

· Mole starts growing/changing in size

Malignant Melanoma

MELANOMAS

MELANOMAS

PREVENTION Wear sunscreen whenever outside or cover up avoid midday sun between 10-2 and beware of

reflected light higher altitudes - every 1000 ft above sea level,

radiation increases 4-5 % Be cautious about tanning beds Medications - tetracycline (antibiotics), Retin A,

birth control, antidepressants, diuretics, and anti-inflammatories cause

photosensitivity avoid sunburns examine skin regularly - remember ABCD

rule – have full body check by dermatologist once a year

OTHER INTEGUMENTARY SYSTEM DISORDERS

· Ezcema· Exposure to allergen/irritant (ie. poison ivy) cause allergic reaction

· inflammation, red, itchy skin· not contagious· over the counter meds; sometimes Rx· Prevention by avoiding allergen/irritant

· Blisters· Epidermal cell injury or separation of epidermis from dermis

· Warts· Contagious· Remove by freezing, drying, laser therapy,

chemicals· Boils

· infection that infects hair follicles· Large, inflamed, pus-filled lesions

TineaFungal infections (ringworm, jock itch, athlete’s foot)Reddish discoloration, scaling, crustingTreat with antifungal agentPrevent recurrence by keeping skin dry

ImpetigoCaused by bacterial infectionMostly childrenReddish discoloration turns into blisters

and yellowish crustsIf turns systemic, it is life threatening

PsoriasisCause is unknown, probably geneticTriggered by trauma, infection, stress

Cutaneous inflammation, scaly lesions Due to excessive rate of epithelial cell growth

UrticariaHivesRaised, red lesions caused by blood vessel leakageSevere itchingCauses (hypersensitivity, allergic reactions, physical irritants, systemic disease)

SclerodermaAutoimmuneAffects blood vessels and CTHard skin lesionsMore common in women

Decubitus ulcers“bedsores” / pressure soresLack of blood flow causes tissue damage

Acne * Clogged sebaceous follicles from abnormal shedding of skin

cells * Bacteria build-up in sebaceous glands * Enhanced by hormones * Over the counter meds; sometimes Rx * Prevention

-avoid using oils, greasy moisturizers, facewash, and makeup

-wash hands before applying makeup-use non-scented ordinary mild soap-keep hands away from face