integumentary_system.ppt

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Integumentary

System

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Integumentary System

 Skin

 Hair

 Nails

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Membranes



Epithelial membranes

– Cutaneous_Cutaneous – MucousMucous

– Serous Serous

 Parietal vs visceral_{Parietal vs visceral}

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Integumentary System



Skin (cutaneous membrane)



Main layers – superficial to deep



Epidermis



Dermis



Hypodermis

-not always

considered

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Functions of Skin

 Protection  Sensation

 Movement without energy  Excretion

 Vitamin D production – needed to absorb calcium

Sun+Skin Vit D blood kidney/liver calcitriol blood regulates calcium & phosphorous

 Immunity

 Healing Wounds

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Skin Structure

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Epidermis



Epidermis – outer layer

 Keratinized stratified squamous epithelium

 Avascular (hardened by keratin)

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Epidermis – cell types

 Keratinocytes

 produce keratin – waterproofing protein

 Originate in deeper layers & get pushed to surface – becomes keratin filled & dies

 Connected to each other by

desmosomes & tight junctions

 Cell production & keratinization are accelerated in areas of friction

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Epidermis – cell types

•

Melanocytes

•

Produce melanin

•

Prevents DNA mutation from the UV

radiation

•

UV increases melanin production

•

Same number in everyone, but

different amount of pigment produced

•

Accumulation of melanin results in

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Epidermis – Skin Color

 Determined by three factors:  Types of pigments present

 Melanin – brown, black, or yellow pigment

 Carotene

 Hemoglobin

 Blood circulation

 Stratum corneum thickness

 Orange-yellow pigment from some vegetables

 Vitamin A precurser – vitamin A forms retinal which is needed for sight

 Accumulates in adipose and stratum corneum cells

 Red, oxygen-carrying pigment in erythrocytes

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Skin as a Diagnostic

 Skin color is influenced by emotional & disease states: You should know the states that cause these.

 Cyanosis – bluish color - lack of oxygen

 Erythema – redness – heat, inflammation, fever

 Albinism – genetically black, but white – no melanin produced from melanocytes

 Pallor – paleness – lack of blood flow

 Jaundice – yellowish color – liver damage; accumulation of bilirubin

(13)

5 strata of the Epidermis – Deep to Superficial

 Stratum basale

 highly mitotic (produces new skin layer)

 ~ 25% melanocytes

 Stratum spinosum  Slightly mitotic

 Contains Langerhan’s macrophages

 Several layers of many sided cells (looks spiny)

 Stratum granulosum

 Also contains Langerhans cell

 contains keratohyalin (helps form keratin)

 Stratum lucidum

 ONLY found in thicker epidermis – palms, soles, callus

 Completely keratinized (and dead!)

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5 strata of the Epidermis



Stratum corneum

 Outermost layer

 Also completely keratinized

 Dead cells

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Dermis



Middle layer of skin



Contains hair folllicles, glands, nerves,

vessels, muscle



All four tissue types present

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Dermis



Papillary layer

 Contains Areolar CT

 Dermal papillae

Indent into epidermis

forms fingerprints

Important for grip

Contains blood vessels

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Dermis



Reticular layer



Dense irregular CT



contains blood vessels, nerves,

glands, adipose



Pacinian Corpuscles – nerve endings

responsible for sensitivity to deep

pressure touch and high frequency

vibration



Collagen – prevents overstretching

and tearing of skin



Elastin – allows skin to stretch

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Hypodermis

 Not usually considered part of the skin  Also called subcutaneous layer

 Site of subcutaneous injections – absorbed directly into blood stream

 Anchors skin to underlying organs, shock absorption, insulation

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Appendages of the Skin

Hair

 Minor protective functions (retain heat, decrease sunburn, eyelashes protect eyes)

 Structure

 shaft – projects from skin

 follicle – extends into dermis

 root – lies within the follicle

 bulb – contains CT, vessels and nerves

 sebaceous gland – lubricates hair

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Appendages of the Skin

 Hair Growth

 influenced by: (in this order)

 nutrition - main influence

 hormones

 blood flow

 baldness ( alopecia )

 male pattern baldness - sex linked recessive genetic trait

 thinning – can be caused by medications, nutrition, stress, etc.

 Hair Pigment

 caused by proportions of 3 melanin types

 dark hair – true melanin

 blonde and red – melanin with iron and sulfur

(29)

Appendages of the Skin

Nails

 Scale-like modifications of the epidermis

 Heavily keratinized

 Stratum basale extends beneath the nail bed to form nail matrix

 Responsible for growth ( matrix region)

 Lack of pigment makes them colorless

 Lunula “little moon” – area of cell growth (white semicircle at base of nail)

(30)

Nail Structures

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Sweat Glands

 Eccrine glands

 Widely distributed in skin: abundant on palms, soles, forehead

 Sweat composition: mostly water with a slightly acidic 4-6 pH

 Function: thermoregulation • Apocrine glands

 Ducts empty into hair follicles

 Found mainly in anogenital & axillary region

 Begin to function at puberty due to hormones / pheromones

 Organic contents: Fatty acids and proteins – can have a yellowish color that stains clothes

 Odor is from associated bacteria  Ceruminous glands

 Modified apocrine gland

 Found in outer 1/3 of ear canal

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Appendages of the Skin



Sebaceous glands



all over except palms and soles of feet

 Produce oil for waterproofing

 Lubricant for skin & kills bacteria

 Most with ducts that empty into hair follicles

 Glands are activated at puberty: stimulated

by hormones

 Acne – active infection of sebaceous

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Burns

 Protein denaturation and cell death caused

by heat, electricity, UV radiation, or chemicals

 2 main dangers

 Dehydration–Loss of fluids & Electrolytes lead to: Renal Shutdown

Circulatory shock

 Infection

(36)

Rules of Nines



Way to determine the extent of burns



Primary importance is to estimate

fluids needed for rehydration



Body is divided into 11 areas for quick

estimation

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Partial Thickness Burns

Slide 4.27



First-degree burns

 Only epidermis is damaged

 Local redness, swelling, & pain

 Usually heal in 2-3 days (short time period)

(40)

Partial Thickness Burns



Second degree burns

 Epidermis and dermis & structures within dermis are damaged

 Appearance of blisters of

any size

 Skin regeneration in

3-4 weeks with some scarring

 There is a danger of

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Full Thickness Burns



Third-degree burns

 Epidermis, Dermis, Hypodermis and all

structures within are completely destroyed

 Usually painless at site of burn due to

destruction of sense receptors

 Burn is gray-white, tan, brown, black, or

deep cherry red

 Surrounded by areas of 1st & 2nd degree

burns that will be painful

 Treatments are numerous but will involve

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Skin Cancer

Skin cancer is the most common type of cancer

Skin cancer is the most common type of cancer

2 out of 5 cancers are skin cancers

(58)

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

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Skin Cancer Types

Basal cell carcinoma

 Least malignant

 Most common type (90% of skin cancers)

 Arises from stratum basale

 cannot produce keratin

 Boundary lost between dermis and epidermis

 Seldom metastasizes – treated surgically or by radiation – 99% cure rate if caught early

 Signs

 Pale marks

 Reddish patches

 Round, smooth growth with raised edge

 Shiny bumps

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Skin Cancer Types

 Squamous cell carcinoma

 2nd most common skin cancer

 Highest risk – fair skin, light hair, blue/green eyes

 Arises from stratum spinosum

 Metastasizes to lymph nodes if left untreated

 1500-2000 deaths in US per year

 Early removal allows a good chance of cure

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Cumulative Effects

IMPORTANT TO KNOW



Basal cell & squamous cell carcinomas are

due to cumulative effects of the sun’s

radiation (or chemical exposures as well)



These tend to develop in ages 30-40s

after years of daily sun exposure

(65)

Skin Cancer Types



Malignant melanoma

 Least common

 most deadly of skin cancers

 Originates melanocytes

 Metastasizes rapidly to lymph and blood

vessels

(66)

Intensive Effects



Malignant Melanoma tends to occur in

younger ages (as well as older people)



It is due to brief intense exposures (aka:

sunburns)



This is the most serious form of skin

cancer and MUST be caught early to be

treated successfully!

(67)

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)

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Prevention

 Wear sunscreen whenever outside or cover upWear sunscreen whenever outside or cover up

 avoid midday sun between 10-2 and beware of reflected avoid midday sun between 10-2 and beware of reflected

light

 higher altitudes - every 1000 ft above sea level, higher altitudes - every 1000 ft above sea level,

radiation increases 4-5 %

 Be cautious about tanning bedsBe cautious about tanning beds

 Medications - tetracycline (antibiotics), Retin A, birth Medications - tetracycline (antibiotics), Retin A, birth

control, antidepressants,

 diuretics, and anti-inflammatories cause photosensitivitydiuretics, and anti-inflammatories cause photosensitivity  avoid sunburnsavoid sunburns

 examine skin regularly - remember ABCD rule – examine skin regularly - remember ABCD rule –

have full body check by dermatologist once a

have full body check by dermatologist once a

year

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Other

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 Contact dermatitis (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

 Benign neoplasms, but can turn malignant

 Contagious

 Remove by freezing, drying, laser therapy, chemicals

 Boils

 Bacterial infection that infects hair follicles

(74)

Tinea

Fungal infections (ringworm, jock itch, athlete’s foot) Reddish discoloration, scaling, crusting

Treat with antifungal agent

Prevent recurrence by keeping skin dry

Impetigo

Caused by bacterial infection Mostly children

(75)

Psoriasis

Cause is unknown, probably genetic Triggered by trauma, infection, stress

Cutaneous inflammation, scaly lesions

Due to excessive rate of epithelial cell growth

Urticaria

Hives

Raised, red lesions caused by blood vessel leakage Severe itching

Causes (hypersensitivity, allergic reactions, physical irritants, systemic disease)

Scleroderma

Autoimmune

Affects blood vessels and CT Hard skin lesions

More common in women

Decubitus ulcers

“bedsores” / pressure sores

(76)

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