Chapter 5

Integumentary System

Colored People by D.C. Talk

• Pardon me, your epidermis is showing, sirI couldn’t help but note your shade of melaninI tip my hat to the colorful arrangementCause I see the beauty in the tones of our skin

We’ve gotta come togetherAnd thank the maker of us all

(chorus)We’re colored people, and we live in a tainted placeWe’re colored people, and they call us the human raceWe’ve got a history so full of mistakesAnd we are colored people who depend on a holy grace

[1, 1, 1, 1... 2, 2, 2, 2... 3, 3, 3, 3... 4, 4, 4, 4]

A piece of canvas is only the beginning forIt takes on character with every loving strokeThis thing of beauty is the passion of an artists heartBy gods design, we are a skin kaleidoscope

British twins with different skin color

We’ve gotta come together,Aren’t we all human after all?

(repeat chorus)

Ignorance has wronged some racesAnd vengeance is the lordsIf we aspire to share this spaceRepentance is the cure

[1, 1, 1, 1... 2, 2, 2, 2... 3, 3, 3, 3... 4, 4, 4, 4]

Well, just a day in the shoes of a color blind manShould make it easy for you to seeThat these diverse tones do more than cover our bonesAs a part of our anatomy

(repeat chorus)

We’re colored people, and they call us the human race[oh, colored people]We’re colored people, and we all gotta share this space[yeah we’ve got to come together somehow]We’re colored people, and we live in a tainted world[red and yellow, black and white]We’re colored people, every man, woman, boy, and girl[colored people, colored people, colored people, colored people, yeah]

Keratinized Stratified Squamous Epithelial Tissue

Epidermal Cells

Epidermal Cells• Keratinocytes

– Tightly packed; scale-like– Produced in the stratum basale– Work themselves upward to stratum corneum

(top layer) and then they die and fall off– Produce keratin (protein)

• Melanocytes– Spider shaped– Found in deepest layer (stratum basale)– Produce melanin (protein)

Epidermal Cells (cont.)

• Langerhan’s cells– Produced in the bone marrow– Migrate to the stratum spinosum– Star-shaped

• Merkel cells– Spiky hemisphere shape– Touch receptors (light touch; discrimination of

shapes and textures)

Cells of the Epidermis

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The Diversity of Keratin

Layers of the Epidermis

Dermis• Function – bind body

together; tough hide• Protein fibers:

Collagen – most abundant protein fiber; provides strength and resilience to prevent jabs and scrapes from entering the dermis

Elastin – allows stretch and recoil

• Contains 7 structures– Blood vessels– Nerve endings– Hair follicles– Oil glands– Sweat glands– Lymphatic vessels– Meissner's

corpuscles (touch receptors -detect pressure, vibrations)

2 Dermal LayersPapillary Layer

– Areolar Connective Tissue– Superficial, thin– Loosely woven mat of collagen and elastin

fibers; abundant blood vessels

- Dermal Ridges

• Add friction/increase grip strength• Combine with sweat to form fingerprints

Dermal Papillae and Fingerprints

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Areolar Connective Tissue

Dermis – 2nd Layer• Reticular Layer

–Dense Irregular Connective Tissue

–Deep and thick

–Thick collagen fibers interlocking to resist tension in many directions.

Dense Irregular Connective Tissue

Hypodermis• Not a part of the skin• Location – deep to the dermis• Tissue type – adipose• Functions- store fat, anchors skin to

muscles, insulation, prevents heat loss• Extra hypodermis storage areas

– Males- belly (anterior abdomen-”beer belly”)– Females – thighs, breasts– Cellulite – fat pushes up on dermis causing

bumps (“cottage cheese”) on outside of skin

Eccrine sweat glands

• Location - found everywhere but nipples and external genitalia– Most abundant: palms of hands, soles of

feet, forehead– Ducts terminate at skin pores– Function: Regulate body temperature

through evaporation (perspiration)– Sweat is 99% water; acidic (pH 4-6);

NaCl; urea

Eccrine Gland

Apocrine sweat glands

• Location – axilla and anogenital areas (armpits and groin)

• Duct opens into hair follicles

• Sweat contains lipids and proteins

• Sweat + bacteria = body odor

• Begin functioning at puberty

• Increased activity: pain, stress, sexual arousal

Sebaceous Oil Glands• Location – everywhere except palms/soles

• Most abundant- face, neck, upper chest

• Secrete sebum (oil) into hair follicle

or occasionally a skin pore

• Holicrine glands – don’t secrete; burst

• Become more active – puberty

• Positive – keep skin/hair soft, lubricated

• Negative – inflammation (acne) and (boils)

Sebaceous Oil Gland

SKIN CANCER

Skin Cancer

• Basal Cell Carcinoma– least malignant; most common – slow growth; shiny, dome-shaped– occur most on face

• Squamous Cell Carcinoma– Scaley, red, small, round– Rapid growth; can metastisize– Head, scalp, ears lower lip

Melanoma

• Highly metastatic and resistant to chemotherapy

• Mostly from moles

• A – asymmetric cancer of melanocytes

• B – border irregular

• C – color – contains several colors

• D – diameter larger than 6 mm

BURNS

Burns• Damage to the skin from intense heat,

electricity, radiation or chemicals

• First Degree: damage to epidermis only

• Second Degree: damage to epidermis and upper region of dermis; blisters

• Third Degree: full thickness burns

• Dehydration, shock; treated with I.V.

• Infection – main cause of death

Epidermal wound healing

These notes will be covered on the National Geographic assignment.

Deep wound healing

These notes will be covered in the National Geographic assignment.

Skin-related Diagnostic Terms• Cyanotic – skin appears blue b/c of lack of

oxygen in blood; heart failure and severe respiratory disorders

• Hematomas – Bruise; blood clotted beneath skin

• Jaundice – yellowish cast; accumulation of bile in blood; indicative of liver disorders - In dark-skinned individuals, examine mucous membranes and nail beds.

Vitiligo- Skin Pigmentation Disorder – loss of melanocytes and uneven dispersal of melanin

Albinism – genetic disorder; melanocytes do not make

melanin

BOTOX- removes frown lines, furrowed brows; the bacterium, Clostridium botulinum

inhibits muscles from contracting

Functions of the Integumentary System

• Protection

– Chemical – acidic; slows down bacterial growth melanin shields UV rays

– Physical – continuous barrier; prevents water loss

– Biological – fights viruses and bacteria that have entered body through the skin

Functions cont.• Body Temperature Regulation

–Perspiration (sweat) removes body heat – prevents overheating

• Cutaneous Sensation–Touch, pressure, pain

• Metabolic Functions–Produces vitamin D and proteins

(keratin, melanin, collagen, elastin)

Functions cont.

• Blood reservoir

–Holds about 5% of body’s total blood volume

• Excretion

–Through sweat, rids body of nitrogen wastes: ammonia, urea, and uric acid