Skin:

Integumentary

System

Chapter 12

Related Combining Forms

Structure Related Combining Forms

Skin cutane/o, dermat/o, derm/o

Sebaceous glands seb/o

Sweat glands hidr/o

Hair pil/i, pil/o

Nails onych/o, ungu/o

Integumentary System

• Consists of skin and its related structures

(sebaceous glands, sweat glands, hair, and

nails)

• Average adult has two square yards of skin,

making it the largest body organ

Functions of Skin

• Keeps the body waterproof, hence preventing

fluid loss

• When intact, skin blocks the entrance of

pathogens

• Contains receptors for the sense of touch

• Synthesizes vitamin D from the sun

Functions of Related Structures

• Sebaceous glands

– Secrete sebum that lubricates skin and

discourages growth of bacteria on skin

• Sweat glands

– Assist with body water content and

temperature regulation

– Excretion of small amounts of metabolic

wastes

Functions of Related Structures

• Hair

– Helps control the loss of body heat

• Nails

– Protect dorsal surface of last bone of each toe

and finger

Structures of Skin and Its Related Structures

• Skin

– Specialized tissues

– Three layers

• Epidermis

• Dermis

• Subcutaneous

– (cutane: skin; -ous: pertaining to)

Structures of Skin and Its Related Structures

Epidermis

– (epi-: above or upon; derm: skin; -is: noun

ending)

• Outermost layer of skin

• Made of specialized epithelial tissues

• Contains no blood vessels or connective

tissue

• Depends on the lower layers for nourishment

Epidermis

• Epithelial tissues

– Form protective covering for internal and

external surfaces of the body

• Squamous epithelial tissue

– Forms upper layer of epidermis

– Flat, scaly cells continuously shed

Epidermis

• Basal layer

– Lowest layer of epidermis

– Site of new cell production

– When cells reach surface, they die and

become filled with keratin

• Keratin

– Fibrous, water-repellent protein

• Soft keratin: component of epidermis

• Hard keratin: found in hair and nails

Epidermis

• Melanocytes

– Special cells in basal cell layer

– Produce and contain dark brown to black

pigment known as melanin

• Melanin

– Pigment that determines color of skin,

produces freckles and age spots

– Protects skin from some of the harmful UV

rays

Dermis

• Directly below epidermis

• Contains connective tissue, blood and lymph

vessels, nerve fibers, hair follicles,

sebaceous glands, and sweat glands

• Sensory nerve endings

– Sensory receptors for touch, temperature,

pain, and pressure

Tissues Within Dermis

• Collagen

– Tough flexible fibrous protein found in skin,

bones, cartilage, tendons, and ligaments

• Mast cells

– Found in connective tissue of dermis

– Respond to injury, infection, or allergy by

producing and releasing heparin

(anticoagulant) and histamine (causes allergic

response)

Subcutaneous Layer

• Located below the layers of skin

• Connects skin to the surface muscles

• Made of loose connective tissue and adipose

tissue

• Lipocytes manufacture and store large

quantities of fat

– (lip/o: fat; -cytes: cells)

Sebaceous Glands

• Located in dermis

• Closely associated with hair follicles

• Sebum

– Oily substance released through ducts

opening into hair follicles

– Lubricates skin

– Acidic, thus discourages growth of bacteria on

skin

Sebaceous Glands

• Mammary glands

– Produce milk

– Also part of the reproductive system

Sweat Glands

• Sudoriferous glands

• Located on almost all body surfaces

• Two types

– Apocrine

• Found at hair follicles

– Eccrine

• Open onto skin

• Most numerous in palms, soles, and forehead

Sweat Glands

• Pores

– Opening on the surface of skin

– Act as ducts of the sweat glands

• Perspiration

– Secreted by sweat glands

– 99% water plus salt and metabolic waste

– Evaporation of sweat cools the body

Sweat Glands

• Hidrosis

– Production and excretion of perspiration

Hair

• Composed of dead protein cells filled with

hard keratin

• Color of hair determined by melanin

• Hair follicles

– Sacs holding the root of hair fibers

• Arrector pili

– Muscle fibers attached to hair follicles that

cause hair to stand erect, reducing heat loss

Nails

• Unguis (fingernail or toenail)

• Keratin plate protecting dorsal surface of the

last bone of each finger and toe

• Nail body

– Translucent

– Molded to surface of underlying tissues

– Make of hard, keratinized plates of epidermal

cells

Nails

Nails

• Nail bed

– Joins nail body to underlying connective

tissue

– Nourishes the nail

– Blood vessels provide pink color

• Free edge

– Portion of nail not attached to the nail bed

– Extends beyond tip of the finger or toe

Nails

• Lunula

– Half-moon-shaped region at nail root

– Site of new keratin cell formation

• (lun: moon; -ula: little)

• Cuticle

– Epidermis attached to the surface of nail

• Nail root

– Fastens nail to finger/toe

Medical Specialties Related to Integumentary System

• Dermatologist

– Specializes in diagnosing/treating disorders of

the skin

• (dermat: skin; -ologist: specialist)

• Plastic surgeon

– Specializes in surgical restoration or

reconstruction of body structures

• (-plasty: surgical repair)

Medical Specialties Related to Integumentary System

• Cosmetic surgeon

– Plastic surgeon who performs operations for

aesthetic rather than medical reasons

Pathology of Integumentary System

• Sebaceous Glands

– Acne vulgaris

• Chronic inflammatory disease caused by the

overproduction of sebum around the hair shaft

– Comedo

• Noninfected lesion composed of sebum and

keratin in hair follicle

• Closed comedo: whitehead

• Open comedo: blackhead

Sebaceous Glands

– Epidermoid cyst

• Closed sac just under the skin

• Contains fatty material

– Seborrhea

• Overproduction of sebum

• (seb/o: sebum; -rrhea: flow or discharge)

Sebaceous Glands

– Seborrheic dermatitis

• Inflammation causing scaling/itching of upper

layers of skin/scalp

– Seborrheic keratosis

• Benign skin growth having a waxy appearance

• Varied colors

• Common in elderly

Sweat Glands

– Anhidrosis

• Condition of lacking sweat in response to heat

– (an-: without; hidr: sweat; -osis: abnormal condition)

– Diaphoresis

• Profuse sweating

– (dia-: through or complete; phor: movement; -esis:

abnormal condition)

– Heat rash

• Itchy rash related to the blockage of sweat glands

by bacteria and dead cells

Sweat Glands

– Hyperhidrosis

• Excessive sweating in one area or over the whole

body

– (hyper-: excessive; hidr: sweat; -osis: abnormal

condition)

– Sleep hyperhidrosis

• Hyperhidrosis during sleep

Hair

– Folliculitis

• Inflammation of hair follicles

– (follicul: hair follicle; -itis: inflammation)

– Trichomycosis axillaris

• Superficial bacterial infection of hair shafts in areas

with extensive sweat glands, such as armpits

– (trich/o: hair; myc: fungus; -osis: abnormal condition;

axill: armpit; -ary: pertaining to)

Excessive Hairiness

– Hirsutism

• Excessive body and facial hair in women, usually

occurring in a male pattern

– (hirsut: hairy; -ism: condition)

Abnormal Hair Loss

– Alopecia

• Partial or complete loss of hair

– (alopec: baldness; -ia: condition)

– Alopecia areata

• Autoimmune disorder attacking hair follicles

• Occurs in patches on scalp or elsewhere on body

Abnormal Hair Loss

– Alopecia totalis

• Loss of all hair on the scalp

– Alopecia universalis

• Total loss of hair on all parts of the body

– Androgenic alopecia

• Hair loss due to hormonal changes

• Occurs in males and females

Nails

– Clubbing

• Abnormal curving of nails

• Often accompanied by enlargement of fingertips

• May be hereditary

• May be due to changes associated with oxygen

deficiencies related to coronary or pulmonary

disease

Nails

– Koilonychia

• Outer surface of nail is concave

• Often indicates iron-deficiency anemia

– (koil: hollow or concave; onych: fingernail or toenail; -ia:

condition)

– Onychia

• Inflammation of matrix of nail

• May result in the loss of nail

Nails

– Onychocryptosis

• Edges of toenail curve inward and cut into the skin

– (onych/o: fingernail or toenail; crypt: hidden; -osis:

abnormal condition)

– Onychomycosis

• Fungal infection of nail

– (myc: fungus)

– Paronychia

• Infection of skin fold around a nail

– (par-: near)

Skin Pigmentation

• Acanthosis nigricans

– Development of dark wart-like patches on one

or more areas of skin

• Age spots

– Discoloration caused by sun exposure

• Albinism

– Genetic condition characterized by lack of

pigment in skin, hair, and irises of eyes

• (albin: white)

Skin Pigmentation

• Chloasma

– Brownish spots on face

– May occur during pregnancy, and disappear

after delivery of infant

• Vitiligo

– Irregular patches of white skin related to

destruction of melanocytes

Bleeding into Skin

• Contusion

– Injury to underlying tissues without breaking

the skin

– Discoloration caused by accumulation of

blood within the skin

• (contus: bruise; -ion: condition)

Bleeding into Skin

• Ecchymosis

– Large, irregular purplish discoloration due to

bleeding under the skin

• (ecchym: pouring out of juice; -osis: abnormal

condition)

• Purpura

– Multiple purple discoloration on skin due to

bleeding underneath the skin

• (purpur: purple; -a: noun ending)

Bleeding into Skin

Bleeding into Skin

• Petechiae

– Small, pinpoint hemorrhages less than 2 mm

in diameter

• Hematoma

– Usually due to injury

– Swelling of clotted blood trapped in tissues

– Blood is reabsorbed

• (hemat: blood; -oma: tumor)

Surface Lesions

• Crust

– Collection of dried serum and cellular debris

• Erosion

– Wearing away of a surface

• Macule

– Flat, discolored spot less than 1 cm in

diameter

Surface Lesions

Surface Lesions

• Nodule

– Solid, raised skin lesion larger than 0.5 cm in

diameter

• Papule

– Raised, red lesion less than 0.5 cm in

diameter

– Does not contain pus

Surface Lesions

• Plaque

– Scaly, solid raised area of closely spaced

papules

• Scales

– Flakes or dry patches of excess dead

epidermal cells

– Some shedding is normal

– Excessive shedding associated with the skin

disorders

Surface Lesions

• Verrucae

– Small, hard skin lesions caused by human

papillomavirus

– Also known as warts

• Wheal

– Small, itchy bump

– May be due to an allergic reaction

Fluid-Filled Lesions

• Abscess

– Closed pocket containing pus

– Due to bacterial infection

• Purulent

– Producing or containing pus

• Exudate

– Fluid leaking out of an infected wound

Fluid-Filled Lesions

• Cyst

– Abnormal sac containing fluid, or semisolid

material

• Pustule

– Small, circumscribed lesion containing pus

– Contained within a limited area

Fluid-Filled Lesions

Fluid-Filled Lesions

• Vesicle

– Blister, less than 0.5 cm in diameter

– Contains watery fluid

• Bulla

– Large blister more than 0.5 cm in diameter

Lesions Through Skin

• Abrasion

– Superficial layers are scraped away

• Fissure

– Crack-like break in the skin

• Laceration

– Torn or jagged wound

Lesions Through Skin

Lesions Through Skin

• Pressure sore

– Open ulcerated wound caused by the

prolonged pressure on an area of the skin

• Needlestick injury

– Accidental puncture wound caused by

hypodermic needle

• Ulcer

– Open lesion resulting in tissue loss around the

edges

Birthmarks

• Pigmented birthmarks

– Also known as moles or café-au-lait spots

• Vascular birthmarks

– Caused by blood vessels close to the skin's

surface

Birthmarks

• Capillary hemangioma

– Soft, raised, pink or red vascular birthmark

– Benign tissue mass

• (hem: blood; angi: blood or lymph vessels; -oma:

tumor)

• Port-wine stain

– Flat vascular birthmark made up of dilated

blood capillaries

– Creates reddish-purple discoloration

Dermatitis

• Inflammation of the skin

• Contact dermatitis

– Localized allergic response

• (dermat: skin; -itis: inflammation)

• Eczema

– Recurring dermatitis characterized by

redness, itching, and dryness

Dermatitis

• Exfoliative dermatitis

– Widespread scaling of the skin

• Pruritus

– Itching associated with the most forms of

dermatitis

• (prurit: itching)

Erythema

• Redness of skin due to capillary dilation

– (erythem: flushed; -a: noun ending)

• Erythema infectiosum

– Mildly contagious viral infection common in

children

– Also known as fifth disease

Erythema

• Erythema multiforme

– Generalized allergic reaction to illness,

infection, or medication

• Erythema pernio

– Purple-red inflammation occurring when small

blood vessels below the skin are damaged

Erythema

• Erythroderma

– Abnormal redness of entire skin surface• (erythr/o: red; -derma: skin)

• Exanthem

– Widespread rash

• Hand, foot, and mouth disease

– Mild viral infection common in children under 5 years of age

– Sores in mouth/throat; rash on hands/feet

General Skin Conditions

• Dermatosis

– Denotes skin lesion or eruption of any type

not associated with inflammation

• Ichthyosis

– Hereditary disorders characterized by dry,

thickened, scaly skin

• (ichthy: dry or scaly; -osis: abnormal condition)

General Skin Conditions

• Lipedema

– Characterized by accumulation of fat and fluid

in tissues under the skin of hips and legs

• (lip: fat; -edema: swelling)

• Systemic lupus erythematosus

– Autoimmune disorder characterized by red,

scaly rash on face/upper trunk

• Psoriasis

– Occurrence of red papules with silvery scales

General Skin Conditions

• Roseacea

– Tiny red pimples and broken blood vessels

– Commonly seen in adults 30–60 years of age

• Rhinophyma

– Hyperplasia of tissues of nose

– Usually seen in older men

• (rhin/o: nose; -phyma: growth)

General Skin Conditions

• Scleroderma

– Autoimmune disorder in which connective

tissues become thickened and hardened

• (scler/o: hard; -derma: skin)

• Urticaria

– Itchy wheals due to allergic reaction

• (urtic: rash; -aria: connected with)

General Skin Conditions

• Xeroderma

– Excessively dry skin

• (xer/o: dry; -derma: skin)

Bacterial Skin Infections

• Carbuncle

– Cluster of furuncles

• Cellulitis

– Acute bacterial infection within connective

tissues

– Characterized by malaise, swelling, warmth,

and red streaks

Bacterial Skin Infections

• Furuncles

– Large, tender, swollen areas caused by

staphylococcal infection around hair follicles

or sebaceous glands

• Gangrene

– Death of tissue, followed by bacterial

invasion, which may also enter bloodstream

– Commonly due to the loss of circulation to the

affected tissues

Bacterial Skin Infections

• Impetigo

– Highly contagious bacterial skin infection

– Common in children

• Necrotizing fasciitis

– Caused by Group A strep that enters the body

through a skin wound

Bacterial Skin Infections

• Pyoderma

– Acute, pus-forming bacterial skin infection

• (py/o: pus; -derma: skin)

Fungal Skin Infections

• Mycosis

– Abnormal condition caused by fungus

• (myc: fungus; -osis: abnormal condition)

• Tinea

– Fungal infection on skin, hair, or nails

– Known as ringworm

Parasitic Skin Infestations

• Pediculosis

– Infestation with lice

• (pedicul: lice; -osis: abnormal condition)

• Scabies

– Skin infection caused by itch mites

Skin Growths

• Callus

– Thickening of the part of the skin caused by

repeated rubbing

• Cicatrix

– Normal scar

• Granulation tissue

– Forms during healing of a wound

Skin Growths

• Granuloma

– Small swelling of granulation tissue

– May result from inflammation, injury, infection

• (granul: granular; -oma: tumor)

• Keloid

– Thickened scar expanding beyond the

boundaries of original incision

• (kel: growth or tumor; -oid: resembling)

Skin Growths

• Keratosis

– Overgrowth and thickening of the skin

• (kerat: hard or horny)

• Lipoma

– Benign fatty tumor located between the skin

and muscle layer

• Nevus

– Small, dark skin growth developing from

melanocytes

Skin Growths

• Dysplastic nevi

– Atypical moles

– May develop into skin cancer

• Papilloma

– Benign wart-like growth on epithelial tissue or

elsewhere in the body

• (papill: resembling a nipple; -oma: tumor)

Skin Growths

• Polyp

– Mushroom-like growth from the surface of

mucous membrane

• Skin tags

– Flesh-colored polyps hanging from the body

by fine stalks

– Benign

– Tend to enlarge with age

Skin Cancers

• Malignant growth on skin

• Three types

– Basal cell carcinoma

– Squamous cell carcinoma

– Melanoma

Skin Cancers

• Actinic keratosis

– Precancerous skin growth occurring on sun-

damaged skin

– Lack of treatment may lead to cancer

• Basal cell carcinoma

– Malignant tumor of basal cell layer of

epidermis

– Rarely spreads

Skin Cancers

• Squamous cell carcinoma

– Malignant tumor of squamous cells of

epithelium

– Can spread quickly to other body systems

• Malignant melanoma

– Occurs in melanocytes

– Initial symptoms are change in the size,

shape, or color of a mole

• (melan: black; -oma: tumor)

Burns

• Injury caused by heat, flame, electricity, sun,

chemicals, or radiation

• Severity described according to the

percentage of the total body skin surface

affected or by depth or layer of skin involved

Diagnostic Procedures of Integumentary System

• Biopsy

– Removal of small piece of living tissue for

confirmation of diagnosis

• (bi: pertaining to life; -opsy: view of)

• Exfoliative cytology

– Cells are scraped from tissue for microscopic

examination

Treatment Procedures of Integumentary System

• Preventive measures

– Sunscreen

• Blocks harmful ultraviolet B (UVB) rays or

ultraviolet A (UVA) rays

• Measured in terms of strength of sun protection

factor (SPF)

Burn Treatment

– Depends on degree of burn, and percentage

of the body surface involved

– Burn centers provide pain relief, debridement,

dermoplasty, IV fluids and nutritional

supplements, antibiotics, cosmetic

reconstruction, and rehabilitation

Tissue Removal

– Cauterization

• Destruction of tissue by burning

– Chemabrasion

• Use of chemicals to remove outer layers of skin

– Cryosurgery

• Destruction or elimination of abnormal tissue cells

– (cry/o: cold; -surgery: operative procedure)

Tissue Removal

– Curettage

• Removal of surface material by scraping

– Debridement

• Removal of dirt, foreign objects, damaged tissue,

and cellular debris from a wound

• Prevention of infection and promotion of healing

– Irrigation and debridement

• Pressurized fluid to clean wound debris

Tissue Removal

– Dermabrasion

• Involves use of revolving wire brush or sandpaper

– Electrodesiccation

• Destruction of tissue by the use of electric spark

– Incision

• Use of surgical instrument to cut open a lesion

Tissue Removal

– Mohs' surgery

• Layers of cancerous tissue are removed and

examined under the microscope

• Procedure is repeated until margin that is clear of

all cancerous tissue is achieved

Laser and Light Source Treatments of Skin Conditions

• Laser (Light Amplification by Stimulated

Emission of Radiation)

– Laser tube filled with solid, liquid, or gas

substance is stimulated to emit light at a

specific wavelength

• Photosensitizing drug

– Administered topically or by injection

– After activation, drugs produce a form of

oxygen that kills nearby cells

Medications for Treatment of Skin

• Retinoids

– Derived from vitamin A and are used because

of their effect on epithelial cell growth

• Topical steroids

– Derivatives of natural corticosteroid hormones

– Treatment of various skin disorders

Cosmetic Procedures

• Blepharoplasty

– Surgical reduction of upper and lower eyelids

by removing sagging skin

• (blephar/o: eyelid; -plasty: surgical repair)

• Botox

– Used to reduce moderate-to-severe frown

lines, to treat migraines and muscle spasms

• Collagen replacement therapy

– Used for soft-tissue augmentation

Cosmetic Procedures

• Dermatoplasty

– Replacement of damaged skin of a patient

with the healthy tissue taken from a donor site

• Electrolysis

– Use of electric current to destroy hair follicles

• Lipectomy

– Surgical removal of fat from beneath the skin

to improve physical appearance

Cosmetic Procedures

• Liposuction

– Surgical removal of fat beneath the skin with

the aid of suction

• Rhytidectomy

– Surgical removal of excess skin and fat from

the face

• (rhytid: wrinkle; -ectomy: surgical removal)

Cosmetic Procedures

• Sclerotherapy

– Injection of a saline sclerosing solution for

treatment of spider veins (nonessential veins

seen through the skin)