Pathology of Medical Terminology - Chapter 4: The Integumentary System

Integumentary System

Function of the Skin

• Physical barrier protecting from:

  • Microorganism invasion

  • Harmful UV rays (melanin shields DNA)

  • Dehydration

• Participates in vitamin D production.

• Assists in thermoregulation (sweating).

• Sensory nervous system structures communicate environmental information.

Skin Structure

• Largest organ in the body, weighing about 20 pounds in larger individuals.

• Includes epidermis, dermis, and accessory organs (nails, hair, glands).

• Epidermis: Superficial layer, exposed to the external environment.

• Dermis: Layer below the epidermis, containing hair roots, follicles, and glands.

  • Pseudoriferous glands (sweat glands): Coiled structures that secrete sweat directly onto the skin surface for thermoregulation.

  • Sebaceous glands (oil glands): Lumpy structures attached to hair follicles; secrete oil (sebum) to protect and hydrate the skin, preventing bacterial colonization.

  • Nerve fibers: Transmit sensations like pain, touch, and pressure.

  • Arrector pili muscle: Smooth muscle connected to hair follicles; contracts in response to nervousness or excitement, causing goosebumps.

• Hypodermis (subcutaneous or sub-q layer):

  • Adipose tissue (fat cells or adipocytes).

  • Not technically part of the skin, but considered alongside it.

  • Contains adipocytes (fat cells) that appear as clear bubbles under a microscope because lipids don't pick up stains.

    

Hair

• Composed of keratinized cells from hair follicles.

• Keratin: Insoluble, tough, filamentous protein found in hair, epidermis, and nails.

• Keratinocytes: Cells that produce keratin, making up 90% of the epidermis, providing a tough and waterproof barrier.

Melanocytes

• Located in the deeper part of the epidermis.

• Produce melanin, a dark pigment that gives skin its color.

Glands

• Sebaceous glands (oil glands):

  • Secrete sebum (oil) onto hair follicles, which then spreads to the skin surface.

  • Protect the skin and prevent dehydration.

• Pseudoriferous glands (sweat glands):

  • Secrete sweat directly onto the skin surface for cooling and thermoregulation.

Nails

• Translucent plates made of sturdy keratin.

• Protect the ends of fingers and toes and aid in manipulating the environment.

Combining Forms

• cryo: cold

• cyano: blue

• dermo, dermato, cutanio: skin

• hydro or hydro: sweat

• kerato, sclero: hard

• myco: fungus

Examples

• mycohemia: fungal infection in the blood.

• onychomycosis: fungal infection of the nails (onycho- nail, mycosis- fungal condition).

• scleroderma: hardening of the skin (sclero- hard, derma- skin).

• hydrocystomas: benign cysts of sweat ducts, often on eyelids (hydro- sweat).

• cryosurgery: using cold to remove skin abnormalities.

• pachyonychia: thickening of the nails (pachy- thick, onycho- nail).

Additional Combining Forms

• pachy, pachyo: thick (like pachyderms - rhinos, elephants)

• pio: pus

• rigiddo: wrinkle

• sibo: sebum (oil)

• tricho: hair

• zero: dry

Examples

• rhinidectomy: surgical removal of wrinkles (rhinido- wrinkle).

• Trichomonas vaginalis: parasitic infection with hair-like flagella (tricho- hair).

• xeroderma: very dry skin (xero- dry, derma- skin).

Prefixes

• a or an: without, not

• bio: life

• epi: on, upon

• para: around, beside, near, close by

• sub: below, beneath

Suffixes

• derma: skin condition

• malatia: softening

• Plagia: formation or growth

• phagia: to eat or bite

• plasty: surgical repair or reconstruction

• rhea: discharge or flow

• tome: an instrument that's used to cut

Examples

• xeroderma: dry skin (xero- dry, derma- skin).

• onychomalacia: softening of the nails (onycho- nail, malacia- softening).

• onychophagia: nail-biting (onycho- nail, phagia- eating).

Skin Condition Adjectives

• atypical: unusual

• circumscribed: contained in a specific area

• indurated: hardened tissue

• purulent: containing pus

• Diaphoresis: profuse sweating

• Eschar: blackened or burned tissue

• Pallor: abnormally pale skin coloration

• Pruritic: pertaining to itching

• Turgor: taut and full

• Adipose: fat or fatty

Injury Terms

• Abrasion: superficial scrape of the skin.

• Burn: injury caused by heat, chemicals, or electricity.

  • Superficial (first-degree): involves only the epidermis.

  • Partial thickness (second-degree): penetrates into the dermis.

  • Full thickness (third-degree): extends beyond the dermis, involving nerve structures.

• Cycotrix: scar tissue replacing normal tissue.

• Contusion: injury without breaking the skin (bruise).

• Excoriation: scratch mark.

• Fissure: deep cleft or slit in the skin, often due to dryness.

Infection-Related Terms

• Abscess: localized collection of pus caused by bacterial infection (boil).

• Furuncle: infection of a hair follicle.

• Carbuncle: collection of interconnected furuncles forming a large pocket of pus.

• Cellulitis: fluid collection in the subcutaneous layer due to inflammation, often caused by infection.

• Herpes: viral infection causing skin problems.

  • Herpes simplex (HSV): causes cold sores and genital sores.

  • Herpes zoster: causes shingles, reactivation of the chickenpox virus.

• Impetigo: contagious bacterial skin infection, often with honey-colored crust.

• Jaundice (xanthoderma): abnormal yellowing of the skin and eyes due to bilirubin accumulation.

Medical Conditions (Raised or Elevated Lesions)

• Keloids: overgrowth of collagen forming scar tissue beyond the wound boundaries.

• Cyst: closed sac containing liquid or semi-liquid substance.

• Acne: inflammation of sebaceous glands and hair follicles, marked by papules and pustules.

  • Papule: small, raised, solid circular area.

  • Pustule: elevation of skin containing pus.

• Verruca: (wart) flesh-colored elevation caused by a virus (HPV).

• Vesicles: (blister) clear fluid-filled raised lesion.

• Wheel: raised reddish patch (hive).

• Urticaria: eruption of itchy wheels (hives), often related to allergies.

• Eczema (dermatitis): inflammatory condition causing redness, scaling, itching, and burning.

Medical Conditions (Pigmentation)

• Albinism: genetic disorder characterized by lack of melanin production in skin, hair, and eyes.

• Vitiligo: patchy loss of skin pigmentation due to melanocyte failure.

Tests and Procedures

• Biopsy (BX): removal of skin for microscopic examination.

• Frozen section (FS): thin slice of tissue cut from a frozen specimen for microscopic diagnosis.

• Scratch test: allergy test where allergens are applied to scratched skin.

• Tuberculosis skin test (TB test, PPD): intradermal test to determine TB exposure.

Surgeries and Procedures

• Dermatoautoplasty: skin graft using the patient's own skin (auto- self).

• Dermatoheteroplasty: skin graft using skin from another source (hetero- different).

• Dermatome: instrument for cutting thin slices of skin for grafting.

• Dermatoplasty: surgical repair of the skin.

• Rididectomy: surgical removal of wrinkles (facelift).

• Suture: uniting two surfaces by sewing.

Medications and Drug Therapies

• Antifungals: treat fungal infections (paronychia, tinea capitis, tinea pedis).

  • tinea capitis: fungal infection of the scalp (capit- head).

  • tinea pedis: athlete's foot (pedo- foot).

• Anti-inflammatories: treat acne, cellulitis, eczema, and other inflammatory skin conditions.

• Antipruritic: medication to stop itching.

• Pediculous side: kills lice.

• Steroids: anti-inflammatory agents.

Specialties

• Dermatology: medical specialty focusing on the skin.

• Dermatologist: physician specializing in dermatology.

• Medical aesthetician: licensed professional in cosmetic beauty specializing with skin.

Abbreviations

• BX: biopsy

• CNS: culture and sensitivity

• ED and C: electrodesiccation and curettage

• FS: frozen section

• I and D: incision and drainage

• PPD: purified protein derivative