The Integumentary System

Vocabulary flashcards covering key terms from the lecture notes.

Integumentary system

External covering or skin.

Skin

Largest organ of the body; covers the outside and accounts for about 15% of body weight (about 20 pounds of a 145-pound person); thickness varies across the body.

Epidermis

Top layer of skin; full of ridges (fingerprints) that fit over the dermis' papillae.

Dermis

Middle layer of skin; contains fat, blood vessels, sweat and oil glands, and nerves.

Subcutaneous layer

Inner layer containing blood vessels, nerves, and hair follicles.

Arrector pili muscle

Small muscles attached to hair follicles that cause hair to stand up (goosebumps).

Melanin

Brown-black pigment produced by melanocytes; protects against sun damage.

Carotene

Yellow pigment contributing to skin color.

Blood vessels (in skin)

Presence affects skin coloration and can cause blushing and birthmarks.

Nerves

Skin contains about 72 feet of nerves per square inch and hundreds of receptors to detect touch, pressure, heat, cold, and pain.

Receptors (skin)

Sensory receptors in the skin that detect touch, pressure, heat, cold, and pain.

Sweat glands

Glands that cool the body by evaporation; about 700 per square centimeter.

Sebaceous glands

Oil glands associated with hair follicles.

Hair follicle

Structure from which hair grows; contains arrector pili muscle.

Nails

Protect fingertips; contain pigment for color and are attached to follicles with small muscles.

Bulla

Fluid-filled area greater than 5 mm across.

Crust

Collection of dried serum and debris; varies in size.

Excoriation

Area missing the epidermal layer; varies in size.

Fissure

Linear crack from epidermis to dermis; varies in size.

Macule

Round, flat area distinguished from surrounding skin by color; smaller than 1 cm.

Nodule

Elevated solid area deeper and firmer than a papule; greater than 5 mm across (e.g., wart, epidermal inclusion cyst).

Papule

Elevated solid area; 5 mm or less across; example: nevus (mole).

Pustule

Discrete, pus-filled raised area; varies in size (example: acne).

Tumor

Solid mass larger than 1–2 cm; benign epidermal tumor, basal cell carcinoma, or lipoma.

Ulcer

Deep loss of skin surface that may extend into the dermis; may bleed periodically and scar; varies in size.

Vesicle

Fluid-filled raised area; 5 mm or less across (examples: chickenpox, herpes simplex).

Wheal

Itchy, temporarily elevated area with irregular shape formed by localized skin edema (hives, insect bites).

Acne vulgaris

Inflammatory disease of follicles and sebaceous glands; mainly affects adolescents.

Alopecia

Loss of hair; two types: scarring (irreversible) and nonscarring (usually reversible).

Hirsutism

Excessive development of body hair that could be hereditary or due to an endocrine disorder.

Keloid

Scars that develop excess dense tissue as they heal.

Lyme disease

Tick-borne disease from a spirochete-infested deer tick.

Pediculosis

Infestation of parasitic lice (lice on body, head, or pubic region).

Pediculosis capitis

Head lice.

Pediculosis corporis

Body lice.

Pediculosis pubis

Pubic lice (crabs).

Poison ivy dermatitis

Dermatitis resulting from contact with the poison ivy plant.

Psoriasis

Chronic inflammatory skin condition with red papules and silvery scales.

Ringworm

Fungal infection forming flat lesions that may be dry/scaly or moist/crusty.

Rosacea

Chronic facial eruption with flushing, most common in middle-aged fair-skinned women.

Scabies

Skin infection caused by a mite; results in intense itching.

Urticaria

Also called hives; self-limiting allergic reaction with distinct wheals surrounded by reddened areas.

Verrucae

Warts; benign viral infection of the skin with a rough, elevated surface.

Wrinkles

Age-related changes: loss of elasticity due to sun exposure and decreased collagen.

Dermabrasion

Controlled scraping of the top skin layers to remove scars and smooth wrinkles.

Microdermabrasion

Noninvasive procedure using a spray of aluminum oxide crystals to remove the outer skin layer.

Chemical peel

Use of acids to remove damaged skin; levels include light, medium, and deep; may exfoliate and smooth skin.

Laser resurfacing

Pulsed laser to vaporize the skin's surface; removes blemishes and stimulates new cells and collagen.

Plastic surgery

Cosmetic surgery; reshaping of facial features.

Age-related skin changes

Infants have soft skin; teens may have acne; aging desk: less elastic skin, collagen loss, fragility, more pigmentation.

ABCDE rule (melanoma)

Assessment for moles: A asymmetry, B irregular border, C color variation, D diameter >6 mm, E evolving.