Integumentary System - Vocabulary Flashcards

Vocabulary flashcards covering key terms from the integumentary system lecture notes.

Integumentary system

The skin and its accessory structures; the body's largest organ system.

Cutaneous membrane

The skin; outer covering composed of epidermis and dermis.

Epidermis

Outer protective layer of stratified squamous epithelium.

Dermis

Underlying layer of connective tissue with two regions: papillary and reticular.

Hypodermis

Subcutaneous layer (not part of the integument) made of loose connective tissue and fat.

Papillary layer

Superficial dermal layer of areolar tissue containing capillaries and Meissner’s corpuscles.

Reticular layer

Deeper dermal layer with dense irregular connective tissue and elastic fibers.

Areolar tissue

Loose connective tissue in the papillary layer of the dermis.

Dense irregular connective tissue

Tissue in the reticular layer with interwoven collagen and elastic fibers.

Stratum basale

Deepest epidermal layer; single row of basal cells undergoing rapid mitosis.

Basal cells

Cuboidal cells in the stratum basale that serve as stem cells for epidermis.

Keratinocytes

Most abundant epidermal cells; produce keratin.

Melanocytes

Melanin-producing cells in the stratum basale.

Melanin

Pigment that protects against UV; ranges from brown to black.

Melanosome

Vesicle that stores melanin inside melanocytes.

Merkel cells

Touch-sensitive cells in hairless skin that stimulate nerve endings.

Stratum spinosum

8–10 layers of keratinocytes bound by desmosomes; contains Langerhans cells.

Langerhans cells

Dendritic immune cells in the epidermis; present antigens.

Desmosome

Cell junction that binds keratinocytes together.

Stratum granulosum

3–5 layers; keratinocytes flatten and accumulate keratin and keratohyalin.

Keratinization

Formation of keratin-rich, protective epidermal layers.

Stratum lucidum

Clear layer in thick skin; cells are dead and contain eleidin.

Stratum corneum

Outermost keratinized layer; 15–30 layers; waterproofing and protection.

Glycolipids

Lipid components in the stratum corneum that help waterproof the skin.

Eleidin

Protein in the stratum lucidum aiding keratin maturation.

Epidermal ridges

Ridges that extend into the dermis to increase surface area for attachment.

Dermal papillae

Dermal protrusions between epidermal ridges; form fingerprints.

Fingerprint

Pattern formed by epidermal ridges and dermal papillae; used for identification.

Avascular

Lacking blood vessels; epidermal cells rely on diffusion from the dermis.

Meissner’s corpuscles

Touch receptors in dermal papillae for light touch.

Pacinian corpuscles

Deep pressure and vibration receptors in the reticular dermis.

Basal lamina

Basement membrane between the epidermis and dermis.

Hemidesmosome

Junction attaching epidermal cells to the basal lamina.

Hair follicle

Structure producing hair; includes root sheath, glassy membrane, and bulb.

Hair bulb

Base of the hair follicle surrounding the hair papilla.

Hair matrix

Region of rapidly dividing cells that produce hair.

Root hair plexus

Sensory nerves surrounding the hair bulb; detect touch.

Arrector pili

Smooth muscle that makes hair stand up when contracted.

Hair shaft

Portion of the hair that extends above the skin surface.

Nail

Thick sheets of keratinized epidermal cells on fingers and toes.

Nail body

Visible portion of the nail.

Nail bed

Skin beneath the nail body with rapidly dividing cells.

Nail root

Epidermal fold anchoring the nail bed, near the bone.

Lunula

Pale crescent area at the nail root; may be invisible in some nails.

Hyponychium

Free edge of the nail beneath the nail bed.

Eponychium

The cuticle; stratum corneum at the nail root.

Sebaceous gland

Oil gland; holocrine secretion producing sebum; associated with hair follicles.

Sebum

Oil that lubricates skin/hair; has antimicrobial properties.

Eccrine gland

Merocrine sweat gland; widely distributed; produces dilute sweat.

Merocrine

Secretion via exocytosis; used by eccrine glands.

Apocrine gland

Sweat glands in axillary and anogenital areas; secretions can odor due to bacteria.

Mammary gland

Specialized sweat gland that secretes milk.

Ceruminous gland

Modified sweat gland in the ear canal that produces cerumen.

Cerumen

Earwax.

Vitamin D3 synthesis

Skin-produced vitamin D3 upon UV exposure; precursor to calcitriol.

Calcitriol

Active vitamin D; essential for calcium metabolism.

Rickets

Vitamin D deficiency in children causing bone deformities.

Osteomalacia

Vitamin D deficiency in adults causing bone softening.

Melanoma

Malignant melanoma; cancer of melanocytes; high metastasis risk.

Basal cell carcinoma

Most common skin cancer from basal cells; rarely metastasizes.

Squamous cell carcinoma

Skin cancer from stratum spinosum; rarely metastasizes.

ABCDE

Mnemonic for melanoma signs: Asymmetry, Borders, Color, Diameter, Evolving.

Eczema

Allergic dermatitis with dry, itchy patches; treated with moisturizers and steroids.

Acne

Sebaceous gland–associated skin condition; pore blockage and bacterial infection.

Burns

Tissue damage from heat, chemicals, electricity, or radiation; classified by depth.

First-degree burn

Epidermis only; red and painful but usually heal without scarring.

Second-degree burn

Epidermis and part of the dermis; blisters common.

Third-degree burn

Full-thickness burn; destroys epidermis and dermis; often painless due to nerve destruction.

Fourth-degree burn

Extends to underlying muscle or bone.

Albinism

Genetic disorder with little or no melanin production.

Vitiligo

Patchy loss of pigment due to melanocyte dysfunction.

Scars

COLLAGEN-rich tissue formed during wound healing that lacks normal skin structure.

Keloids

Overgrowth of scar tissue extending beyond the wound boundary.

Bedsores

Decubitus ulcers from prolonged pressure causing tissue necrosis.

Decubitus ulcers

Another term for bedsores due to sustained pressure.

Stretch marks

Striae from dermal tearing during rapid growth or pregnancy.

Striae

Dermal tearing leading to stretch marks.

Calluses

Thickened skin from repeated abrasion.

Corns

Localized thickening due to constant pressure.

Moles (nevi)

Benign melanocytic growths; monitor for changes indicating cancer.