Integumentary System Vocabulary Flashcards

A comprehensive vocabulary flashcard set covering key terms, anatomical layers, accessory structures, functions, sensory receptors, and clinical conditions of the integumentary system.

Integumentary System

The organ system consisting of the skin, hair, nails, and exocrine glands that serves as the largest organ of the body.

Epidermis

The superficial layer of the skin composed of keratinized, stratified squamous epithelium that provides protection, a water barrier, and immunological defense.

Keratinocyte

A predominant epidermal cell type that manufactures and stores the protein keratin.

Keratin

An intercellular fibrous protein that provides hardness and water resistance to hair, nails, and skin.

Dermis

The middle layer of skin made of dense, irregular connective tissue housing blood vessels, hair follicles, sweat glands, and nerve structures.

Hypodermis

The layer beneath the dermis composed mainly of loose connective and adipose tissues that provides thermal insulation and physical cushioning.

Stratum Basale

The deepest layer of the epidermis consisting of cuboidal cells where active mitosis occurs.

Stratum Spinosum

The epidermal layer bound together by strong desmosomes where Langerhans cells are most commonly found.

Stratum Granulosum

The epidermal layer in which lipid granules are produced as keratinocytes mature.

Stratum Lucidum

A clear epidermal layer rich in lipids that is found only in thick skin.

Stratum Corneum

The outermost layer of the epidermis composed of dead cells filled with keratin that are continuously shed.

Melanin

A skin pigment produced by melanocytes in the stratum basale and absorbed by keratinocytes to protect against UV rays.

Fitzpatrick Skin Type

A classification system ranging from Type I to Type VI that categorizes human skin types according to their sensitivity to UV radiation and tanning capability.

Thick Skin

Skin featuring five epidermal layers (including stratum lucidum) found in high-friction areas such as fingertips, palms, and soles.

Thin Skin

Skin containing four epidermal layers, lacking the stratum lucidum layer, covering most of the body.

Langerhans Cell

An antigen-presenting dendritic immune cell found primarily in the stratum spinosum of the epidermis.

Papillary Layer

The superficial dermal layer made of loose connective tissue forming dermal papillae that supply nutrients to the epidermis and regulate temperature.

Reticular Layer

The deeper, denser dermal layer composed of dense collagen fiber bundles that gives skin structure, strength, and elasticity.

Hair Matrix

The growth zone of actively dividing cells located at the base of the hair bulb.

Arrector Pili Muscle

A smooth muscle associated with hair follicles that contracts to pull hair follicles erect.

Anagen Stage

The active growth phase of the hair growth cycle during which stem cells multiply and hair cells synthesize keratin, lasting 6 to 8 years in human scalp hair.

Catagen Stage

The degenerative phase of the hair cycle lasting 2 to 3 weeks in which mitosis ceases and the hair base keratinizes into a club hair.

Telogen Stage

The resting phase of the hair cycle lasting 1 to 3 months when the dermal papilla ascends to the bulge and the club hair falls out.

Nail Matrix

The proximal region beneath the nail fold where active mitosis occurs, giving rise to nail growth.

Nail Plate

The visible hard portion of the nail composed of clear, dead keratinized cells, including the free edge, nail body, and nail root.

Eccrine Sweat Gland

A coiled tubular gland in the dermis that secretes a watery, salt-containing sweat directly to the skin surface for thermoregulation.

Apocrine Sweat Gland

A gland located in hair-dense areas like armpits and groin that secretes an oily fluid containing pheromones into hair follicles.

Meissner Corpuscle

A tactile mechanoreceptor situated in dermal papillae responsible for sensing light touch.

Pacinian Corpuscle

A sensory receptor located deep within the dermis and hypodermis that senses deep pressure and vibration.

Cholecalciferol

A form of Vitamin D (Vitamin D3) synthesized in the epidermis from a steroid cholesterol precursor upon exposure to solar UV radiation.

Acne

A skin disorder resulting from overactive sebaceous glands, leading to plugged follicles, keratin accumulation, and inflammation.

Vitiligo

A skin condition characterized by localized loss of skin pigmentation due to the loss or functional failure of melanocytes.

Eczema

An inflammatory skin disorder characterized by an itchy, red, and flaky rash.

First-Degree Burn

A burn involving only the epidermis, causing redness, minor swelling, and pain, typically healing within days.

Second-Degree Burn

A partial-thickness burn extending into part of the dermis, producing painful blistering, redness, or white patches.

Third-Degree Burn

A full-thickness burn damaging the epidermis, the entirety of the dermis, and deeper tissues, requiring skin grafts and fluid management.

Autograft

A permanent skin graft harvested from another uninjured location on the same individual's body.

Homograft

A temporary skin graft obtained from an unrelated person of the same species (also called an allograft).

Heterograft

A temporary skin graft harvested from a different species (also known as a xenograft).

Rule of Nines

A clinical calculation tool used to estimate total body surface area percentage affected by burns in adult patients.