Integument System - Vocabulary Flashcards

Vocabulary flashcards covering skin structure, layers, glands, hair, burns, and key functions.

Epidermis

Outer, keratinized stratified squamous epithelium; 4–5 layers depending on thick vs thin skin.

Dermis

Middle skin layer containing vessels, nerves, and accessory structures; two layers: papillary and reticular.

Hypodermis

Subcutaneous layer mostly adipose tissue; anchors skin to underlying tissues.

Stratum Basale

Deepest epidermal layer; single layer of cuboidal cells that produce keratinocytes; contains melanocytes and Merkel cells.

Stratum Spinosum

'Spiny' layer; ~10 layers of keratinocytes; contains Langerhans cells.

Stratum Granulosum

Granular layer; 3–5 cell layers of keratinocytes with keratin granules.

Stratum Lucidum

Clear layer present only in thick skin (palms/soles); dead, flattened keratinocytes; no nuclei.

Stratum Corneum

Horny layer; 10–30 layers of dead keratinocytes; undergoing cornification; forms water-resistant barrier; renews ~every 4 weeks.

Keratinocytes

Most abundant epidermal cells; produce keratin; give hair, nails, and skin hardness and water resistance.

Melanocytes

Produce melanin; determine skin color and provide UV protection.

Merkel cells

Involve in touch

Langerhans cells

Phagocytic immune cells in the epidermis that engulf bacteria.

Papillary dermis

Superficial dermal layer made of areolar connective tissue; dermal papillae project into epidermis.

Reticular dermis

Deep dermal layer of dense irregular connective tissue; houses glands, hair follicles, nerves.

Merocrine (eccrine) sweat glands

clear, odorless sweat for thermoregulation; ducts open to skin surface.

Apocrine sweat glands

Found in armpit and groin; thicker, milky sweat with pheromones; ducts open into hair follicles.

Sebaceous glands

Oil glands that secrete sebum; associated with hair follicles; can clog and form acne or sebaceous cyst.

Hair

Hair shaft, root and follicle; keratinized structures; shaft extends above skin; hair growth from follicles.

Arrector pili muscle

Smooth muscle attached to hair follicle; contracts to make hair stand (goosebumps) and help conserve heat.

Sebaceous gland

Connect to hair follicle and secrete sebum,which helps lubricate the skin and hair.

Hair follicle

Structure from which hair grows

First-degree burn

Involves only the epidermis; red, painful, dry, no blisters.

Second-degree burn

Partial thickness; involves epidermis and part of the dermis; red, blistered; painful.

Third-degree burn

Full thickness; involves epidermis and dermis; may damage underlying tissues; white or charred; often insensate.

Thin skin

Skin type with four epidermal layers and a thin stratum corneum; covers most of the body.

Thick skin

Skin type with five epidermal layers including stratum lucidum; thick stratum corneum; found on palms and soles.

Melanin

Pigment produced by melanocytes; determines skin color and protects against UV radiation.

Cornification

Process by which keratinocytes fill with keratin and die to form the stratum corneum.

Protection (skin function)

Barrier that protects against pathogens and physical/chemical injury.

Temperature regulation

Sweating and blood flow adjustments help regulate body temperature.

Immune defense (skin)

immune components defend against pathogens.

Sensory reception

Skin contains receptors for touch, pressure, temperature, and pain.

Excretion/Secretion

Sweat and sebum are secretions released by skin glands.