Chapter 06 - Integumentary System Flashcards

Vocabulary practice flashcards covering Chapter 06: Integumentary System from Hole's Human Anatomy & Physiology.

Epidermis

The outer layer of skin composed of stratified squamous epithelium that lacks blood vessels.

Dermis

The inner major layer of skin composed of connective tissue containing collagenous and elastic fibers, muscle, blood, and nervous tissue.

Subcutaneous Layer

An insulating layer beneath the dermis composed of areolar and adipose connective tissue; also called the hypodermis.

Keratinization

The process of hardening, dehydration, and keratin accumulation that occurs in epidermal cells as they migrate outward.

Stratum Corneum

The outermost epidermal layer consisting of many layers of keratinized, dead epithelial cells that are flattened and non-nucleated.

Stratum Lucidum

A clear layer of the epidermis found only in thick skin on the palms and soles, located between the stratum corneum and stratum granulosum.

Stratum Granulosum

An epidermal layer beneath the stratum corneum containing three to five layers of flattened granular cells with shrunken keratin fibers and shriveled nuclei.

Stratum Spinosum

An epidermal layer beneath the stratum granulosum composed of many layers of cells with central, large, oval nuclei and developing keratin fibers.

Stratum Basale

The deepest layer of the epidermis consisting of a single row of cuboidal or columnar cells that divide and grow.

Dendritic (Langerhans) Cells

Phagocytic cells located in the stratum spinosum that protect the skin and underlying tissues from infection.

Tactile (Merkel) Cells

Sensory receptors located in the stratum basale that combine with sensory nerve endings to form tactile discs for light touch perception.

Melanocytes

Cells located in the stratum basale that produce melanin to absorb UV light and protect skin cells from radiation damage.

Eumelanin

A brownish-black melanin pigment found in the epidermis.

Pheomelanin

A reddish-yellow melanin pigment found in specific areas such as the lips.

Albinism

An inherited mutation in melanin genes resulting in nonpigmented skin due to a lack of melanin production.

Melanomas

Skin cancers arising from melanocytes that account for $4\%$ of skin cancers but cause $80\%$ of skin cancer deaths.

Dermal Papillae

Projections of the dermis extending between epidermal ridges that form fingerprints.

Lamellated (Pacinian) Corpuscles

Sensory receptors located in the dermis that respond to pressure.

Tactile (Meissner's) Corpuscles

Sensory receptors located in the dermis that detect light touch.

Papillary Layer

The superficial, thinner layer of the dermis composed of areolar connective tissue containing dermal papillae.

Reticular Layer

The deeper, thicker layer of the dermis composed of dense irregular connective tissue.

Nail Structure

Protective covering on the ends of fingers and toes consisting of a nail plate, nail bed, nail matrix, lunula, and cuticle.

Nail Matrix

The active growth region of a nail located at the proximal end of the nail bed.

Lunula

The pale, half-moon-shaped region at the base of the nail plate overlying the nail matrix.

Hair Follicle

A tube-like depression of epidermal cells extending into the dermis or subcutaneous layer from which a hair grows.

Arrector Pili Muscle

Smooth muscle attached to a hair follicle that contracts in response to cold or fear, causing goosebumps.

Androgenic Alopecia

Pattern baldness associated with lowered levels of testosterone in men or estrogen in women where top-of-head hair is lost.

Alopecia Areata

An autoimmune disorder where antibodies attack hair follicles, resulting in hair loss.

Sebaceous Glands

Holocrine glands associated with hair follicles that produce sebum to keep hair and skin soft and waterproof.

Eccrine (Merocrine) Sweat Glands

Abundant sudoriferous glands that secrete odorless, water-based sweat through pores to lower body temperature.

Apocrine Sweat Glands

Sudoriferous glands in the axillary and groin regions that open into hair follicles and secrete in response to pain, fear, emotional upset, or sexual arousal.

Ceruminous Glands

Modified sweat glands located in the external acoustic meatus that secrete ear wax.

Mammary Glands

Modified sweat glands located in the breasts that secrete milk.

Radiation

The primary method of heat loss where infrared heat rays travel from warmer skin to a cooler environment.

Conduction

The transfer of heat from warmer skin directly into cooler objects in physical contact with it.

Convection

The transfer of body heat away from the skin into surrounding, circulating air currents.

Evaporation

Heat loss occurring as liquid sweat changes into gas on the skin surface, carrying heat away.

Body Temperature Regulation

Homeostatic feedback loop controlled by the hypothalamus set to maintain deep body temperature near $37^\natural\text{C}$ ($98.6^\natural\text{F}$).

Hyperthermia

An abnormally high body temperature occurring when heat gain exceeds heat loss.

Hypothermia

An abnormally low body temperature resulting from prolonged exposure to cold or illness.

Inflammation

A normal physiological response to injury or stress where dilated blood vessels cause tissues to become reddened, swollen, warm, and painful.

Healing of a Wound

The process where blood clots, scabs, fibroblasts, collagen fibers, and regenerated epithelial cells repair tissue damage.

Superficial Partial-Thickness Burn

A first-degree burn injuring only the epidermis that heals in days to weeks without scarring.

Deep Partial-Thickness Burn

A second-degree burn destroying the epidermis and some dermis, often forming blisters.

Full-Thickness Burn

A third-degree burn destroying the epidermis, dermis, and accessory structures, frequently requiring skin grafting.

Categories of Burns

Classification of burn injuries into superficial partial-thickness, deep partial-thickness, and full-thickness based on tissue depth damage.

Rule of Nines

A clinical method dividing body surface area into regions of $9\%$ or multiples of $9\%$ to estimate burn area for fluid replacement planning.