Integumentary System

Vocabulary flashcards covering the components, layers, cell types, glands, conditions, and pathology of the integumentary system based on Chapter 6 lecture notes.

Integumentary system

The system consisting of skin, hair, nails, sweat glands, and sebaceous (oil) glands.

Integument

A term meaning 'covering'; the skin is the body’s largest and heaviest organ.

Keratin

A protein that provides physical protection and allows the skin to resist trauma and infection.

Thermoregulation

The skin's function of altering blood flow to release or retain heat, along with sweating.

Epidermis

The outermost protective layer of the skin, made of keratinized stratified squamous epithelium.

Dermis

The layer of connective tissue located under the epidermis, composed mainly of collagen, elastic, and reticular fibers.

Hypodermis

The layer below the dermis, mostly composed of adipose fat tissue, which absorbs shock, insulates, and anchors the skin.

Keratinocytes

The great majority of epidermal cells that synthesize keratin to resist abrasion and prevent water loss.

Stem cells

Undifferentiated cells in the stratum basale that continuously divide to give rise to keratinocytes.

Melanocytes

Cells that synthesize the pigment melanin to shield DNA from ultraviolet radiation.

Tactile cells (merkel cells)

Touch receptor cells associated with dermal nerve fibers, abundant in the hands and feet.

Dendritic cells

Phagocytic immune cells that guard against toxins and microbes.

Stratum Basale

The deepest epidermal layer attached to the dermis, containing a single layer of stem cells, keratinocytes, melanocytes, and tactile cells.

Stratum Spinosum

The layer consisting of several rows of living keratinocytes, named for their spiny appearance during histological preparation.

Stratum Granulosum

A layer of 4-6 cell rows where keratinization begins and nuclei and organelles die; all cells above this layer are not alive.

Stratum Lucidum

A thin, translucent band of 2-3 rows of clear, flat, dead keratinocytes found only in thick skin.

Stratum Corneum

The outermost layer of dead, scaly, keratinized cells (20-30 layers thick) that helps resist abrasion and water loss.

Papillary layer

The thin zone of areolar tissue in the dermis that allows for leukocyte mobility and contains dermal papillae.

Dermal papillae

Folds in the papillary layer of the dermis that create fingerprints.

Reticular layer

The deeper, thicker layer (~80%) of the dermis composed of dense irregular connective tissue.

Eczema

An allergic reaction resulting in dry, itchy patches of skin caused by overactive dendritic immune cells.

Melanin

The primary pigment contributor to skin color; differences in color are due to the kind and amount made and retained.

Carotene

A yellow to orange pigment taken up by food (fruits and vegetables like carrots).

Hemoglobin

A pigment that provides a pinkish hue to fair skin when melanin levels are low.

Cyanosis

A blue skin color caused by low oxygenation of hemoglobin.

Pallor

A blanching or pale color associated with anemia, low blood pressure, fear, or anger.

Erythema

Redness of the skin caused by fever, hypertension, inflammation, or allergy.

Jaundice

A yellow cast to the skin indicating a liver disorder.

Vitiligo

A chronic autoimmune disorder that causes patches of skin to lose pigment.

Eccrine glands

The most numerous sweat glands (3-4 million), abundant on palms, soles, and forehead, functioning in thermoregulation.

Apocrine glands

Sweat glands in armpits and genitals that produce milky, fatty sweat; they are inactive until puberty.

Sebaceous glands

Glands that produce sebum (oil) into hair follicles to keep skin and hair from becoming dry, brittle, and cracked.

Ceruminous glands

Modified apocrine glands in the external ear canal that produce cerumen (earwax).

Basal cell carcinoma

The most common and least dangerous skin cancer, forming from cells in the stratum basale.

Squamous cell carcinoma

Skin cancer arising from keratinocytes of the stratum spinosum; it may metastasize to lymph nodes.

Malignant melanoma

A highly metastatic and chemotherapy-resistant skin cancer arising from melanocytes, often identified by the ABCDE rule.

First-degree burn

A burn involving only the epidermis, characterized by redness, slight edema, and pain.

Second-degree burn

A burn involving the epidermis and part of the dermis, often appearing blistered and painful.

Third-degree burn

A full-thickness burn involving the entire dermis and deeper tissues, requiring fluid replacement and often skin grafts.