The Integumentary System (PHC411)

The outermost layer of skin, composed of stratified squamous epithelium.

The most abundant epidermal cells, producing keratin for protection.

Epidermal cells that produce melanin, protecting skin from UV radiation.

Immune cells in the epidermis that help fight pathogens.

The deepest layer of the epidermis, containing stem cells and melanocytes.

A layer of the epidermis, characterized by keratin filaments and Langerhans cells.

A procedure to replace damaged skin.

The process by which the skin repairs itself following injury.

A medical condition affecting the skin.

Fingerprints develop where the stratum basale meets the dermal papillae, creating unique ridge patterns.

Fingerprints are unique to each individual and do not change.

The subcutaneous layer stabilizes skin position relative to underlying tissues.

Substances absorb through the skin using oils/lipids. Drugs move slowly across.

Melanin, produced by melanocytes, is the primary determinant of skin color.

Eumelanin (brown/black) and pheomelanin (yellow/red) are types of melanin.

Melanocytes produce melanin, protecting skin from UV rays and neutralizing free radicals.

UV exposure increases melanin production, darkening the skin.

People have the same number of melanocytes but different amounts of melanin, due to varying UV exposure.

3-5 layers of flat keratinocytes undergoing apoptosis, containing keratohyalin and lamellar granules.

Found only in thick skin (fingertips, palms, soles), this layer consists of flattened, clear, dead keratinocytes.

Many layers of dead, scaly, keratinized cells forming a protective barrier against abrasion, penetration, and water loss.

Process of replacing viable cells with keratin protein as cells move to the surface of the skin.

Increased keratin production due to constant friction, resulting in skin thickening.

Chronic skin disorder causing rapid keratinocyte division and movement to the surface.

Layer of skin below the epidermis, composed of dense irregular connective tissue containing collagen and elastic fibers. Contains blood vessels, nerves, glands, and hair follicles.

Superficial layer of the dermis, composed of areolar connective tissue with dermal papillae increasing surface area.

Deeper layer of the dermis, composed of dense irregular connective tissue, and containing hair follicles, glands, and a lot of collagen and elastic fiber.

The part of the hair above the skin's surface.

The structure that encloses the hair root and is responsible for hair growth.

The part of the hair below the skin's surface, extending into the dermis

The core of the hair, made of loosely arranged cells and air spaces.

The majority of the hair's structure, made of layers of keratinized cells.

The outermost layer of the hair, composed of overlapping scaly cells that point outwards.

Hair grows in cycles of growth, regression, and resting, with hair cells actively dividing, stopping, and resting for new growth.

Fine, nonpigmented, downy hairs that cover a fetus's body.

Fine, short hairs barely visible, growing on most parts of the body.

Longer, coarse, heavily pigmented hairs that grow on specific body parts like the head, armpit and pubic region.

Determined by the amount and type of melanin produced by melanocytes in the hair bulb.

Connective tissue and blood vessels at the base of the hair follicle, nourishing the growing hair follicle.

Cells in the hair bulb that produce new hair.

Gray hair occurs due to a decrease in melanin production.

Thinning of hair or baldness.

Excessive hair growth in areas not usually hairy due to hormone imbalances from tumors.

Keratinized epidermal cells over fingers/toes forming the nail plate.

Nail cells divide and grow approximately 1mm per week, but growth is slower in toenails.

Structure beneath nail free edge attaching the nail to the fingertip.

Stratum corneum at the proximal nail border.

Cells dividing to produce new nail cells, determining nail growth.

Sebum production, preventing dryness and inhibiting bacteria.

Sebum is made of triglycerides, cholesterol, proteins, and inorganic salts.

Most numerous sweat glands, producing watery perspiration for thermoregulation.

Produce thicker, milky sweat for body odor, activated at puberty.

Modified sweat glands in ear canal producing earwax.

Sweating releases heat from the body by evaporation at the skin surface, cooling the body down.

Expanding or constricting blood vessels near the skin surface moves heat between the body's core and the environment.

The skin holds a significant portion of the body's blood, acting as a reserve when needed.

Hard protein that forms a barrier, protecting the skin from microbes, abrasion, heat, chemicals.

Skin releases lipids to prevent water loss, keeping it hydrated.

Oil produced by the skin that prevents drying and kills some bacteria.

Skin's acidity inhibits the growth of some microbes.

Pigment that shields the skin from UV radiation.

Epidermal cells alert the immune system to pathogens, and the dermis fights infection.

Skin detects various sensations like touch, pressure, vibration, warmth, and coolness.

Skin eliminates substances (water, heat, salts, etc.) and absorbs others (fat-soluble vitamins).

Skin produces a Vitamin D precursor that needs sunlight and further processing by the kidneys and liver for its active form.

Repair of superficial wounds that affect only the epidermis, usually with full restoration of function.

Repair of wounds that extend to the dermis and subcutaneous layer, often leaving scars.