Integumentary System

Flashcards covering key vocabulary and concepts from the integumentary system lecture notes.

Epidermis

The superficial region of the skin consisting of epithelial tissue.

Dermis

The layer of skin that underlies the epidermis, primarily made of fibrous connective tissue.

Hypodermis

Also known as superficial fascia, it is a layer beneath the skin consisting mostly of adipose tissue that absorbs shock and insulates.

Keratinocytes

The most common cell type in the epidermis that produces the fibrous protein keratin.

Melanocytes

Cells in the epidermis that produce the pigment melanin, responsible for skin color.

Dendritic (Langerhans) cells

Immune cells in the epidermis that act as macrophages, key activators of the immune system.

Tactile (Merkel) cells

Sensory touch receptors located in the epidermis.

Stratum corneum

The outermost layer of the epidermis, consisting of dead, flat keratinized cells.

Sebaceous glands

Glands that secrete an oily substance called sebum, which helps to soften hair and skin.

Sweat glands

Glands that produce sweat, contributing to thermoregulation and excretion.

Eccrine sweat glands

The most numerous type of sweat gland, located all over the body, important for thermoregulation.

Apocrine sweat glands

Sweat glands confined to axillary and anogenital areas that secrete a viscous fluid.

Basal Cell Carcinoma

The least malignant and most common skin cancer, originating from stratum basale cells.

Malignant Melanoma

The most dangerous form of skin cancer that arises from melanocytes and is highly metastatic.

Alopecia

A condition characterized by hair thinning or loss, commonly associated with aging.

Striae

Commonly known as stretch marks, these are silvery-white scars resulting from extreme stretching of the skin.

Cyanosis

A bluish skin color indicating low oxygenation of hemoglobin.

Jaundice

A yellowing of the skin and eyes due to liver disorder.

Flexure lines

Dermal folds at or near joints that reflect areas where the skin does not slide easily.

Dermal papillae

Peg-like projections in the dermis that enhance the grip of the epidermis and contribute to fingerprints.

Integument

Another name for the skin, composed of the Epidermis and Dermis.

Epidermis

The superficial region of the skin, made of epithelial tissue.

Dermis

The deeper layer of the skin, made mostly of fibrous connective tissue.

Hypodermis (Superficial fascia)

Not part of the skin, primarily adipose tissue; functions in shock absorption, insulation, and anchoring skin to underlying structures.

Keratinocytes

Epidermal cells that produce keratin, forming 90% of the epidermis.

Melanocytes

Epidermal cells in the stratum basale that produce melanin to protect against UV damage.

Dendritic (Langerhans) cells

Immune system macrophages in the epidermis, engulfing foreign antigens.

Tactile (Merkel) cells

Touch receptors in the epidermis.

Stratum Basale

The deepest epidermal layer, actively mitotic stem cells, contains melanocytes, produces new keratinocytes.

Stratum Spinosum

Epidermal layer several layers thick, cells unified by desmosomes, contains melanosomes and dendritic cells.

Stratum Granulosum

Epidermal layer where cells flatten, organelles disintegrate, keratinization begins, and water-resistant lamellar granules form.

Stratum Lucidum

Translucent epidermal layer present only in thick skin.

Stratum Corneum

The outermost epidermal layer, 20-30 rows of dead, keratinized cells, providing protection and a barrier.

Papillary Layer (Dermis)

Superficial dermal layer of areolar connective tissue containing dermal papillae with capillary loops and touch receptors.

Reticular Layer (Dermis)

Deeper dermal layer (approx. 80% thickness) of dense fibrous connective tissue, providing strength and elasticity.

Flexure Lines

Deep creases in the skin where the dermis is tightly secured to underlying structures, common on joints.

Striae

Stretch marks caused by dermal tears during extreme stretching.

Blisters

Fluid-filled pockets separating layers of skin, formed by acute trauma.

Melanin

Main pigment produced in the skin (reddish-yellow to brownish-black), protects against UV radiation.

Carotene

Yellow to orange pigment accumulating in the stratum corneum and fat layers, significant for vitamin A synthesis.

Hemoglobin

Reddish pigment in oxygenated blood, contributing to a pinkish hue in fair skin.

Cyanosis

Blue skin color indicating low oxygen levels.

Erythema

Redness of skin due to conditions like fever or inflammation.

Pallor

Paleness of skin indicating underlying blood issues or emotional states.

Jaundice

Yellowing of skin indicating liver dysfunction.

Hair

Appendage of skin composed of dead keratinized cells, for insulation and protection.

Nails

Protect and support fingers and toes.

Eccrine (Merocrine) Sweat Glands

Most numerous sweat glands, on palms, soles, forehead; always active; secrete 99% water sweat for thermoregulation.

Apocrine Sweat Glands

Sweat glands in axillary and anogenital areas, active at puberty, ducts into hair follicles, secrete sweat with fatty substances and proteins.

Sebaceous (Oil) Glands

Glands distributed over body (not palms/soles), secrete sebum (oily lipids) into hair follicles, active at puberty, for lubrication and bactericidal properties.

Chemical Barrier

Skin secretions (acid mantle of sweat, dermcidin, sebum, melanin) protecting against microbes and UV radiation.

Physical Barrier

Continuity of epidermal layers (keratinized cells of stratum corneum) providing protection against trauma, pathogens, and water loss.

Biological Barrier

Epidermal dendritic cells and dermal macrophages that engulf antigens and dispose of microbes; DNA absorbs UV radiation.

Temperature Regulation (Integumentary System)

Adjusts blood flow and sweat production via eccrine glands to dissipate or conserve heat.

Sensation (Integumentary System)

Contains receptors for touch, pressure, temperature, and pain.

Metabolic Functions (Integumentary System)

Synthesizes Vitamin D upon sunlight exposure; keratinocyte enzymes activate hormones.

Blood Reservoir (Integumentary System)

Stores approx. 5% of body's total blood volume in the dermal vascular plexus.

Excretion (Integumentary System)

Removes limited nitrogenous wastes (ammonia, urea, uric acid) in sweat.

Basal Cell Carcinoma

Most common, least dangerous skin cancer, arises from stratum basale, rarely metastasizes.

Squamous Cell Carcinoma

Second-most common skin cancer, arises from keratinocytes of stratum spinosum, higher risk of metastasis.

Melanoma

Most dangerous skin cancer, originates from melanocytes, highly metastatic, resistant to chemotherapy.

ABCD Rule for Melanoma Detection

Asymmetry, Border irregularity, Color variation, Diameter greater than 6 mm.

First-Degree Burn

Only epidermal damage, characterized by redness, swelling, and pain.

Second-Degree Burn

Damage to epidermis and upper part of dermis, characterized by redness, swelling, pain, and blisters.

Third-Degree Burn (Full-Thickness)

Involves entire thickness of skin, possibly deeper tissue; appears gray-white, cherry red, or blackened; numb due to nerve destruction; requires skin grafting.

Rule of Nines

Method used to estimate the percentage of total body surface area (TBSA) affected by burns to assess fluid loss and severity.