Module 6 - Integumentary System

Cutaneous Membrane

Epithelial membrane commonly known as the skin consisting of an outer epithelial layer and inner connective tissue layer

Epidermis

Outermost layer of the skin composed entirely of avascular epithelial cells

Dermis

Connective tissue portion of the skin containing blood vessels nerve endings and glands

Stratum

Individual thin layer of epithelial cells within the epidermis

Stratum Basale

Deepest epidermal layer where active cell division continuously produces new skin cells

Keratin

Tough protective protein that thickens skin cells and makes the epidermal surface water-resistant

Stratum Corneum

Outermost epidermal layer consisting of flat dead keratinized cells that continuously flake off

Exfoliation

Natural sloughing or shedding off of dead skin cells from the stratum corneum

Melanin

Dark pigment produced by melanocytes that determines skin color and protects against ultraviolet radiation

Melanocyte

Specialized epidermal cell that synthesizes the protective pigment melanin

Dermal Papillae

Finger-like projections of the dermis extending upward into the epidermis that form friction ridges like fingerprints

Subcutaneous Layer or Hypodermis

Underlying connective tissue layer consisting of areolar and adipose tissue that anchors the skin to underlying muscles

Sebaceous Gland

Exocrine gland that secretes sebum to lubricate and waterproof the skin and hair

Sebum

Oily secretion produced by sebaceous glands that prevents drying of the skin

Vernix Caseosa

Cheeselike sebaceous coating covering the skin of a newborn to protect it in the womb

Meibomian Gland

Modified sebaceous gland along the eyelids that secretes oil to prevent evaporation of tear fluid

Sweat Gland or Sudoriferous Gland

Exocrine gland that secretes sweat to regulate body temperature or respond to stress

Eccrine Gland

Primary temperature-regulating sweat gland that secretes watery fluid directly onto the skin surface

Apocrine Gland

Specialized sweat gland active at puberty located in axillary and anogenital areas that secretes organic substances broken down by bacteria to produce body odor

Cerumen

Waxy substance commonly called earwax produced by modified ceruminous glands in the ear canal

Mammary Gland

Modified sweat gland in the breast tissue that produces milk for infant nutrition

Hair Follicle

Sheath of epithelial and connective tissue enclosing the hair root from which a hair develops

Arrector Pili

Smooth muscle attached to a hair follicle that contracts to elevate the hair and produce goosebumps

Nail Matrix

Growth region at the proximal end of the nail where new keratinized cells continuously develop

Lunula

Pale half-moon shaped region at the proximal end of the nail plate covering the thick growth area

Cuticle

Extension of the epidermal stratum corneum that seals the space between the skin and proximal nail plate

Integumentary System

Organ system comprising the skin and its accessory structures that protects the body and helps maintain homeostasis

Dehydration Protection

Prevention of excessive fluid loss through keratin waterproofing and oily sebum barrier formation

Vasoconstriction

Narrowing of skin blood vessels in cold conditions to reduce blood flow to the surface and conserve body heat

Vasodilation

Widening of skin blood vessels in warm conditions to bring blood to the surface and radiate excess body heat

Perspiration Evaporation

Thermal cooling mechanism where heat is drawn from the skin as sweat turns into vapor

Skin Receptors

Specialized nerve endings within the skin that detect pain temperature touch and deep pressure

Transdermal Absorption

Route of administration where limited amounts of medications are absorbed directly through the skin surface

Cutaneous Excretion

Minor elimination of water electrolytes and nitrogenous wastes through sweat production

Vitamin D Synthesis

Production of essential vitamin D within skin cells triggered by exposure to ultraviolet solar radiation

Skin Discoloration

Any distinct change from normal skin color caused by alterations in pigments blood flow or disease states

Melanin

Primary pigment of the skin produced by melanocytes that protects against ultraviolet radiation

Albinism

Hereditary condition characterized by a total lack of melanin pigment in the skin hair and eyes

Vitiligo

Skin disorder characterized by patchy loss of pigment due to localized destruction or inactivity of melanocytes

Hemoglobin

Oxygen-carrying red blood cell pigment that gives a pinkish or red hue to well-oxygenated skin

Pallor

Unnatural paleness of the skin often caused by reduced blood flow or decreased hemoglobin levels

Cyanosis

Bluish discoloration of the skin and mucous membranes caused by insufficient oxygen in circulating blood

Carotenemia

Harmless yellowish skin discoloration caused by excessive accumulation of carotene from dietary plant intake

Jaundice

Yellowish discoloration of the skin and sclera caused by elevated levels of bilirubin in the blood

Bilirubin

Yellow bile pigment produced during the breakdown of hemoglobin that accumulates in tissues during liver dysfunction or biliary obstruction

Neonatal Jaundice

Common newborn condition where an immature liver cannot yet efficiently process and excrete bilirubin

Inflammation

Initial response to tissue injury where blood flow increases to bring growth factors immune cells and repair agents to the site

Fibroblast

Connective tissue cell that manufactures collagen and other structural materials to close wound gaps

Scar or Cicatrix

Fibrous tissue formed by fibroblasts that replaces normal tissue during the healing of deep wounds

Keloid

Marked overgrowth of scar tissue extending beyond the original wound boundary following skin trauma

Scab

Crust formed over a dry wound that provides protection but can slow healing and increase scar formation

Moist Wound Healing

Clinical approach of keeping a wound moist to speed cell migration retain growth factors and reduce scarring

Wound Healing Factors

Variables such as nutrition blood supply infection and age that determine the speed and effectiveness of skin repair

Parchment Skin

Age-related thinning of the dermis accompanied by loss of collagen elastic fibers and subcutaneous fat

Liver Spots or Solar Lentigines

Localized areas of hyperpigmentation on sun-exposed skin caused by altered melanin distribution in aging

Hair Graying and Thinning

Age-related changes driven by decreased melanin production reduced hair replacement and lower sebum output

Impaired Thermoregulation

Reduced ability to adapt to temperature extremes in older adults due to fewer sweat glands and decreased subcutaneous fat

Delayed Skin Repair

Slower wound healing and higher infection risk in elderly individuals resulting from reduced dermal blood flow and cell division

Photoaging and Skin Cancer Risk

Structural degradation and genetic mutations in skin cells caused by cumulative ultraviolet radiation exposure

Dermatosis

General term for any abnormal skin condition or disease

Lesion

Any localized damage or wound to body tissue

Rash or Eruption

Surface skin lesion or rash that appears suddenly

Erythema

Redness of the skin caused by capillary congestion and inflammation

Macule

Flat discolored spot on the skin neither raised nor depressed under 1 cm in size like a freckle

Patch

Flat discolored area of skin larger than 1 cm in size

Papule

Firm raised skin lesion less than 1 cm in size such as a pimple

Nodule

Solid raised round skin lesion larger than 1 cm in size

Vesicle

Small fluid-filled blister on the skin less than 5 mm in size

Bulla

Large fluid-filled blister on the skin greater than 5 mm in size

Pustule

Small pus-filled skin lesion less than 1 cm in size often resulting from infected vesicles

Excoriation

Superficial scratch or scrape into the skin surface

Laceration

Rough jagged wound made by tearing of the skin

Ulcer

Open sore associated with disintegration and necrosis of tissue

Fissure

Crack or linear groove in the skin extending into the dermis

Pressure Ulcers or Decubitus Ulcers

Skin lesions caused by prolonged pressure over bony prominences that interrupts blood circulation and leads to tissue necrosis

Pressure Ulcer Risk Factors

Clinical factors including immobility malnutrition excess moisture and impaired sensation that increase susceptibility to bedsore formation

Superficial Burn or First Degree Burn

Burn involving only the epidermis characterized by redness dryness minimal pain and blanching upon pressure

Superficial Partial Thickness Burn

Second degree burn involving the epidermis and upper dermis characterized by redness painful blistering and weeping tissue

Deep Partial Thickness Burn

Second degree burn extending into the deep dermis causing severe blistering variable pain from nerve damage and potential sweat gland destruction

Full Thickness Burn or Third Degree Burn

Severe burn destroying the entire epidermis dermis and underlying subcutaneous tissue causing charred or pale dry skin requiring skin grafts

Rule of Nines

Diagnostic method for estimating total burned body surface area by assigning percentages in multiples of nine to body regions

Basal Cell Carcinoma

Most common form of epidermal skin cancer that rarely metastasizes and typically appears on sun-exposed areas

Squamous Cell Carcinoma

Epidermal skin cancer with a higher likelihood of metastasizing than basal cell carcinoma

Melanoma

Malignant skin cancer originating in melanocytes that is highly invasive and prone to early metastasis

Cellulitis

Spreading bacterial infection involving the deeper dermis and subcutaneous tissues

Impetigo

Contagious bacterial skin infection characterized by superficial pustules and crusting lesions

Herpes Simplex Virus

Viral infection causing fluid-filled vesicles known as cold sores or fever blisters on the skin or mucous membranes

Shingles or Herpes Zoster

Reactivation of the chickenpox virus causing painful vesicular lesions along specific nerve pathways

Verruca or Wart

Benign epidermal growth caused by viral infection of skin cells

Tinea or Ringworm

Superficial fungal skin infection causing red ring-shaped lesions on various parts of the body

Dermatitis

General term for inflammation of the skin resulting from various allergic or irritant triggers

Urticaria or Hives

Acute allergic skin reaction characterized by temporary raised red itchy welts

Eczema or Atopic Dermatitis

Inflammatory skin condition marked by redness intense itching crusting and scaling of the skin

Pemphigus

Autoimmune disease of the skin characterized by widespread blistering and skin erosion

Systemic Sclerosis or Scleroderma

Autoimmune disorder involving collagen overproduction causing severe thickening and tightening of the skin

Raynaud Phenomenon

Episodic constriction of blood vessels in the fingers and toes in response to cold or stress often seen in scleroderma

Psoriasis

Chronic autoimmune skin condition characterized by red patches covered with silvery scales

Acne Vulgaris

Inflammatory disorder of the sebaceous glands and hair follicles marked by comedones pimples and cysts

Comedo

Plug of sebum and keratin inside a hair follicle forming a blackhead when open or a whitehead when closed

Alopecia

Loss or absence of hair from skin areas where it normally grows