Skin Integumentary System Chapter 12 Related Combining Forms
Skin Integumentary Systemchapter 12related Combining Formsstructurere
Skin: Integumentary System Chapter 12 Related Combining Forms Structure Related Combining Forms Skin cutane/o, dermat/o, derm/o Sebaceous glands seb/o Sweat glands hidr/o Hair pil/i, pil/o Nails onych/o, ungu/o Integumentary System Consists of skin and its related structures (sebaceous glands, sweat glands, hair, and nails) Average adult has two square yards of skin, making it the largest body organ Functions of Skin Keeps the body waterproof, hence preventing fluid loss When intact, skin blocks the entrance of pathogens Contains receptors for the sense of touch Synthesizes vitamin D from the sun 4 Functions of Related Structures Sebaceous glands Secrete sebum that lubricates skin and discourages growth of bacteria on skin Sweat glands Assist with body water content and temperature regulation Excretion of small amounts of metabolic wastes Functions of Related Structures Hair Helps control the loss of body heat Nails Protect dorsal surface of last bone of each toe and finger Structures of Skin and Its Related Structures Skin Specialized tissues Three layers Epidermis Dermis Subcutaneous (cutane: skin; -ous: pertaining to) Structures of Skin and Its Related Structures Epidermis (epi-: above or upon; derm: skin; -is: noun ending) Outermost layer of skin Made of specialized epithelial tissues Contains no blood vessels or connective tissue Depends on the lower layers for nourishment Epidermis Epithelial tissues Form protective covering for internal and external surfaces of the body Squamous epithelial tissue Forms upper layer of epidermis Flat, scaly cells continuously shed Epidermis Basal layer Lowest layer of epidermis Site of new cell production When cells reach surface, they die and become filled with keratin Keratin Fibrous, water-repellent protein Soft keratin: component of epidermis Hard keratin: found in hair and nails Epidermis Melanocytes Special cells in basal cell layer Produce and contain dark brown to black pigment known as melanin Melanin Pigment that determines color of skin, produces freckles and age spots Protects skin from some of the harmful UV rays Dermis Directly below epidermis Contains connective tissue, blood and lymph vessels, nerve fibers, hair follicles, sebaceous glands, and sweat glands Sensory nerve endings Sensory receptors for touch, temperature, pain, and pressure Tissues Within Dermis Collagen Tough flexible fibrous protein found in skin, bones, cartilage, tendons, and ligaments Mast cells Found in connective tissue of dermis Respond to injury, infection, or allergy by producing and releasing heparin (anticoagulant) and histamine (causes allergic response) Subcutaneous Layer Located below the layers of skin Connects skin to the surface muscles Made of loose connective tissue and adipose tissue Lipocytes manufacture and store large quantities of fat (lip/o: fat; -cytes: cells) Sebaceous Glands Located in dermis Closely associated with hair follicles Sebum Oily substance released through ducts opening into hair follicles Lubricates skin Acidic, thus discourages growth of bacteria on skin Sebaceous Glands Mammary glands Produce milk Also part of the reproductive system Sweat Glands Sudoriferous glands Located on almost all body surfaces Two types Apocrine Found at hair follicles Eccrine Open onto skin Most numerous in palms, soles, and forehead Sweat Glands Pores Opening on the surface of skin Act as ducts of the sweat glands Perspiration Secreted by sweat glands 99% water plus salt and metabolic waste Evaporation of sweat cools the body Sweat Glands Hidrosis Production and excretion of perspiration Hair Composed of dead protein cells filled with hard keratin Color of hair determined by melanin Hair follicles Sacs holding the root of hair fibers Arrector pili Muscle fibers attached to hair follicles that cause hair to stand erect, reducing heat loss Nails Unguis (fingernail or toenail) Keratin plate protecting dorsal surface of the last bone of each finger and toe Nail body Translucent Molded to surface of underlying tissues Make of hard, keratinized plates of epidermal cells Nails Nails Nail bed Joins nail body to underlying connective tissue Nourishes the nail Blood vessels provide pink color Free edge Portion of nail not attached to the nail bed Extends beyond tip of the finger or toe Nails Lunula Half-moon-shaped region at nail root Site of new keratin cell formation (lun: moon; -ula: little) Cuticle Epidermis attached to the surface of nail Nail root Fastens nail to finger/toe Medical Specialties Related to Integumentary System Dermatologist Specializes in diagnosing/treating disorders of the skin (dermat: skin; -ologist: specialist) Plastic surgeon Specializes in surgical restoration or reconstruction of body structures (-plasty: surgical repair) Medical Specialties Related to Integumentary System Cosmetic surgeon Plastic surgeon who performs operations for aesthetic rather than medical reasons Pathology of Integumentary System Sebaceous Glands Acne vulgaris Chronic inflammatory disease caused by the overproduction of sebum around the hair shaft Comedo Noninfected lesion composed of sebum and keratin in hair follicle Closed comedo: whitehead Open comedo: blackhead Sebaceous Glands Epidermoid cyst Closed sac just under the skin Contains fatty material Seborrhea Overproduction of sebum (seb/o: sebum; -rrhea: flow or discharge) Sebaceous Glands Seborrheic dermatitis Inflammation causing scaling/itching of upper layers of skin/scalp Seborrheic keratosis Benign skin growth having a waxy appearance Varied colors Common in elderly Sweat Glands Anhidrosis Condition of lacking sweat in response to heat (an-: without; hidr: sweat; -osis: abnormal condition) Diaphoresis Profuse sweating (dia-: through or complete; phor: movement; -esis: abnormal condition) Heat rash Itchy rash related to the blockage of sweat glands by bacteria and dead cells Sweat Glands Hyperhidrosis Excessive sweating in one area or over the whole body (hyper-: excessive; hidr: sweat; -osis: abnormal condition) Sleep hyperhidrosis Hyperhidrosis during sleep Hair Folliculitis Inflammation of hair follicles (follicul: hair follicle; -itis: inflammation) Trichomycosis axillaris Superficial bacterial infection of hair shafts in areas with extensive sweat glands, such as armpits (trich/o: hair; myc: fungus; -osis: abnormal condition; axill: armpit; -ary: pertaining to) Excessive Hairiness Hirsutism Excessive body and facial hair in women, usually occurring in a male pattern (hirsut: hairy; -ism: condition) Abnormal Hair Loss Alopecia Partial or complete loss of hair (alopec: baldness; -ia: condition) Alopecia areata Autoimmune disorder attacking hair follicles Occurs in patches on scalp or elsewhere on body Abnormal Hair Loss Alopecia totalis Loss of all hair on the scalp Alopecia universalis Total loss of hair on all parts of the body Androgenic alopecia Hair loss due to hormonal changes Occurs in males and females Nails Clubbing Abnormal curving of nails Often accompanied by enlargement of fingertips May be hereditary May be due to changes associated with oxygen deficiencies related to coronary or pulmonary disease Nails Koilonychia Outer surface of nail is concave Often indicates iron-deficiency anemia (koil: hollow or concave; onych: fingernail or toenail; -ia: condition) Onychia Inflammation of matrix of nail May result in the loss of nail Nails Onychocryptosis Edges of toenail curve inward and cut into the skin (onych/o: fingernail or toenail; crypt: hidden; -osis: abnormal condition) Onychomycosis Fungal infection of nail (myc: fungus) Paronychia Infection of skin fold around a nail (par-: near) Skin Pigmentation Acanthosis nigricans Development of dark wart-like patches on one or more areas of skin Age spots Discoloration caused by sun exposure Albinism Genetic condition characterized by lack of pigment in skin, hair, and irises of eyes (albin: white) Skin Pigmentation Chloasma Brownish spots on face May occur during pregnancy, and disappear after delivery of infant Vitiligo Irregular patches of white skin related to destruction of melanocytes Bleeding into Skin Contusion Injury to underlying tissues without breaking the skin Discoloration caused by accumulation of blood within the skin (contus: bruise; -ion: condition) Bleeding into Skin Ecchymosis Large, irregular purplish discoloration due to bleeding under the skin (ecchym: pouring out of juice; -osis: abnormal condition) Purpura Multiple purple discoloration on skin due to bleeding underneath the skin (purpur: purple; -a: noun ending) Bleeding into Skin Petechiae Small, pinpoint hemorrhages less than 2 mm in diameter Hematoma Usually due to injury Swelling of clotted blood trapped in tissues Blood is reabsorbed (hemat: blood; -oma: tumor) Surface Lesions Crust Collection of dried serum and cellular debris Erosion Wearing away of a surface Macule Flat, discolored spot less than 1 cm in diameter Surface Lesions Surface Lesions Nodule Solid, raised skin lesion larger than 0.5 cm in diameter Papule Raised, red lesion less than 0.5 cm in diameter Does not contain pus Surface Lesions Plaque Scaly, solid raised area of closely spaced papules Scales Flakes or dry patches of excess dead epidermal cells Some shedding is normal Excessive shedding associated with the skin disorders Surface Lesions Verrucae Small, hard skin lesions caused by human papillomavirus Also known as warts Wheal Small, itchy bump May be due to an allergic reaction Fluid-Filled Lesions Abscess Closed pocket containing pus Due to bacterial infection Purulent Producing or containing pus Exudate Fluid leaking out of an infected wound Fluid-Filled Lesions Cyst Abnormal sac containing fluid, or semisolid material Pustule Small, circumscribed lesion containing pus Contained within a limited area Fluid-Filled Lesions Fluid-Filled Lesions Vesicle Blister, less than 0.5 cm in diameter Contains watery fluid Bulla Large blister more than 0.5 cm in diameter Lesions Through Skin Abrasion Superficial layers are scraped away Fissure Crack-like break in the skin Laceration Torn or jagged wound Lesions Through Skin Lesions Through Skin Pressure sore Open ulcerated wound caused by the prolonged pressure on an area of the skin Needlestick injury Accidental puncture wound caused by hypodermic needle Ulcer Open lesion resulting in tissue loss around the edges Birthmarks Pigmented birthmarks Also known as moles or café-au-lait spots Vascular birthmarks Caused by blood vessels close to the skin's surface Birthmarks Capillary hemangioma Soft, raised, pink or red vascular birthmark Benign tissue mass (hem: blood; angi: blood or lymph vessels; -oma: tumor) Port-wine stain Flat vascular birthmark made up of dilated blood capillaries Creates reddish-purple discoloration Dermatitis Inflammation of the skin Contact dermatitis Localized allergic response (dermat: skin; -itis: inflammation) Eczema Recurring dermatitis characterized by redness, itching, and dryness Dermatitis Exfoliative dermatitis Widespread scaling of the skin Pruritus Itching associated with the most forms of dermatitis (prurit: itching) Erythema Redness of skin due to capillary dilation (erythem: flushed; -a: noun ending) Erythema infectiosum Mildly contagious viral infection common in children Also known as fifth disease Erythema Erythema multiforme Generalized allergic reaction to illness, infection, or medication Erythema pernio Purple-red inflammation occurring when small blood vessels below the skin are damaged Erythema Erythroderma Abnormal redness of entire skin surface (erythr/o: red; -derma: skin) Exanthem Widespread rash Hand, foot, and mouth disease Mild viral infection common in children under 5 years of age Sores in mouth/throat; rash on hands/feet General Skin Conditions Dermatosis Denotes skin lesion or eruption of any type not associated with inflammation Ichthyosis Hereditary disorders characterized by dry, thickened, scaly skin (ichthy: dry or scaly; -osis: abnormal condition) General Skin Conditions Lipedema Characterized by accumulation of fat and fluid in tissues under the skin of hips and legs (lip: fat; -edema: swelling) Systemic lupus erythematosus Autoimmune disorder characterized by red, scaly rash on face/upper trunk Psoriasis Occurrence of red papules with silvery scales General Skin Conditions Roseacea Tiny red pimples and broken blood vessels Commonly seen in adults 30–60 years of age Rhinophyma Hyperplasia of tissues of nose Usually seen in older men (rhin/o: nose; -phyma: growth) General Skin Conditions Scleroderma Autoimmune disorder in which connective tissues become thickened and hardened (scler/o: hard; -derma: skin) Urticaria Itchy wheals due to allergic reaction (urtic: rash; -aria: connected with) General Skin Conditions Xeroderma Excessively dry skin (xer/o: dry; -derma: skin) Bacterial Skin Infections Carbuncle Cluster of furuncles Cellulitis Acute bacterial infection within connective tissues Characterized by malaise, swelling, warmth, and red streaks Bacterial Skin Infections Furuncles Large, tender, swollen areas caused by staphylococcal infection around hair follicles or sebaceous glands Gangrene Death of tissue, followed by bacterial invasion, which may also enter bloodstream Commonly due to the loss of circulation to the affected tissues Bacterial Skin Infections Impetigo Highly contagious bacterial skin infection Common in children Necrotizing fasciitis Caused by Group A strep that enters the body through a skin wound Bacterial Skin Infections Pyoderma Acute, pus-forming bacterial skin infection (py/o: pus; -derma: skin) Fungal Skin Infections Mycosis Abnormal condition caused by fungus (myc: fungus; -osis: abnormal condition) Tinea Fungal infection on skin, hair, or nails Known as ringworm Parasitic Skin Infestations Pediculosis Infestation with lice (pedicul: lice; -osis: abnormal condition) Scabies Skin infection caused by itch mites Skin Growths Callus Thickening of the part of the skin caused by repeated rubbing Cicatrix Normal scar Granulation tissue Forms during healing of a wound Skin Growths Granuloma Small swelling of granulation tissue May result from inflammation, injury, infection (granul: granular; -oma: tumor) Keloid Thickened scar expanding beyond the boundaries of original incision (kel: growth or tumor; -oid: resembling) Skin Growths Keratosis Overgrowth and thickening of the skin (kerat: hard or horny) Lipoma Benign fatty tumor located between the skin and muscle layer Nevus Small, dark skin growth developing from melanocytes Skin Growths Dysplastic nevi Atypical moles May develop into skin cancer Papilloma Benign wart-like growth on epithelial tissue or elsewhere in the body (papill: resembling a nipple; -oma: tumor) Skin Growths Polyp Mushroom-like growth from the surface of mucous membrane Skin tags Flesh-colored polyps hanging from the body by fine stalks Benign Tend to enlarge with age Skin Cancers Malignant growth on skin Three types Basal cell carcinoma Squamous cell carcinoma Melanoma Skin Cancers Actinic keratosis Precancerous skin growth occurring on sun-damaged skin Lack of treatment may lead to cancer Basal cell carcinoma Malignant tumor of basal cell layer of epidermis Rarely spreads Skin Cancers Squamous cell carcinoma Malignant tumor of squamous cells of epithelium Can spread quickly to other body systems Malignant melanoma Occurs in melanocytes Initial symptoms are change in the size, shape, or color of a mole (melan: black; -oma: tumor) Burns Injury caused by heat, flame, electricity, sun, chemicals, or radiation Severity described according to the percentage of the total body skin surface affected or by depth or layer of skin involved Diagnostic Procedures of Integumentary System Biopsy Removal of small piece of living tissue for confirmation of diagnosis (bi: pertaining to life; -opsy: view of) Exfoliative cytology Cells are scraped from tissue for microscopic examination Treatment Procedures of Integumentary System Preventive measures Sunscreen Blocks harmful ultraviolet B (UVB) rays or ultraviolet A (UVA) rays Measured in terms of strength of sun protection factor (SPF) Burn Treatment Depends on degree of burn, and percentage of the body surface involved Burn centers provide pain relief, debridement, dermoplasty, IV fluids and nutritional supplements, antibiotics, cosmetic reconstruction, and rehabilitation Tissue Removal Cauterization Destruction of tissue by burning Chemabrasion Use of chemicals to remove outer layers of skin Cryosurgery Destruction or elimination of abnormal tissue cells (cry/o: cold; -surgery: operative procedure) Tissue Removal Curettage Removal of surface material by scraping Debridement Removal of dirt, foreign objects, damaged tissue, and cellular debris from a wound Prevention of infection and promotion of healing Irrigation and debridement Pressurized fluid to clean wound debris Tissue Removal Dermabrasion Involves use of revolving wire brush or sandpaper Electrodesiccation Destruction of tissue by the use of electric spark Incision Use of surgical instrument to cut open a lesion Tissue Removal Mohs' surgery Layers of cancerous tissue are removed and examined under the microscope Procedure is repeated until margin that is clear of all cancerous tissue is achieved Laser and Light Source Treatments of Skin Conditions Laser (Light Amplification by Stimulated Emission of Radiation) Laser tube filled with solid, liquid, or gas substance is stimulated to emit light at a specific wavelength Photosensitizing drug Administered topically or by injection After activation, drugs produce a form of oxygen that kills nearby cells Medications for Treatment of Skin Retinoids Derived from vitamin A and are used because of their effect on epithelial cell growth Topical steroids Derivatives of natural corticosteroid hormones Treatment of various skin disorders Cosmetic Procedures Blepharoplasty Surgical reduction of upper and lower eyelids by removing sagging skin (blephar/o: eyelid; -plasty: surgical repair) Botox Used to reduce moderate-to-severe frown lines, to treat migraines and muscle spasms Collagen replacement therapy Used for soft-tissue augmentation Cosmetic Procedures Dermatoplasty Replacement of damaged skin of a patient with the healthy tissue taken from a donor site Electrolysis Use of electric current to destroy hair follicles Lipectomy Surgical removal of fat from beneath the skin to improve physical appearance Cosmetic Procedures Liposuction Surgical removal of fat beneath the skin with the aid of suction Rhytidectomy Surgical removal of excess skin and fat from the face (rhytid: wrinkle; -ectomy: surgical removal) Cosmetic Procedures Sclerotherapy Injection of a saline sclerosing solution for treatment of spider veins (nonessential veins seen through the skin)