Ch. 4 Integumentary System PDF

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Medical Terminology for Health Care Professionals, 9th ed....

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Ch. 4 Integumentary System Anatomy and physiology    

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Integumentary system- is composed of the skin (the largest organ of the body) and its accessory structures, the hair, nails, sebaceous glands, and sweat glands. Skin- protection, regulation, sensation, and secretion. Epidermis- outer protective covering of the body that can be divided into 5 striata (in order as the layers evolve and mature) stratum basale (basal layer)- innermost epidermal layer responsible for regeneration of the epidermis. Damage to this layer, as in severe burns, necessitates the use of the skin grafts (SG). Melanin is formed in this layer. Melanin- the pigment that gives color to the skin. It is formed in the basal layer. The more abundant the melanin, the darker the color of the skin. stratum spinosum- means "spiny layer." Each time a stem cell divides, one of the daughter cells is pushed into this layer. Contains Langerhans cells, which are responsible for stimulating a defence against invading microorganisms and superficial skin cancers. stratum granulosum- large amounts of keratin, a protein substance, are made here. In humans, keratin is the basic structural component of hair and nails. stratum lucidum- present in thick skin of the palms and soles. Cells are flattened, densely packed, and filled with keratin. stratum corneum- outermost, horny layer, consisting of dead cells. Forms protective covering for the body. Keratinization- process during which the cells lose their nuclei and become hard or horny. Forms protective covering for the body. Dermis- nourishes the epidermis, provides strength, and supports blood vessels. Papillae- produce ridges that are one's fingerprints Subcutaneous tissue- supports, nourishes, insulates, and cushions the skin. Hair- provide sensation and some protection for the head. Hair around the eyes, in the nose, and in the ears filters out foreign particles. Nails- protect ends of fingers Sebaceous (oil) glands- lubricate the hair and skin Sweat glands- secrete sweat of perspiration, which helps to cool the body by evaporation. Sweat also rids the body of waste. Also referred to as sudoriferous glands.

Functions of the Skin Skin- the external covering of the body. In an average adult it covers more than 3,000 square inches of surface area, weighs more than 6 pounds, and is the largest organ of the body. Protection  Functions o Protective membrane against invasion by bacteria o Protects against mechanical injury o Serves to inhibit excessive loss of water and electrolytes o Provides a reservoir for storing food and water o Guards against excessive exposure to the sun's ultraviolet rays and it helps to produce the body's supply of vitamin D. Regulation  Functions o Serves to raise or lower body temperature as necessary. o When the body needs to lose heat, the blood vessels in the skin dilate, bringing more blood to the surface for cooling by radiation. o At the same time, the sweat glands are secreting more sweat for cooling by means of evaporation. o When the body needs to conserve heat, the reflex actions of the nervous system cause the skin's blood vessels to constrict, thereby allowing more heat-carrying blood to circulate to the muscle and vital organs. Sensation 

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Functions o The skin contains millions of microscopic nerve endings that act as sensory receptors for pain, touch, heat, cold, and pressure. Secretion  Functions o The skin contains millions of sweat glands, which secrete perspiration or sweat, and sebaceous glands, which secrete oil (sebum) for lubrication. o Sebum is an oily secretion that acts to protect the body from dehydration and possible absorption of harmful substances.

Layers of the skin

Epidermis 

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Epidermis- the outer layer of the skin. o It is the thinnest on the eyelids at 0.05 mm o It is the thickest on the palms and soles at 1.5 mm Can be divided into five striata o Stratum basale o Stratum spinosum o Stratum granulosum o Stratum lucidum o Stratum corneum

Dermis 

Sometimes called the corium or true skin

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Divided into 2 layers o Upper layer or papillary layer  Arranged into parallel rows of microscopic structured called papillae, which produce the ridges of the skin that are one's fingerprints or footprints. o Lower layer or reticular layer  Composed of white fibrous tissue that supports the blood vessels The dermis is attached to underlying structures by the subcutaneous tissue. o This tissue supports, nourishes, insulates, and cushions the skin.

Accessory Structure of the Skin

Hair       

Hair- a thin, threadlike structure formed by a group of cells that develop within a hair follicle or socket. Each hair is composes of a shaf, which is the visible portion, and a root, which is embedded within the follicle. At the base of each follicle is a loop of capillaries enclosed within connective tissue called the hair papilla. The arrector pili muscle attaches to the side of each follicle. o Goosebumps are formed by the contraction of these muscles. Hair grows at approximately 0.5 inch a month. Hair color is determined by the differences in the type and amount of melanin (pigment) produced by melanocytes at the hair papilla. The color of hair is genetically determined.

Nails          

Fingernails and toenails are horny cell structures of the epidermis and are composed of hard keratin. A nail consists of a nail body that covers the ends of fingers and toes. o Nail body- the visible dense mass of dead keratinized cells The body of the nail covers an area of epidermis known as the nail bed. The nail root is an epithelial fold not visible from the surface. The eponychium or cuticle is a portion of the epithelial fold that extends over the exposed nail adjacent to the root. Lunula- blood vessels near the nail root that are obscured, leaving a pale crescentshaped area. The free edge of the nail is the extension of the nail plate that protects the tip of the finger or toe. Average growth is 1 mm per week A lost fingernail regenerates in 3 1.2 to 5 1/2 months A lost toenail may require 6-8 months for regeneration.

Sebaceous (Oil) Glands 

Sebaceous glands- the oil-secreting glands of the skin. o They have tiny ducts that open into the hair follicles, and their secretion, sebum, lubricates the hair as well as the skin. o The amount of secretion is controlled by the endocrine system and varies with age, puberty, and pregnancy.

Sweat Glands   

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The skin has 2 major types of sweat glands: eccrine and apocrine. Eccrine sweat glands- opens directly onto the surface of the skin. They help to maintain homeostasis, primarily by stabilizing body temperature. Apocrine sweat glands- opens into the hair follicle, leading to the surface of the skin. They are found in the skin of the areola (pigmented area) of the breast, armpit, groin, eyelid, and ear. Hypohydrosis- the inability to sweat Hyperhidrosis- overactive sweat glands that cause a chronic condition of excessive sweating

Building Your Medical Library Combining Forms  Acr/o - extremity  Aden/o - gland  albin/o - white  ang/i - vessel  carnin/o - cancer  caus/o - burn, burning  cellul/o - little cell  cutane/o - skin  derm/a - skin

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derm/o - skin dermat/o - skin erythr/o - red follicul/o - little bag hidr/o - sweat icter/o -jaundice integument/o - a covering jaund/o - yellow kel/o - tumor kerat/o - horn leuk/o - white melan/o - black myc/o - fungus onych/o - nail pachy/o - thick pedicul/o - a louse plak/o - plate prurit/o - itching rhytid/o - wrinkle scler/o- hard, hardening seb/o - oil therm/o - hot, heat trich/o - hair ungun/o - nail vuls/o - to pull xanth/o - yellow xer/o - dry

Word Roots  actin (R )- ray, light  chym (R )- juice  chord (R )- cord  coriat (R )- corium  cubit (R )- to lie  log (R )- study  lopec (R )- fox mange  miliar (R )- millet (tiny)  pannicul (R )- fat cells  tel (R )- end, distance

Word Parts of Terms  

Acne- inflammatory condition of the sebaceous glands and the hair follicles. Acrochordon- small outgrowth of epidermal and dermal tissue; skin tags

acr/o (CF)- extremity chord- cord -on- pertaining to Actinic dermatitis- inflammation of the skin caused by exposure to radiant energy, such as x-rays, ultraviolet light and sunlight.  actin- ray  -ic- pertaining to  dermat- skin  -itis- inflammation Albinism- genetic condition in which there is partial or total absence of pigment in skin, hair, and eyes.  albin- white  -ism- condition Alopecia- absence or loss of hair, especially of the head; baldness; alopecia areata is loss of hair in defined patches usually involving the scalp.  a- without, lack of  lopec- fox mange  -ia- condition Androgenetic alopecia- a common form of hair loss in both men and women. In men, hair is lost in a well-defined pattern, beginning above both temples and receding to form a characteristic "M" shape. In women, the hair becomes thinner all over the head and the hairline does not recede. Anhidrosis- abnormal condition in which there is a lack of or complete absence of sweating. May be congenital or disease related, generalized or localized, temporary or permanent.  an- without, lack of  hidr- sweat  -osis- condition Autograf-graft taken from one part of the patient's body and transferred to another part of the same patient.  auto- self  -graf- grafting knife Avulsion- process of forcibly tearing off a part or structure of the body, such as a finger or toe.  a- apart  vuls- to pull  -ion- process Basal cell carcinoma (BCC)- epithelial malignant tumor of the skin that rarely metastasizes. It usually begins as a small, shiny papule and enlarges to form a whitish border around a central depression.  carcin- cancer  -oma- tumor Bite- injury in which a part of the skin is torn by an insect, animal, or human, resulting in a combination of an abrasion, puncture, or laceration.   

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Boil- acute, infected, painful nodule formed in the subcutaneous layers of the skin, gland, or hair follicle; most often caused by the invasion of staphylococci; furuncle. Bulla- larger blister; bleb. Burn- injury to tissue caused by heat, fire, chemical agents, electricity, lightning, or radiation; classified according to degree or depth of skin damage. The three classifications are first degree, second degree, and third degree. Candidiasis- infection of the skin or mucous membranes with any species of Candida but chiefly Candida albicans. Candida is a genus of yeasts. Carbuncle- infection of the subcutaneous tissue, usually composed of a cluster of boils. Causalgia- intense burning pain associated with trophic skin changes such as thinning of hair and loss of sweat glands due to peripheral nerve damage.  caus- buring  -algia- pain Cellulitis- an acute, diffuse inflammation of the skin and subcutaneous tissue characterized by local heat, redness, pain, and swelling.  cellul- little cell  -itis- inflammation Cicatrix- scar left after the healing of a wound. Comedo- blackhead Corn- thickening of the skin that may be soft or hard depending on location; caused by local pressure, friction, or both that irritates tissue over a bony prominence, such as from ill-fitting shoes. Cryosurgery- technique of using subfreezing temperature (usually with liquid nitrogen) to produce well-demarcated areas of cell injury and destruction. Cutaneous- pertaining to the skin  cutane- skin  -ous- pertaining to Cyst- closed sac that contains fluid, semifluid, or solid material. Debridement- removal of foreign material or damaged or dead tissue, especially in a wound. It is used to promote healing and to prevent infection. Decubitus (decub) ulcer- an area of skin and tissue that becomes injured or broken down. Also known as a bedsore or pressure ulcer. The literal meaning of the word is decubitus is a "lying down".  de- down  cubit- to lie  -us- pertaining to Dehiscence- surgical complication where there is separation or bursting open of a surgical wound. Dermabrasion- skin resurfacing procedure to remove acne scars, nevi, tattoos, or fine wrinkles by using a rapidly rotating device to sand the outer layers of the skin. Dermatitis- inflammation of the skin.  dermat- skin  -itis- inflammation Dermatologist- physician who specializes in the study of the skin.

dermat/o- skin log- study -ist- one who specializes Dermatology- study of the skin  dermat/o- skin  -logy- study of Dermatome- surgical instrument used to produce thin slices of skin.  derm/a- skin  -tome- instrument to cut Dermomycosis- skin condition caused by a fungus; also called dermatomycosis or tinea.  derm/o- skin  myc- fungus  -osis- condition Ecchymosis- abnormal condition in which the blood seeps into the skin causing discolorations ranging from blue-black to greenish yellow.  ec- out  chym- juice  -osis- condition Eczema- an acute or chronic inflammatory skin disorder characterized by erythema, papules, vesicles, pustules, scales, crusts, or scabs alone or in combination. The most promising treatment involves nonsteroidal skin medications classified as topical immunomodulators (TIMs) or topical calcineurin (a protein phosphatase inhibitor). Erythema- redness of the skin; may be caused by capillary congestion, inflammation, heat, sunlight or cold temperature. Erythema infectiosum- known as fifth disease, a mild, moderately contagious disease caused by the human parvovirus B-19. It is most commonly seen in school-age children and is thought to be spread via respiratory secretions from infected persons. Erythroderma- abnormal redness of the skin occurring over widespread areas of the body.  erythr/o- red  -derma- skin Eschar- slough, scab Excoriation- abrasion of the epidermis by scratching, trauma, chemicals, or burns.  ex- out  coriat- corium  -ion- process Exudate- an oozing of pus or serum Folliculitis- inflammation of a follicle or follicles.  follicul- little bag  -itis- inflammation Gangrene- literally means an eating sore. It is a necrosis, or death, of tissue or bone that usually results from a deficient or absent blood supply to the area. Herpes simplex- an inflammatory skin disease caused by a herpes virus (type 1); cold sore or fever blister.   

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Hidradenitis- inflammation of the sweat glands.  hidr- sweat  aden- gland  -itis- inflammation Hives- eruption of itching and burning swellings on the skin; urticaria. Hyperhidrosis- abnormal condition of excessive sweating  hyper-excessive  hidr- sweat  -osis- condition Hypodermic- pertaining to under the skin or inserted under the skin, as a hypodermic injection. Hypohydrosis- abnormal condition of the inability to sweat; also called anhidrosis.  hypo- under  hidr- sweat  -osis- condition Icteric- pertaining to jaundice  icter- jaundice  -ic- pertaining to Impetigo- skin infection marked by vesicles or bullae; usually caused by streptococcus (strep) or staphylococcus (staph). Integumentary- covering; the skin, consisting of the dermis and the epidermis.  integument- a covering  -ary- pertaining to Intradermal- pertaining to within the skin, as an intradermal injection.  intra- within  derm- skin  -al- pertaining to Jaundice- yellow, a symptom of a disease in which there is excessive bile in the blood; the skin, whites of the eyes, and mucous membranes are yellow; icterus.  jaund- yellow  -ic(e )- pertaining to Keloid- overgrowth of scar tissue caused by excessive collagen formation.  kel- tumor  -oid- resemble Lentigo- a flat, brownish spot on the skin sometimes caused by exposure to the sun and weather. Leukoderma- localized loss of pigmentation of the skin.  leuk/o- white  -derma- skin Leukoplakia- white spots or patches formed on the mucous membrane or the tongue or cheek; the spots are smooth, hard, and irregular in shape and can become malignant.  leuk/o- white  plak- plate  -ia- condition

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Lupus- originally used to describe a destructive type of skin lesion; current usage of the word is usually in combination with the words vulgaris or erythematosus. Measles- highly contagious illness caused by the rubeola virus, which replicates in the nose and throat of an infected child or adult. Melanoma- cancer that develops in the pigment cells of the skin; malignant black mole or tumor. Often the first sign of melanoma is change in the size, shape, or color of a mole. (Asymmetry, Border, Color, Diameter, Evolving).  melan- black  -oma- tumor Miliaria- rash with tiny pinhead-sized papules, vesicles, and/or pustules commonly seen in newborn and infants; prickly heat. It is caused by excessive body warmth. There is retention of sweat in the sweat glands, which have become blocked or inflamed, and then rupture or leak into the skin.  miliar- millet  -ia- (tiny) condition Mole- pigmented, elevated spot above the surface of the skin; nevus. Onychia- inflammation of the nail bed, resulting in loss of a nail.  onych- nail  -ia- condition Onychomycosis- a fungal infection of the nails.  onych/o- nail  myc- fungus  -osis- condition Pachyderma- thick skin; also called pachydermia.  pachy- thick  -derma- skin Panniculectomy- surgical excision of fat cells in the superficial fascia; a body-contouring surgical procedure that removes hanging fat and skin, typically after massive weight loss; may be performed as a standalone procedure or combined with a tummy tuck (abdominoplasty).  pannicul- fat cells  -ectomy- surgical excision Paronychia- infectious condition of the marginal structures surrounding the nail.  para- next to  onych- nail  -ia- condition Pediculosis- condition of infestation with lice.  pedicul- a louse  -osis- condition Petechiae- small, pinpoint, purplish hemorrhagic sports on the skin. Pruritus- severe itching  prurit- itching  -us- pertaining to

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Psoriasis- chronic skin condition characterized by frequent episodes of redness, itching, and thick, dry scales on the skin. Purpura- purplish discoloration of the skin caused by extravasation of blood into tissues. Rhytidoplasty- plastic surgery for the removal of wrinkles.  rhytid/o- wrinkle  -plasty- surgical repair Rosacea- a chronic disease of the face marked by varying degrees of papules, pustules, erythema, telangiectasia, and hyperplasia of the soft tissues of the nose; usually occurs in middle-aged and older people. Roseola- any rose-colored rash marked by maculae or red spots on the skin. Rubella- contagious viral infection best known by its distinctive red rash; also called German measles and three-day measles. Scabies- contagious skin disease characterized by papules, vesicles, pustules, burrows, and intense itching; it is caused by an arachnid, Sarcoptes scabiei, variety hominis, the itch mite; also called the itch. Scar- mark left by the healing process of a wound, sore, or injury. Scleroderma- chronic condition with hardening of the skin and other connective tissues of the body.  scler/o- hard, hardening  -derma- skin Seborrhea- excessive flow (secretion) of oil from the sebaceous glands.  seb/o- oil  -rrhea- flow Seborrheic keratosis- condition occurring in older people wherein th...