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56 Cards in this Set
- Front
- Back
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Integumentary System
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The skin, the largest organ in the body by weight, and its various accessory structures.
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Functions of the Skin
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Protective covering
Retards water loss Helps regular body temperature Houses sensory receptors Synthesizes various chemicals Excrete small quantities of waste. |
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Skin (cutaneous membrane) has two layers
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1. epithelial tissue
2. connective tissue |
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Epidermis
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Outer layer of the skin composed of stratified squamous epithelium.
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Dermis
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Inner layer of the skin, thicker than the epidermis, made up of connective tissue containing collagen and elastic fibers, smooth muscle tissue, nervous tissue, and blood.
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Subcutaneous Layer
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Masses of areolar and adipose tissue bind the skin to underlying organs. It consists of collagenous and elastic fibers.
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What are the functions of the subcutaneous layer?
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Insulation
Helps to conserve body heat Impeding the entrance of heat from the outside. Contains major blood vessels that supply the skin. |
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Stratum basale
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Deepest layer of epidermal cells.
Close to the dermis Nourished by dermal blood vessels |
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Keratinization
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Strands of tough, fibrous, waterproof keratin proteins are synthesized and stored in a cell.
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Stratum corneum
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Outermost layer of the epidermis
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Decubitis ulcer
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Bedsores developed by blood vessels not receiving blood flow due to pressure for a prolonged period.
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Four layers of the epidermis
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1. stratum basale
2. stratum spinosum 3. stratum granulosum 4. stratem corneum |
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Stratum lucidum
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Thickened skin of the palms and soles.
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Calluses
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1. Growth of thickened areas on the palms and soles.
2. Keratinized conical masses on the toes called corns. |
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Psoriasis
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Chronic skin disease where cells in the epidermis divide seven times more frequently than normal.
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Functions of the epidermis
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Protection
Shields tissue against water loss Protect against mechanical injury Keeps out disease causing micro-organisms. |
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Melanocytes
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Specialized cells in the epidermis produce the dark pigment melanin from the amino acid tyrosine. They live in the stratum basale layer of the epidermis.
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Hemoglobin
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Blood in the dermal vessels add color to the skin. When high levels of hemoglobin, skin looks pink. With low levels, skin appears bluish. (cyanosis).
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Carotene
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Yellow-orange plant pigment found in yellow vegetables. Skin pigment can show the effects of eating a lot of these vegetables.
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What is the function of melanin?
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Absorbs ultraviolet radiation
Provides skin color Protects against skin mutations |
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Dermal papillae
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Increases the surface area where epidermal cells receive oxygen and nutrients from dermal capillaries.
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Fingerprints
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Undulations of the skin at the distal end of the palmar surface of a finger. They are individually unique.
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Dermis
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Inner skin layer, approx. 1.0 - 2.0 mm thick. Contains dense irregular connective tissue, elastic fibers, some muscle fibers, skeletal fibers, nerve cell processes. Does not shed.
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Nails
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Nails are the protective coverings on the ends of the fingers and toes, made of epithelial cells and keratinized scales.
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Parts of the nail
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Nail plate
Nail bed Lunula |
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Hair Follicles
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Hair develops from a group of epidermal cells at the base of a tubelike depression called a hair follicle, which contains the hair root.
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Eumelanin
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Hair pigment that epidermal melanocytes produce. Dark hair has more of the brownish-black eumelanin.
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Pheomelanin
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Hair pigment that epidermal melanocytpes produce. Blonde and red hair have more of the reddish-yellow pheomelanin.
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Baldness / Hair Loss
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Alopecia
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Hair standing on end
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A bundle of smooth muscle cells, forming the arrector pili muscle attaches to each hair folicle. Functions with nerve impulses.
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Sebaceous glands
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Sebaceous glands contain groups of specialized epithelial cells and are usually associated with hair follicles.
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Sebum
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Cells produce globules of fatty material which combines with cellular debris. This is called sebum.
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Sudoriferous glands
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Sweat glands consisting of a tiny tube located in the deeper dermis. It is lined with sweat-secreting epithelial cells.
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Eccrine glands
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Eccrine glands are the most numerous sweat glands in the body, responding to heat or physical exercise of the body.
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What does sweat contain?
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Sweat is mostly water, but also contains salts, and wastes such as urea and uric acid.
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Apocrine glands
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Sweat glands that develop a scent as skin bacteria metabolize them. Noticeable during puberty, sexual arousal, emotional incidents, etc.
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Acne vulgaris
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Disorder of the sebaceous glands. Excess sebum and squamous epithelial cells clog the glands producing blackheads and whiteheads. Hormone induced.
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Ceruminous glands
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Glands located in the external ear canal that produce ear wax.
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Mammary glands
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Located in the breasts and their sole function is to secrete milk.
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Body heat loss
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Radiation is the primary means of body heat loss. Infrared heat rays escape from warmer surfaces to cooler surroundings.
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Conduction
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Heat moves from the body directly into the molecules of cooler objects in contact with its surface. Like sitting in a cold chair.
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Convection
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As air becomes heated, it moves away from the body carrying the heat with it, which is replaced by cooler air moved towards the body.
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Evaporation
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When body temperature rises above normal the eccrine sweat glands release sweat carrying heat away from the surface, cooling the skin.
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Hyperthermia
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Hot, humid conditions when sweat cannot evaporate from the skins surface causing body temperature to rise.
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Hypothermia
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Prolonged exposure to cold or as part of an illness causes lowered body temperature.
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Inflammation
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Normal response to injury or stress. Blood vessels dilate and become more permeable, allowing fluids to leak into the damaged tissues.
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Clot due to injury
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A clot consists mainly of fibrous protein (fibrin) that forms from another protein in the plasma, blood cells, and platelets.
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Scar
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Extensive production of collagenous fibers may form an elevation above the normal epidermal surface.
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Granulation
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A granulation consists of a new branch of blood vessel and a cluster of collagen secreting fibroblasts that the vessel nourishes.
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Solar erythema
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Sunburn due to an inflammatory reaction of the skin to excessive exposure to ultraviolet radiation in sunlight.
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First Degree Burn
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Superficial, partial-thickness burn affecting only the epidermis.
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Second Degree Burn
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Deep, partial-thickness burn affecting the epidermis and part of the dermis.
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Third Degree Burn
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A burn that destroys the epidermis, dermis and the accessory structures of the skin.
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Skin Grafting
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1. autograft - from same person
2. allograft - from another person 3. skin substitutes |
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Rule of Nines
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System used to determine percentage of burns on the body by subdividing the body's skin surface into regions. (9% each or multiples of 9%)
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Life Span Changes
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Wrinkling, sagging, age spots, reduced number of sweat glands, shrinking capillary beds in the skin, diminished ability to activate vitamin D.
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