Integumentary Sytem Flashcards
Master the skin.
What is the integumentary organ system?
A body system comprised of the cutaneous membrane (skin), hair, nails, associated glands, and the subcutaneous tissue. It functions include: protection against injury and infection, thermoregulation, sensory perception, regulation of water loss, and chemical synthesis.
What is a serous membrane?
A type of membrane that lines the body cavities that lack openings to the outside. They form the inner linings of the thorax and abdomen, and they cover organs within these cavities.
What is the definition of squamous?
Relating to, consisting of, or denoting a layer of epithelium that consists of very thin flattened cells.
What is a mucous membrane?
A type of membrane that lines the cavities and tubes that open to the outside of the body, including the oral and nasal cavities, and the tubes of the digestive, respiratory, urinary, and reproductive systems.
What is a synovial membrane?
A type of membrane that forms the inner linings of the joint cavities between the ends of bones at freely movable joints (synovial joints).
What is the cutaneous membrane?
An organ in the integumentary organ system more commonly known as the skin.
What is the epidermis?
The outer layer of skin that is composed of stratified squamous epithelium and lacks blood vessels.
What is the dermis?
The inner layer of skin that is thicker than the epidermis and contains fibrous connective tissue, epithelial tissue, smooth muscle tissue, nervous tissue, hair follicles, sebaceous glands, sweat glands, and blood vessels.
What is the subcutaneous layer?
Also called the hypodermis, this is a layer of tissues beneath the dermis that is comprised primarily of loose connective tissue and adipose tissue that bind the skin to underlying organs.
What is psoriasis?
A chronic, non-infectious skin disease in which cells in the epidermis divide 3 to 4 times more frequently than normal.
What are keratinocytes?
Older cells that produce keratin and make up 90% of epidermal cells.
What is the stratum corneum?
The outermost layer of the epidermis that is made up of 25 to 30 layers of tough, tightly packed, fully keratinized, and non-nucleated dead cells.
What is the stratum lucidum?
A layer between the stratum corneum and stratum granulosum that is found only on the soles and palms (thick skin).
What is the stratum granulosum?
A layer of the epidermis found beneath the stratum corneum, consisting of 3-5 layers of keratinocytes undergoing apoptosis.
What is the stratum spinosum?
A layer of the epidermis found under the stratum granulosum, consisting of 8 to 10 layers of cells with centrally located, large, oval nuclei.
What is the stratum basale?
The deepest layer of the epidermis, made up of a single layer of cuboidal or columnar keratinocytes that undergo mitosis and grow.
What are calluses?
Thickened areas of the skin that occur when the skin is rubbed or pressed regularly.
What are corns?
Horny, conical masses on the toes when poorly fitting shoes rub the skin.
What are melanocytes?
Cells of the stratum basale that synthesize the dark pigment melanin.
What are papillae?
Fingerlike oscillations in the basement membrane that pass into the spaces between cutaneous ridges.
What are Pacinian (Lamellar) corpuscles?
A type of dermal sensory receptor that is stimulated by heavy pressure and can sense vibration changes deep in the skin.
What are Meissner’s corpuscles?
Sensory receptors located in dermal papillae that are sensitive to light touch.
What are thermoreceptors?
Temperature receptors, including heat receptors and cold receptors.
What is sunburn?
An erythema resulting from excessive ultraviolet radiation, which denatures collagen and elastin while dilating blood vessels.
What are first-degree burns?
Burns that affect only the outer layer (epidermis) of the skin, causing pain, redness, and swelling.
What are second-degree burns?
Burns that affect both the outer (epidermis) and underlying layer (dermis) of skin, characterized by the presence of blisters.
What are third-degree burns?
Burns that affect all of the dermis and sometimes even the deep layers beyond the skin, resulting in black or white burned skin.
What are minor burns?
A category of burns that includes first-degree burns anywhere on the body and second-degree burns less than 2-3 inches wide.
What are major burns?
A category of burns that includes third-degree burns and second-degree burns more than 2-3 inches wide.
What is chicken pox (Varicella)?
A type of rash in which tiny pustules start on the back, chest, or scalp and spread for 3 or 4 days.
What is impetigo?
A bacterial rash characterized by thin-walled blisters and thick, crusted, yellow lesions.
What is Lyme disease?
A large rash resembling a bull’s-eye usually on the thighs or trunk.
What is scarlet fever?
A rash resembling sunburn with goose bumps that begins below the ears and spreads to the abdomen, limbs, and face.
What is shingles?
A rash characterized by small, clear blisters that appear on inflamed skin.
What is a hair follicle?
A tubelike depression that extends from the surface into the dermis in which a hair grows.
What is folliculitis?
An inflammation of the hair follicles in response to bacterial infection.
What is melanin?
A pigment that determines both skin and hair color and protects cells against ultraviolet damage.
What is albinism?
An inherited condition in which the skin and hair is nonpigmented due to a mutant melanin gene.
What is trichosiderin?
An iron pigment that renders hair red.
What is the arrector pili muscle?
A bundle of smooth muscle cells attached to each hair follicle that produces goose bumps.
What are nails?
Protective coverings on the ends of the fingers and toes made of packed, hard, keratinized cells.
What is the nail plate?
A covering produced by specialized epithelial cells that overlies the nail bed.
What is the nail bed?
The surface of the skin beneath the nail plate.
What is the lunula?
The whitish, thickened, half-moon-shaped region at the base of the nail that is the most actively growing region of the nail plate.
What are sebaceous glands?
Glands in the dermis that contain groups of specialized epithelial cells and are usually associated with hair follicles.
What is sebum?
A mixture of fats, cholesterol, proteins, inorganic salts, and pheromones that helps keep the hair and skin pliable.
What is acne?
A disorder of the sebaceous glands in which the glands are overactive or inflamed.
What are sweat glands (sudoriferous glands)?
Glands that secrete sweat and consist of a tiny tube that originates as a ball-shaped coil in the deeper dermis or superficial subcutaneous layer.
What are eccrine glands?
Also called merocrine sweat glands, these respond throughout life to body temperature elevated by environmental heat or physical exercise.
What is a pore?
The small tiny openings in the skin where sweat is secreted by a tube.
What are apocrine glands?
Certain sweat glands that produce scented fluid containing both lipids and proteins.
What is cyanosis?
The presence of a blue tint to skin, visible if a person stops breathing or has low blood oxygen concentration.
What is jaundice?
A condition in newborns characterized by slightly yellowish skin due to a buildup of bilirubin.
What is inflammation?
A normal response to injury or stress that results in swelling, redness, heat, and pain.
What is a birthmark?
A vascular or skin tumor of the skin and subcutaneous tissue, visible at birth or soon after.
What is a boil?
A bacterial infection of a hair follicle and/or sebaceous glands.
What is bilirubin?
A yellowish pigment that is normally processed by the liver and deposited into the small intestine for excretion.
What is inflammation?
A normal response to injury or stress that results in swelling, redness, heat, and pain due to vasodilation.
What is a carbuncle?
A bacterial infection, similar to a boil, that spreads into the subcutaneous tissues.
What is a cyst?
A liquid-filled sac or capsule.
What is eczema?
A noncontagious skin rash often accompanied by itching, blistering, and scaling.
What is erythema?
Reddening of the skin due to dilation of dermal blood vessels in response to various factors.
What is herpes?
An infectious disease of the skin usually caused by the herpes simplex virus, characterized by recurring formations of small clusters of vesicles.
What is a keloid?
An elevated, enlarging fibrous scar usually initiated by an injury.
What is a mole?
Also called a nevus, this is a fleshy skin tumor that is usually pigmented; colors range from brown to black.
What is pediculosis?
A disease produced by an infestation of lice.
What is pruritus?
Itching of the skin.
What is a pustule?
An elevated, pus-filled area.
What is scabies?
A disease resulting from an infestation of mites.
What is seborrhea?
Hyperactivity of the sebaceous glands, accompanied by greasy skin and dandruff.
What is an ulcer?
An open sore.
What is urticaria?
An allergic reaction of the skin that produces reddish, elevated patches (hives).
What is a wart?
Also called a veruca. A flesh-colored, raised area caused by a viral infection by HPV.
What is vitiligo?
An autoimmune condition in which the immune system mistakenly attacks melanocytes, causing the pigment to be lost from areas of the skin.
What are the ABCDE signs?
A method of assessing a skin lesion suspected of being a malignant melanoma: A-asymmetry, B-border, C-color, D-diameter, E-evolution.
What is tyrosinase?
An enzyme essential to the melanin synthesis pathway, catalyzing the conversion of tyrosine to dopa and dopa to dopaquinone.
What are melanosomes?
Organelles that are the cellular site of synthesis, storage, and transport of melanin.
What is eumelanin?
One of the two types of melanin, dark brown or black, providing protection against ultraviolet radiation.
What is pheomelanin?
One of the two types of melanin, light yellow or red, providing little protection against ultraviolet radiation.
What are striae?
Linear marks or grooves on the surface of the skin due to overstretching.
What is the cuticle?
The outermost layer of the hair, made of keratin, consisting of overlapping scales.
What is the cortex?
The intervening layer of the hair made of spindle-shaped cells with pigment granules in dark hair.
What is the medulla?
The innermost layer of the hair, made of cells that form a shaft through the middle of the hair.
What are ceruminous glands?
Modified apocrine sweat glands in the ear canal that produce earwax.
What are Langerhans cells?
Dendritic cells of the skin and mucosa that act as antigen-presenting immune cells.
What is vitamin D?
A fat-soluble vitamin that promotes calcium absorption and may be synthesized in response to sunlight.
What are Merkel cells?
Epidermal cells associated with the sense of light touch and discrimination of shapes and textures.
What is the hair root plexus?
A special group of nerve fiber endings that serves as a sensitive mechanoreceptor for touch sensation.
What is the anagen phase?
The growth phase of the hair cycle that lasts two to six years and determines hair length.
What is the catagen phase?
The transitional stage of the hair cycle that lasts about 1-2 weeks.
What is the telogen phase?
The resting phase of the hair cycle that lasts 5-6 weeks.
What are glycolipids?
Substances that help to waterproof the skin and prevent diffusion of water between cells.
What is keratin?
A protein that waterproofs the skin and protects from abrasions and bacteria.
What are lipid-soluble substances?
Substances that can penetrate the skin, including oxygen, carbon dioxide, and fat-soluble vitamins.
What are oleoresins?
Chemicals found in certain plants that can penetrate the skin.
What are organic solvents?
Substances that can penetrate the skin, including acetone and dry cleaning fluid.
What are salts of heavy metals?
Substances that can penetrate the skin, including lead and mercury.
What are topical medication patches?
Substances that can penetrate the skin, including nicotine and nitroglycerin.
What is the acid mantle?
A protective layer on the skin comprised of sweat and sebum, with a pH of 4 to 5.5.
What are human defensins?
Antimicrobial peptides that trigger an immune response or act on pathogens directly.
What are cathelicidins?
Proteins that prevent Strep A infection in wounded skin.
What are dermal macrophages?
Immune cells found in the dermis that attack bacteria and viruses via phagocytosis.
What is DNA structure’s role in UV radiation?
Electrons in DNA absorb ultraviolet radiation and convert it to heat.
What is vasodilation?
The increase in diameter of distal blood vessels to help dissipate heat from the body.
What is vasoconstriction?
The constriction of dermal blood vessels to keep blood close to the body’s core.
What are Ruffini’s corpuscles?
Sensory receptors located deep in the reticular layer that respond to distortion or stretching of the skin.
What is the nervous system’s role in the skin?
It innervates the skin and controls blood flow, glandular secretions, and sensory reception.
What are nociceptors?
Pain receptors that are especially abundant in the upper skin.
What are hair follicle receptors?
Sensory receptors that detect movement across the surface of the skin.
What is excretion in the skin?
The secretion of various waste products, including nitrogenous wastes and water.
What is the vitamin D pathway?
Vitamin D must be converted to its active form in two steps, first in the liver and then in the kidneys.
What is rickets?
A disease resulting from Vitamin D deficiency, causing an inability to properly regulate calcium and phosphate levels.
How many layers of skin are there?
2 layers.
How thick is the skin?
1.5 mm to 6.0 mm.
What is thin skin?
A type of skin that lacks stratum lucidum and has hair.
How thick is thin skin?
1 to 2 mm.
How thick is thin skin on the eyelids?
.5 mm.
What is thick skin?
A type of skin on the hands and soles of the feet that can be as thick as 6 mm.
What is Addison’s Disease?
An autoimmune disease where the adrenal glands stop producing enough cortisol, leading to hyperpigmentation.
What is lentigo?
A flat, brownish pigmented spot on the skin due to increased deposition of melanin.
What is intertrigo?
A superficial skin disorder characterized by skin reddening, maceration, burning, and itching.
What are the cardinal signs of inflammation?
Rubor (redness), calor (heat), dolor (pain), tumor (swelling), functio laesa (loss of function).
What is the papillary layer?
The layer of the dermis containing loose connective tissue with a rich supply of blood capillaries.
What is the reticular layer?
The major layer of the dermis containing dense irregular bundles of collagen and elastic fibers.
What are penetration enhancers?
Substances that decrease the barrier resistance of the stratum corneum to allow drug penetration.
What is collagen?
A structural protein that makes up about 70% of the dermis, providing strength and resilience.
What is elastin?
A protein fiber found in the dermis that gives elasticity to the skin.
What is hemoglobin?
The major molecule of erythrocytes that carries oxygen and gives blood its red coloration.
What is pallor?
A state in which the skin is very pale due to decreased blood flow to dermal blood vessels.
What is a hematoma?
A localized collection of blood outside the blood vessels that has clotted.
What is ecchymosis?
Commonly called a bruise, this is blood that has leaked out of a blood vessel under the skin.
What is leathery skin?
A change in skin appearance due to overexposure to UV radiation, leading to clumping of elastin fibers.
What is photosensitivity?
An abnormally high sensitivity to sunlight, increasing the risk of sunburn and skin damage.
What is actinic keratosis?
A rough, scaly, and precancerous patch of skin that results from solar exposure.
What is seborrhoeic keratosis?
Harmless skin lesions that appear during adult life, also known as basal cell papillomas.
What can develop during long exposure to sunlight?
Sunburn can develop during long exposure to sunlight.
What can ultraviolet rays from the sun lead to?
Ultraviolet rays from the sun can lead to skin damage and skin cancer.
What is melasma?
A chronic skin disorder resulting in symmetrical, blotchy, brownish facial pigmentation.
What is carotene?
A yellow-orange pigment that is a precursor for Vitamin A, found in the stratum corneum, fatty areas of the dermis, and hypodermis.
What are friction ridges?
Markings on fingertips that allow us to manipulate objects more easily.
What are flexion lines?
Lines that appear on flexor surfaces of digits, palms, wrists, and elbows.
What changes occur in the skin as we age?
The skin thins, repair becomes difficult, immune response reduces, and glandular activity decreases.
What is porrigo?
A condition more commonly known as dandruff.
What is prurigo?
Synonymous with pruritus, which is the itching of the skin.
What is serpigo?
A creeping or spreading skin disease, such as ringworm.
What are derivatives of skin?
Small groups of epidermal cells from the stratum basale that form hair follicles and glands during embryonic development.
What are end bulbs of Krause?
Sensory receptors that detect cold, occurring most numerously in the conjunctiva of the eye and genitals.
What are free nerve endings?
Sensory receptors that can detect cold, hot, and pain.
What is the hair shaft?
The portion of the hair that projects from the skin surface.
What shape does curly hair have?
Curly hair has a flattened oval (ribbon-like) shaped shaft.
What shape does straight hair have?
Straight hair has a round shaft.
What is the hair bulb?
The part of the base of the hair follicle that houses papilla containing blood vessels.
What is the hair matrix?
The part of the base of the hair follicle responsible for hair growth.
How many hairs are on the body of an average individual?
5 million
How many hairs are on the scalp on average?
100,000
What percent of hairs are in the growth phase (anagen) at any given time?
85%
How fast does hair grow?
10 cm per year
What is club hair?
A hair in its resting period, fully grown but not shed yet.
What are the functions of hair?
Protection from injury and sunlight, foreign particles, and aid in sensory reception.
What is the stratum germinativum?
A layer of the skin made up of both the stratum basale and stratum spinosum.
What is sweat composition?
98% water, 2% dissolved salts and nitrogenous wastes.
What is the free edge of the nail?
The part of the nail plate that extends past the distal end of the digit.
What is the eponychium?
A narrow band of epidermis on top of the lunula, also called the cuticle.
What is the hyponychium?
The thickened stratum corneum under the distal edge of the nail plate.
What is the perionychium?
The pieces of skin directly surrounding the sides of a nail.
What is the nail matrix?
The part of the nail where growth occurs.
What are the functions of the nail?
Grasping/manipulating objects, protection of ends of digits, scratching.
What is a lesion?
A variation from the normal structure of the skin.
What are elevated lesions?
Skin variations that cast a shadow outside the edges, such as warts and plaques.
What is a plaque?
A solid, raised, flat-topped lesion greater than 1 cm in diameter.
What is a blister?
A local swelling of the skin filled with clear fluid that results from burning or irritation.
What are flat lesions?
Skin variations that do not cast a shadow, such as scabs and hives.
What are depressed lesions?
Skin variations that cast a shadow within their edges, such as lacerations and ulcers.
What is a fissure?
A linear-like cleavage of skin, smaller than a skin laceration.
What is Tinea Pedis?
Athlete’s foot; a dermatophytosis of the feet caused by dermatophytes.
What is Tinea?
Any of numerous different fungal infections of the skin by ringworm.
What is contact dermatitis?
A condition where the skin becomes red, sore, or inflamed after contact with a substance.
What is irritant dermatitis?
The more common type of contact dermatitis caused by contact with irritants.
What is allergic dermatitis?
A type of dermatitis caused by exposure to an allergen.
What is dermatitis treatment?
Washing with water, avoiding irritants, and using corticosteroid creams.
What is a fourth-degree burn?
A burn that involves injury to deeper tissues, such as muscle or bone.
What is the rule of nines?
A system to estimate burn damage with multiples of nines.
What is basal cell carcinoma?
The least malignant but most common form of skin cancer.
What is squamous cell carcinoma?
The second most common form of skin cancer, usually induced by the sun.
What is malignant melanoma?
The least common but most deadly form of skin cancer.
How long does it take for a cell produced by the stratum basale to rise to the surface?
One month
What is a desmosome?
Protein junctions that hold epithelial cells tightly together.
What is the surface area of the skin?
1-2 meters
What percent of one’s body weight is the skin?
12-15%
What is vellus hair?
Short, fine, colorless hair found all over the body.
What is lanugo hair?
Special downy hair that covers the fetus inside the womb by the end of the 5th month.
What is terminal hair?
What the average person thinks of when thinking of hair.
What are mammary glands?
Modified apocrine sweat glands that secrete milk instead of sweat.
What are lamellar bodies?
Granule-producing cells found in the stratum granulosum that waterproof the skin.
What is keratohyalin?
A protein structure involved in keratinization found in the stratum granulosum.
What are fibroblasts?
The main type of cell in the dermis that synthesizes the extracellular matrix and collagen.
What is a hemidesmosome?
Structures that attach one cell to the extracellular matrix in the epidermis.
