Integumentary System

Question 1

integumentary system (consists of)

Answer 1

• skin
• hair
• nails
• sweat glands
• sebaceous (oil) glands

Question 2

structure of skin

Answer 2

the skin consists of 2 distinct regions
- epidermis
- dermis
(hypodermis/superficial fascia)
(not considered part of the skin, but connects the skin to underlying structures like the muscles)

Question 3

epidermis

Answer 3

superficial region
consists of epithelial tissue
avascular(no blood vessels going through it)
contains sweat pores

Question 4

dermis

Answer 4

underlies epidermis
mostly strong, flexible, fibrous connective tissue
vascular(blood vessels, nerves, and lymphatic vessels)
provides cushion and protection
cell includes fibroblasts, macrophages, and occasionally mast cells(release histamines) and white blood cells

contains: sensory nerve fibers with free nerve endings, lamellar corpuscle, hair follicle receptor(root hair plexus), arrector pili muscle(raises the hair to cause goosebumps), sebaceous oil gland, epidermal hair follicles, hair root, and sweat glands

contains the papillary layer(closer to the surface) and then the reticular layer

dermal papillae are the curves that are right under the epidermis

Question 5

hypodermis (superficial fascia)

Answer 5

subcutaneous layer deep to skin
not part of skin but shares some functions
mostly adipose (fat) tissue that absorbs shock and insulates
anchors skin to underlying structures(mostly muscles)

Question 6

lamellar corpuscle

Answer 6

found in the deep layers of the skin - dermis and the hypodermis(not actually considered skin)

wrapped around to detect certain changes in frequencies

not a free nerve ending so it can pick up a specific change in a certain area within the dermis

Question 7

layers of the epidermis

Answer 7

• stratum corneum
• stratum granulosum
• stratum spinosum
• stratum basale

“come get sunburnt”

Question 8

stratum corneum

Answer 8

most superficial layer, thickest layer within the epidermis
dead, flat cells that are filled with keratin
glycolipids in the extracellular space that help with the thickness

help hold it together and prevent contaminants from coming in

Question 9

stratum granulosum

Answer 9

second layer of epidermis
flattened cells where organelles are going through deterioration
lamellar granules(release lipids) and keratohyalin granules in cytoplasm

Question 10

stratum spinosum

Answer 10

third layer of epidermis
cells begin to look spiny
keratinocytes that are held together by desmosomes
cells contain thick bundles of intermediate filaments make of pre-keratin

Question 11

stratum basale

Answer 11

deepest epidermal layer, thinnest layer of the epidermis
actively mitotic stem cells + some newly formed cells that become apart of the layers above

sometimes see melanocytes and tactile epithelial cells

Question 12

desmosomes

Answer 12

hold two sides of cells together
allows for movement(less constrictive than gap junctions)
holds together the keratinocytes in the stratum spinosum

Question 13

melanocyte

Answer 13

produces melanin(pigment)

more melanocytes produced with more exposure to the sun bc they shield from UV

Question 14

tactile epithelial cell

Answer 14

sensitive to touch/pressure
deep in the epidermis in the stratum basale that allows for us to tell how strong the force is/how strong the pressure is

Question 15

dendritic cell

Answer 15

macrophage/immune cell

Question 16

papillary dermis

Answer 16

top/superficial layer within the dermis, takes up much less of the dermal thickness compared to the reticular layer
areolar connective tissue - web-like fibrous tissue that is dense but allows for movement, consists of loose, interlacing collagen and elastic fibers and blood vessels

loose fibers allow phagocytes to patrol for microorganisms

on the top part of the papillary dermis - dermal papillae: superficial region of dermis that sends fingerlike projections up into epidermis(curvy thing)

Question 17

reticular dermis

Answer 17

bottom layer of the dermis, makes up about 80% of dermal thickness
dense, coarse, fibrous, irregular connective tissue
- many elastic fibers provide stretch-recoil properties
- collagen fibers provide strength and resiliency
- bind water, keeping skin hydrated

cleavage(tension) lines + flexure lines in reticular layer

cutaneous plexus: network of blood vessels between reticular layer and hypodermis(the superficial facia that is not considered part of the skin)
extracellular matrix contains pockets of adipose cells

Question 18

dermal papillae

Answer 18

the superficial region of the dermis that sends fingerlike projections up into the epidermis

curvy like thing right below epidermis

projections contain capillary loops, free nerve endings, and touch receptors ( tactile corpuscles = Meissner’s corpuscles)

in think skin, dermal papillae lie on top of dermal ridges which gives rise to epidermal redges

Question 19

friction ridges

Answer 19

what the ridges are collectively called - dermal ridges(where the dermal papillae sits) + epidermal ridges(dermal ridges gives rise to these)

these ridges:
enhance gripping ability
contribute to sense of touch
sweat pores in ridges leave unique fingerprint pattern

Question 20

cleavage (tension) lines

Answer 20

in reticular layer
caused by many collagen fibers running parallel to skin surface
externally invisible
very important to surgeons because incisions need to be parallel to the cleavage lines to heal more readily

Question 21

flexure lines

Answer 21

reticular layer of dermis
at or near joints
dermis is tightly secured to deeper structures
skin’s inability to slide easily for joint movement causes deep creases
visible on hands, wrists, fingers, soles, and toes

Question 22

simple squamous (epithelium cell)

Answer 22

simplest of the epithelial cells
single layer of flattened cells
disc-shaped central nuclei + sparse cytoplasm

function: allows materials to pass by diffusion and filtration in sites where protection is not important(very thin), secrete lubrication substances in serosae(linings of ventral body cavity)

location: kidney glomeruli(filtration), air sacs of lungs, lining of heart, blood vessels, and lymphatic vessels, serosae

Question 23

simple cuboidal (epithelium)

Answer 23

single layer of cubelike cells with large, spherical central nuclei

function: secretion and absorption, also provides cushion that simple squamous does not

location: kidney tubules, ducts and secretory portions of small glands, ovary surface

Question 24

simple columnar (epithelium)

Answer 24

single layer of tall cells with round-oval nuclei, many have microvilli, some have cilia, may contain mucus-secreting unicellular glands(goblet cells)

function: absorption, secretion of mucus, enzymes, and other substances., ciliated type propels mucus (or reproductive cells) by ciliary action

location: nonciliated type lines most of the digestive tract(stomach to rectum), gallbladder, and excretory ducts of some glands, ciliated variety lines small bronchi, uterine tubes, and some regions of the uterus

Question 25

pseudostratified columnar

Answer 25

single layer of cells of differing heights, some not reaching the free surface, nuclei seen at different levels, may contain mucus-secreting cells and bear cilia function: secrete substances, particularly mucus, propulsion of mucus by ciliary action location: ciliated variety lines the trachea and most of the upper respiratory tract, nociliated type in males' sperm-carrying ducts and ducts of large glands

Question 26

stratified squamous

Answer 26

thick epithelium composed of several cell layers basal cells are cuboidal or columnar and metabolically active/active in mitosis and produce the cells of the more superficial layers; surface cells are flattened(squamous); in the keratinized type, the surface cells are full of keratin and dead function: protects underlying tissues in areas subjected to abrasion location: nonkeratinized type forms in the moist linings of the esophagus, mouth, and vagina keratinized variety forms the epidermis of the skin, a dry epithelium

Question 27

transitional (epithelium)

Answer 27

resembles both stratified squamous and stratified cuboidal; basal cells cuboidal or columnar; surface cells dome-shaped or squamoslike, depending on the degree of organ stretch function: stretches readily, permits stored urine to distend urinary organ location: lines the ureters, bladder, and part of the urethra

Question 28

striae

Answer 28

extreme stretching of skin can cause dermal tears, leaving silvery white scars collagen and elastin being stretched "stretch marks"

Question 29

blisters

Answer 29

acutes, short-term traumas to skin can cause blisters, fluid-filled pockets that separate epidermal and dermal layers

Question 30

skin colors (what pigments)

Answer 30

made of 3 pigments: melanin, carotene, hemoglobin

Question 31

melanin

Answer 31

only pigment made in skin, made by melanocytes made from amino acid tyrosine by tyrosinase packaged into melanosomes that are sent to shield DNA of keratinocytes from damaging UV sunlight the more sun, the more need for protective shield, the more melanin will be produced 2 forms: reddish yellow to brownish black skin color differences are due to amount and form of melanin freckles and pigmented moles are local accumulations of melanin

Question 32

UV light exposure

Answer 32

excessive sun exposure damages skin elastic fibers clump, causing skin to become leathery can depress immune system and cause alterations in DNA that may lead to skin cancer UV light destroys folic acid(folic acid necessary for DNA synthesis, so insufficient folic acid is especially dangerous for developing embryos)

Question 33

photosensitivity

Answer 33

increased reaction to sun some drugs(antibiotics, antihistamines) and perfumes cause photosensitivity, leading to skin rashes

Question 34

carotene

Answer 34

yellow to orange pigment most obvious in palms and soles accumulates in stratum corneum and hypodermis can be converted to vitamin A for vision and epidermal health(structural support) * could be beneficial to store the carotene because the skin stretches across the whole body so it can be close to an organ that may need vitamin A quickly

Question 35

hemoglobin

Answer 35

pinkish hue of fair skin is due to lower levels of melanin skin of caucasians is more transparent, so color of hemoglobin shows through

Question 36

cyanosis

Answer 36

blue skin color(blood gets darker and reflects more blue light) low oxygenation of hemoglobin

Question 37

pallor

Answer 37

blanching/pale color anemia(low iron), low blood pressure, fear, anger

Question 38

erythema

Answer 38

redness fever, hypertension, inflammation, allergy

Question 39

jaundice

Answer 39

yellow cast liver disorders

Question 40

bruises

Answer 40

black-and-blue marks also referred to as ecchymoses or hematomas result of clotted blood beneath skin as clot is broken down, color of bruise changes

Question 41

brown/black "necklace"

Answer 41

hyperpigmented dark areas in axillae and around the neck may be a sign of insulin resistance and elevated blood glucose levels melanocytes produce melanin and then package them into melanosomes to go to the surface of the skin to protect the DNA from the UV light - the preferred way to get energy is glycolysis, so if there is a lot of glucose, there will be a lot of production from the melanocytes, so lots of melanin produced(why melanoma is so virulent - warburg theory, does glycolysis only even when oxygen is present)

Question 42

hair

Answer 42

consists of dead keratinized cells none located on palms, soles, lips, nipples, and portions of external genitalia functions: warn off insects on skin, hair on head guards against physical trauma, protect from heat loss, shield skin from sunlight nutrition and hormones affect hair growth follicles cycle between active and regressive phases(average 2.25 mm growth per week, lose 90 scalp hairs daily)

Question 43

vellus hair

Answer 43

pale, fine body hair of children and adult females

Question 44

terminal hair

Answer 44

coarse, long hair fond on scalp and eyebrows at puberty(appear in axillary(armpit) and pubic regions of both sexes, also on the face and necks of males)

Question 45

PCOS

Answer 45

polycystic ovary syndrome in women, ovaries and adrenal glands produce small amounts of androgens, but tumors/cysts on these organs can cause abnormally large amounts of androgens can result in excessive hairiness(hirsutism) and other signs of masculinization

Question 46

alopecia

Answer 46

hair thinning in both sexes after age 40

Question 47

true (frank) baldness

Answer 47

genetically determined and sex-influenced condition male pattern baldness - caused by a follicular response to DHT * dihydrotestosterone is really important for the release of sperm, increases as your age * male pattern baldness often causes the hair on top of your head to bald but the hair on your chest to increase

Question 48

telogen effluvium (TE)

Answer 48

abrupt hair thinning caused by an abundance of hair follicles entering resting phase at same time * can be due to stress-induced factors such as hormonal changes, surgery, severe emotional trauma, or crash dieting * other causes or thinking and/or texture change: drugs(antidepressants, chemo), hypothyroidism, and protein-deficient diets

Question 49

structure of a nail

Answer 49

phalanx - bone of fingertip nail bed nail matrix nail root eponychium(cuticle) proximal nail fold nail plate free edge of nail hyponychium(right under finger nail) * look at image of nail structure

Question 50

yellow-tinged nails

Answer 50

may indicated respiratory or thyroid gland disorder

Question 51

thickened yellow nails

Answer 51

can be due to fungal infection of nail

Question 52

koilonchya

Answer 52

"spoon nail" an outward concavity of nail may signal iron deficiency/protein deficiency middle section is curved inward

Question 53

beau's lines

Answer 53

horizontal lines across nails may indicated severe illnesses such as uncontrolled diabetes, heart attack, or chemo(strangeness in cell division)

Question 54

eccrine sweat glands

Answer 54

functions: temperature control, some antibacterial properties type of secretion: hypotonic filtrate of blood plasma method of secretion: merocrin(exocytosis) secretion exits ducts at: skin surface body location: everywhere, but especially palms, soles, forehead

Question 55

apocrine sweat glands

Answer 55

functions: may act as sexual scent glands type of secretion: filtrate of blood plasma with added proteins and fatty substances method of secretion: merocrin(exocytosis) secretion exits ducts at: usually upper part of hair follicle, rarely at skin surface body location: mostly axillary and anogenital regions

Question 56

sebaceous glands

Answer 56

functions: lubricate skin and hair, helps prevent water loss, antibacterial properties type of secretion: sebum (an oil secretion) method of secretion: holocrine (secretions released by the ruptures of the plasma membrane) secretion exits ducts at: skin surface body location: everywhere except palms and soles *jutting right into the hair follicle

Question 57

acne

Answer 57

usually, an infectious inflammation of the sebaceous glands, resulting in pimples (pustules or cysts) *associated with Propionibacterium acne infection

Question 58

whiteheads / blackheads

Answer 58

whiteheads are blocked sebaceous glands if secretion is oxidized, whitehead becomes a blackhead

Question 59

seborrhea

Answer 59

"cradle cap" overactive sebaceous glands in infants can lead to this begins as pink, raised lesions on scalp that turn yellow/brown and flake off

Question 60

functions of skin

Answer 60

- protection(barrier) - body temperature regulation - cutaneous sensations(Meissner's corpuscle, lamellar corpuscle, and free nerve endings) - metabolic functions - blood reservoir - excretions of wastes

Question 61

protection

Answer 61

skin is exposed to microorganisms, abrasions, temperature, extremes, and harmful chemicals three barriers: chemical barrier, physical barrier, biological barrier physical barrier: the main function of the skin is to form a barrier - the dead, flat, keratinized cells with the glycolipids surround them help keep water/polar molecules out some chemicals have limited penetrations of skin - lipid-soluble substances(can get past the glycolipids) - plant oleoresins (poison ivy) - organic solvents (acetone, paint thinner) - salts of heavy metals (lead, mercury) - some drugs (nitroglycerin - actives NO, activates CAMP, dilates coronary arteries) - drug agents (enhancers that help carry other drugs across skin)

Question 62

organic solvents / heavy metals passing through skin

Answer 62

if these molecules pass through the skin and enter blood, multiple organ systems can be devastated which can be lethal - kidneys can shut down - brain can be damaged - absorption of lead can result in anemia and neurological defects should never touch these compounds with bare hands

Question 63

body temperature regulation of the skin

Answer 63

insensible perspiration: under normal, resting body temperature, sweat glands produce about 500 ml/day of unnoticeable sweat sensible perspiration: designed to cool body, if body temperature rises, dilation of dermal vessels can increase sweat gland activity to produce 12 L(3 gallons) of noticeable sweat) cold external environment: dermal blood vessels constrict, skin temperature drops to slow passive heat loss

Question 64

metabolic functions of skin

Answer 64

- skin can synthesize vitamin D needed for calcium absorption in intestine - chemicals from keratinocytes can disarm some carcinogens(release TNF alpha that is an inflammatory cytokine) - keratinocytes can activate some hormones (convert cortisone into hydrocortisone) - skin makes collagenase, which aids in natural turnover of collage to prevent wrinkles

Question 65

blood reservoir of skin

Answer 65

skin can hold up to 5% of the body's total blood volume skin vessels can be constricted to shunt bloot to other organs, such as an exercising muscle

Question 66

excretion of skin

Answer 66

skin can secrete limited amounts of nitrogenous wastes, such as ammonia, urea, and uric acid sweating can cause salt and water loss

Question 67

skin cancer (types/risk factors)

Answer 67

most skin tumors are benign and do not metastasize risk factors: overexposure to UV radiation, frequent irritation of skin some skin lotions contain enzymes that can repair damaged DNA 3 major types of skin cancer: basal cell carcinoma, squamous cell carcinoma, melanoma *males have a much higher probability of melanoma than women

Question 68

basal cell carcinoma

Answer 68

least malignant and most common stratum basale cells(at the base of the epidermis) proliferate and slowly invade dermis and hypodermis cured by surgical excision in 99% of cases

Question 69

squamous cell carcinoma

Answer 69

second most common type, can metastasize involves keratinocytes of stratum spinosum usually is a scaly reddened papule on scalp, ears, lower lip, or hands good prognosis if treated by radiation therapy or removed surgically

Question 70

melanoma

Answer 70

cancer of melanocytes, most dangerous type because it is highly metastatic and resitant to chemotherapy treated by wide surgical excision accompanied by immunotherapy key to survival is early detection: ABCD rule A: asymmetry: the two sides the of the pigmented area do not match B: border irregularity, exhibits indentations C: color, contains several colors D: diameter, larger than 6 mm

Question 71

burns

Answer 71

tissue damage caused by heat, electricity, radiation, or certain chemicals - damage caused by denaturation of proteins, which destroys cells immediate threat is dehydration and electrolyte imbalance - leads to renal shutdown and circulatory shock to evaluate burns, the Rule of Nines is used - body is broken into 11 sections, with each section representing 9% of body surface(except the genitals, which account for 1%) - used to estimate volumes of fluid loss #1 cause of death from burns is from infections(no more barrier to stop pathogens from getting in) people with burns often lose a lot of weight because so much energy used to regenerate the cells that died

Question 72

first-degree burns

Answer 72

epidermal damage only localized redness, edema(swelling), and pain

Question 73

second-degree burn

Answer 73

epidermal and upper dermal damage(papillary layer) blisters appear first and second-degree burns are referred to as partial-thickness burns because only the epidermis and upper dermis are involved

Question 74

third-degree burn

Answer 74

entire thickness of skin involved, full-thickness burns(even down into the hypodermis) skin color turn gray-white, cherry red, or blackened no edema is seen and area is not painful because nerve ending are destroyed skin grafting usually necessary

Question 75

critical burns

Answer 75

>25% of body has second-degree burns >10% of body has third-degree burns face, hands, or feet bear third-degree burns

Question 76

treatment of burns

Answer 76

debridement(removal) of burned skin antibiotics temporary covering skin grafts

Question 77

developmental aspects of the integumentary system

Answer 77

fetal: by end of the 4th month, skin of fetus is developed infancy to adulthood: skin thickens and accumulates more subcutaneous fat; sweat and sebaceous gland activity increases leading to acne - optimal appearance during 20s and 30s - after age 30, affects of cumulative environmental assualts start to show - scaling and dermatitis become more common

Question 78

lanugo coat

Answer 78

delicate hairs in 5th and 6th month of a developing fetus

Question 79

vernix caseosa

Answer 79

sebaceous gland secretion that protects skin of fetus while in watery amniotic fluid

Question 80

aging skin

Answer 80

epidermal replacement slows - skin becomes thin, dry, and itchy(decreased sebaceous gland activity) subcutaneous fat and elasticity decrease, leading to cold intolerance and wrinkles increased risk of cancer due to decreased number of melanocytes and dendritic cells hair thinning ways to delay aging: UV protection, good nutrition, lots of fluids, good hygiene