Anatomy Test 3: Chapter 6

Front 1

What does the integumentary system consist of?

Back 1

skin and its accessory organs; hair, nails, and cutaneous glands

Front 2

What is the most vulnerable organ?

Back 2

skin

Front 3

This skin makes up ____% of body weight.

Back 3

15%

Front 4

Where is thick skin found?

Back 4

on the palms and soles and corresponding surfaces on fingers and toes

has sweat glands but no hair follicles or sebaceous (oil) glands

Front 5

The epidermis is avascular. What does this mean?

Back 5

gains nutrients and gets rid of wastes through diffusion (because it contains no blood vessels)

Front 6

List the functions of the skin.

Back 6

resistance to trauma and infection --> keratin, acid mantle

other barrier functions --> waterproofing, UV radiation, harmful chemicals

Vitamin D synthesis --> skin is the first step of vitamin D synthesis, liver and kidneys complete process

sensation --> skin is our most sensitive organ

thermoregulation --> thermoreceptors, vasoconstriction/vasodilatation

nonverbal communication --> acne, birthmark, or scar

transdermal absorption --> administration of certain drugs steadily through the skin via adhesive patches

Front 7

True or false: The skin carries out the first step in the synthesis of vitamin D.

Back 7

true

Front 8

True or false: Living keratinocytes exfoliate from the epidermis as tiny specks called dander.

Back 8

false

Front 9

True or false: The deeper of the two layers of the skin is the hypodermis.

Back 9

false

Front 10

True or false: The youngest keratinocytes are found in the stratum basale.

Back 10

true

Front 11

True or false: Melanin, hemoglobin, and carotene give color to the skin.

Back 11

true

Front 12

True or false: Albinism is the genetic lack of melanin that results in a milky white coloration of the skin.

Back 12

true

Front 13

True or false: Embarrassment can be perceived by an abnormal coloration of the skin called cyanosis.

Back 13

false

Front 14

True or false: Freckles are elevated patches with an abnormal coloration of the skin.

Back 14

false

Front 15

True or false: Straight hair is round, wavy hair is oval, and curly hair is relatively flat.

Back 15

true

Front 16

True or false: Hair and nails are composed of collagen.

Back 16

false

Front 17

True or false: Merocrine sweat glands are associated with hair follicles in the pubic and anal regions, axilla, areola, and beard.

Back 17

false

Front 18

True or false: Pattern baldness is relatively rare in women because women have lower testosterone levels than men.

Back 18

true

Front 19

True or false: The acidity of sweat contributes to the acid mantle that inhibits bacterial growth in the skin.

Back 19

true

Front 20

True or false: Debridement is not necessary to infection control.

Back 20

false

Front 21

True or false: The three forms of skin cancer are defined by the types of cells from which they originate.

Back 21

true

Front 22

Which epithelium is composed of dead keratinized stratified squamous cells, lacks blood vessels, and depends on diffusion of nutrients from underlying connective tissue?

Back 22

epidermis

sparse nerve endings for touch and pain

Front 23

What are the five types of cells in the epidermis?

Back 23

stem cells

keratinocytes

melanocytes --> occur only in stratum basale

tactile (Merkel) cells --> in basal layer

dendritic (Langerhans) cells --> found in stratum spinosum and granulosum

Front 24

What is the role of dendritic (Lanfgerhans) cells?

Back 24

macrophages originating in bone marrow that guard against pathogens; stand guard against toxins, microbes, and other pathogens that penetrate skin

found in stratum spinosum and granulosum

Front 25

What is the role of tactile (Merkel) cells?

Back 25

touch receptor cells associated with dermal nerve fibers

found in basal layer of epidermis

Front 26

Which layer of the epidermis is a single layer of cuboidal to low columnar stem cells and keratinocytes resting on the basement membrane?

Back 26

stratum basale

melanocytes and tactile cells are scattered among the stem cells and keratinocytes

Front 27

What does the division of stem cells of stratum basale give rise to?

Back 27

keratinocytes that migrate towards the skin surface and replace lost epidermal cells

Front 28

Which layer of the epidermis produces more and more keratin filaments which causes the cell to flatten and consists of dendritic cells throughout the stratum?

Back 28

stratum spinosum

named for artificial appearance created in histological section

numerous desmosomes and cell shrinkage produces spiny appearance

consists of several layers of keratinocytes

Front 29

Which layer of the epidermis consists of 3-5 layers of flat keratinocytes and contains dark-staining keratohyalin granules?

Back 29

stratum granulosum

Front 30

Which layer of the epidermis consists of up to 30 layers of dead, scaly, keratinized cells that form a duable surface layer, and is resistant to abrasion, penetration, and water loss?

Back 30

stratum corneum

Front 31

Which layer of the epidermis is seen only in thick skin, is a thin translucent zone superficial to stratum granulosum, keratinocytes are densely packed with eledin, and cells have no nucleus or other organelles?

Back 31

stratum lucidum

zone has a pale, featureless appearance with indistinct boundaries

Front 32

Where are keratinocytes produced?

Back 32

deep in the epidermis by stem cells in stratum basale

Front 33

What does mitosis require an abundant supply of?

Back 33

oxygen and nutrients

Deep cells acquire oxygen from blood vessels in nearby dermis.

Once epidermal cells migrate more than 2 or 3 cells away from the dermis, their mitosis ceases.

Front 34

Newly formed keratinocytes push the older ones toward the surface. What occurs in 30-40 days?

Back 34

a keratinocyte makes its way to the skin surface and flakes off

slower in old age
faster in injured or stressed skin

Front 35

What are calluses or corns?

Back 35

thick accumulations of dead keratinocytes on the hands or feet

Front 36

What 3 important keratinocyte developments occur in the stratum granulosum?

Back 36

Keratinocyte nucleus and other organelles degenerate; cells die.

Keratohyalin granules release a protein filagrin; binds the keratin filaments together into coarse, tough bundles

membrane-coating vesicles release lipid mixture that spreads out over cell surface and waterproofs it

Front 37

Where does the epidermal water barrier form?

Back 37

between stratum granulosum and stratum spinosum

Front 38

What is the keratinocyte critical for?

Back 38

retaining water in the body and preventing dehydration

Front 39

Why do cells above the water barrier die quickly?

Back 39

barrier cuts them off from nutrients below

dead cells exfoliate (dander)

dandruff: clumps of dander stuck together by sebum (oil)

Front 40

What do keratinocytes consist of?

Back 40

lipids secreted by keratinocytes
tight junctions between keratinocytes
thick layer of insoluble protein on the inner surfaces of the keratinocyte

Front 41

Which epithelium is composed mainly of collagen with elastic fibers, reticular fibers, and fibroblasts and is well supplied with blood vessels, sweat glands, sebaceous glands, and nerve endings?

Back 41

dermis --> 0.2 mm (eyelids) - 4 mm (palms, soles)

Front 42

What are upward fingerlike extensions of the dermis?

Back 42

dermal papillae

friction ridges on fingertips that leave fingerprints

Front 43

Hair follicles and nail roots are embedded in the ____________.

Back 43

dermis

Smooth muscle (piloerector muscles) associated with hair follicles.

Front 44

In what way does smooth muscle (associated with hair follicles) respond to stimuli?

Back 44

contract in response to stimuli such as cold, fear, and touch (goose bumps)

Front 45

Which layer of the dermis is the superficial zone that is a thin zone of areolar tissue, near the dermal papilla, allows for mobility of leukocytes and other defense cells should epidermis become broken, and is rich in small blood vessels?

Back 45

papillary layer

Front 46

Which layer of the dermis is the deeper and thicker layer that consists of dense, irregular connective tissue?

Back 46

reticular layer

stretch marks (striae) tears in the collagen fibers caused by stretching of the skin due to pregnancy or obesity

Front 47

Which form of epithelium is subcutaneous tissue that has more areolar and adipose than dermis, pads the body, and binds skin to underlying tissues?

Back 47

hypodermis

drugs introduced by injection --> hypodermis is highly vascular and absorbs them quickly

subcutaneous fat

Front 48

What is the role of subcutaneous fat?

Back 48

energy reservoir
thermal insulation

8% thicker in women

Front 49

What is the most significant factor in skin color that accumulates in the keratinocytes of stratum basale and stratum spinosum?

Back 49

melanin --> produced by melanocytes

Eumaelanin - brownish black
Pheomelanin - a reddish yellow sulfur-containing pigment

Front 50

People of different skin colors have the same number of ____________.

Back 50

melanocytes

Front 51

Describe the melanin of dark-skinned people.

Back 51

produce greater quantities of melanin

melanin granules in keratinocytes are more spread out rather than tightly clumped

melanin breaks down more slowly

melanized cells seen throughout the epidermis

Front 52

Describe the melanin of light-skinned people.

Back 52

melanin is clumped near keratinocyte nucleus

melanin breaks down more rapidly

little melanin seen beyond stratum basale

The amount of melanin also varies with exposure to ultraviolet (UV) rays of sunlight.

Front 53

What is the red pigment of red blood cells that adds reddish to pinkish hue to skin?

Back 53

hemoglobin

Front 54

What is the yellow pigment acquired from egg yolks and yellow/orange vegetables?

Back 54

carotene --> concentrates in stratum corneum and subcutaneous fat

Front 55

How does cyanosis-blueness of the skin arise?

Back 55

from deficiency of oxygen in the circulating blood

airway obstruction (drowning or choking)
lung diseases (emphysema or respiratory arrest)
cold weather or cardiac arrest

Front 56

What is the abnormal redness of the skin due to dilated cutaneous vessels and how does it arise?

Back 56

erythema

exercise, hot weather, sunburn, anger, or embarrassment

Front 57

What is pale or ashen color when there is so little blood flow through the skin that the white color of dermal collagen is visible and how does it arise?

Back 57

pallor

emotional stress, low blood pressure, circulatory shock, cold, anemia

Front 58

What is the genetic lack of melanin that results in white hair, pale skin, and pink eyes? How does it arise?

Back 58

albinism

have inherited recessive, nonfunctional tyrosinase allele

Front 59

What is the yellowing of skin and sclera due to excess bilirubin in the blood?

Back 59

jaundice

cancer, hepatitis, cirrhosis, other compromised liver function

Front 60

What is the mass of clotted blood showing through skin?

Back 60

hematoma (bruise)

Front 61

Skin color is one of the most conspicuous signs of human variation. How does it arise?

Back 61

results from combination of evolutionary selection pressures

especially differences in exposure to ultraviolet radiation (UVR).

Front 62

What are the two adverse effects of UVR?

Back 62

causes skin cancer

breaks down folic acid needed for normal cell division, fertility, and fetal development

Front 63

What is the one desirable effect of UVR?

Back 63

stimulates synthesis of vitamin D necessary for dietary for calcium absorption

Front 64

Ancestral skin color is a compromise between ___________ and _______________ requirements.

Back 64

vitamin D and folic acid

Women have skin averaging about 4% lighter than men. Women need greater amounts of vitamin D and folic acid to support pregnancy and lactation.

Front 65

High altitude and dry air _______________ skin pigmentation.

Back 65

increases

Andes, Tibet, Ethiopia

UVR accounts for up to 77% of variation in human skin color.

Front 66

What are the markings on the fingertips that leave oily fingerprints on surfaces we touch?

Back 66

friction ridges --> allow manipulation of small objects

Front 67

What are the lines on the flexor surfaces of the digits, palms, wrists, and elbows that marks the sites where the skin folds during flexion of the joints?

Back 67

flexion lines (flexion creases)

Front 68

What changes should be watched in moles?

Back 68

color, diameter, or contour

may suggest malignancy (skin cancer)

Front 69

What are patches of discolored skin caused by benign tumors of dermal blood capillaries?

Back 69

hemangiomas (birthmarks)

capillary hemangiomas, cavernous hemangiomas, port-wine stain

Front 70

What are hair and nails mostly composed of?

Back 70

dead, keratinized cells (compact hard keratin)

tougher and more compact than pliable soft keratin that makes up stratum corneum of skin due to numerous cross-linkages between keratin molecules

Front 71

Limbs and trunk have ________ hairs per cm squared.

Back 71

55-70

Front 72

What is the fine, downy, unpigmented hair that appears on the fetus in the last 3 months of development?

Back 72

lanugo

Front 73

What is the fine hair that replaces lanugo by time of birth?

Back 73

vellus

2/3 of the hair of women
1/10 of the hair of men

All of the hair of children except eyebrows, eyelashes, and hair of the scalp.

Front 74

What is longer, coarser hair that is usually more heavily pigmented?

Back 74

terminal

forms eyebrows, eyelashes, and the hair of the scalp
after puberty forms the axillary and pubic hair
male facial hair and some of the hair on the trunk and limbs

Front 75

What is a swelling at the base where hair originates in dermis of hypodermis?

Back 75

bulb --> only living hair cells are in or near bulb

Front 76

What is the remainder of the hair in the follicle?

Back 76

root

Front 77

What is the portion of hair above the skin surface?

Back 77

shaft

Front 78

What is the bud of vascular connective tissue that is encased by the bulb and provides the hair with its sole source of nutrition?

Back 78

dermal papilla

Front 79

What is the region of mitotically active cells immediately above papilla in the hair's growth center?

Back 79

hair matrix

Front 80

Which layer of the hair is a core of loosely arranged cells and air spaces?

Back 80

medulla

Front 81

Which layer of the hair constitutes the bulk of the hair and consists of several layers of elongated keratinized cells?

Back 81

cortex

Front 82

Which layer of the hair is composed of multiple layer of very thin, scaly cells that overlap each other and free edges are directed upward?

Back 82

cuticle

Front 83

Describe the textures of hair.

Back 83

straight hair is round

wavy hair is oval

curly hair is relatively flat

Front 84

Describe brown and black hair.

Back 84

rich in eumelanin

Front 85

Describe red hair.

Back 85

has a slight amount of eumelanin but a high concentration of pheomelanin

Front 86

Describe blond hair.

Back 86

has an intermediate amount of pheomelanin and very little eumelanin

Front 87

Describe gray and white hair.

Back 87

results from scarcity or absence of melanin in the cortex and the presence of air in the medulla

Front 88

What does hair color arise from?

Back 88

pigment granules in the cells of the cortex

Front 89

What hair follicle is the extension of the epidermis that lies immediately adjacent to hair root and toward the deep end widens into bulge?

Back 89

epithelial root sheath

a bulge is a source of stem cells for follicular growth

Front 90

What hair follicle is derived from dermis that surrounds the epithelial root sheath and is denser than adjacent connective tissue?

Back 90

connective tissue root sheath

Front 91

What are nerve fibers that entwine each follicle and respond to hair movement?

Back 91

hair receptors

Front 92

What are bundles of smooth muscle cells and extends from dermal collagen to connective tissue root sheath, and causes goose bumps?

Back 92

piloerector muscle (arrector pili)

Front 93

Describe the hair cycle.

Back 93

Anagen: growth stage; 90% of scalp follicles at any given time

Catagen: degenerative stage; mitosis in the hair matrix ceases and sheath cells below the bulge die

Telogen: resting stage when papilla reaches the bulb

Front 94

When may club hair fall out?

Back 94

during catagen or telogen

or be pushed out by new hair in the next anagen phase

Front 95

Describe the anagen hair stage.

Back 95

stem cells multiply and travel downward, pushing dermal papilla deeper into skin, forming epidermal root sheath

sheath cells transform into hair cells, synthesize keratin and die as they are pushed upward

new hair grows up the follicle, often alongside of an old club hair from the previous cycle

Front 96

Describe the catagen hair stage.

Back 96

follicle shrinks and dermal papilla is drawn up toward the bulge

base of hair keratinizes into hard club (club hair) that loses its anchorage and is easily pulled out by brushing

Front 97

Describe the telogen hair stage.

Back 97

resting stage when papilla reaches the bulge

Front 98

What is the condition in which hair loss occurs from specific regions of the scalp rather than thinning uniformly?

Back 98

pattern baldness

combination of genetic and hormonal influence

baldness allele is dominant males and expressed only in high testosterone levels

Front 99

What does testosterone cause terminal hair to be replaced with?

Back 99

vellus hair

Front 100

What are clear, hard derivatives of the stratum corneum?

Back 100

fingernails and toenails

composed of very thin, dead cells packed with hard keratin

Front 101

Most hair on trunk and limbs is __________.

Back 101

vestigial --> little present function, warmth in ancestors

Front 102

What alerts us of parasites crawling on skin?

Back 102

hair receptors

Front 103

Describe the nail plate.

Back 103

hard part of the nail

free edge: overhangs the fingertip
nail body: visible attached part of the nail
nail root: extends proximally under overlying skin

Front 104

Eyelashes and eyebrows provide _____________________.

Back 104

nonverbal communication

Front 105

What do guard hairs protect?

Back 105

nostrils and ear canals

Front 106

What is the surrounding skin rising a bit above the nail?

Back 106

nail fold

Front 107

What separates the nail fold from nail?

Back 107

nail groove

Front 108

What skin underlies the nail plate?

Back 108

nail bed

Front 109

What is the epidermis of the nail bed?

Back 109

hyponychium

Front 110

What is an opaque white crescent at proximal end of nail?

Back 110

lunule

Front 111

What is the narrow zone of dead skin that commonly overhangs this end of the nail?

Back 111

eponychium (cuticle)

Front 112

What are the most numerous skin glands in adult skin that consist of simple tubular glands, and secretes watery perspiration that cools the body?

Back 112

merocrine (eccrine) sweat glands

Front 113

What sweat glands occur in the groin, anal region, axilla, areola, and bearded area in mature males, ducts lead to nearby hair follicles, produce sweat that is thicker, milky, and contains fatty acids?

Back 113

apocrine sweat glands

scent glands that respond to stress and sexual stimulation

develop at puberty

Front 114

What are chemicals that influence the physiology of behavior of other members of the species?

Back 114

pheromones

Front 115

What is the disagreeable body odor produced by bacterial action on fatty acids?

Back 115

bromhidrosis

Front 116

How does sweat begin?

Back 116

as a protein-free filtrate of blood plasma produced by deep secretory portion of gland

potassium ions, urea, lactic acid, ammonia, and some sodium chloride remain in the sweat, most sodium chloride reabsorbed by duct

Front 117

Describe the composition of sweat.

Back 117

99% water with pH range of 4-6

acid mantle inhibits bacterial growth

Front 118

Which form of sweat does not produce visible wetness of skin?

Back 118

insensible perspiration (500 mL/day)

Front 119

Which form of sweat produces wetness of skin?

Back 119

diaphoresis (with exercise--may lose 1 L of sweat per hour)

Front 120

Holocrine glands secrete ______________ cells.

Back 120

broken-down cells that are replaced by mitosis at base of gland

Front 121

Which glands keep skin and hair from becoming dry, brittle, and cracked?

Back 121

sebaceous glands

Front 122

Which glands are found only in the external ear canal?

Back 122

ceruminous glands --> simple coiled tubular glands with ducts that lead to skin surface

Their secretion combines with sebum and dead epithelial cells to form earwax (cerumen).

keeps eardrum pliable
waterproofs the canal
kills bacteria
makes guard hairs of ear sticky to help block foreign particles from entering auditory canal

Front 123

What are milk-producing glands that develop only during pregnancy and lactation?

Back 123

mammary glands --> modified apocrine sweat glands

Front 124

What is the disorder of additional nipples?

Back 124

polythelia

Front 125

Where is skin cancer most commonly found?

Back 125

head and neck

Most common in fair-skinned people and the elderly.

Front 126

What is the most common type of skin cancer that is the least dangerous because it seldom metastasizes, and consists of a small, shiny bump with central depression and beaded edges?

Back 126

basal cell carcinoma --> forms from cells in stratum basale

Front 127

Which form of skin cancer arises from keratinocytes from stratum spinosa in which lesions usually appear on scalp, ears, lower lip, or back of the hand and have raised, reddened, scaly appearance later forming a concave ulcer?

Back 127

squamous cell carcinoma --> tends to metastasize to lymph nodes and may become lethal

Front 128

Which form of skin cancer arises from melanocytes often in a preexisting mole, accounts for less than 5% of skin cancers but is the most deadliest form, and metastasizes rapidly?

Back 128

malignant melanoma --> unresponsive to chemotherapy; usually fatal

Front 129

How do deaths primarily result from burns?

Back 129

fluid loss, infection, and toxic effects of eschar (burned, dead tissue)

Front 130

What is the removal of eschar?

Back 130

debridement

Front 131

What degree of burn is a partial-thickness burn that involves only the epidermis and is marked by redness, slight edema, and pain?

Back 131

first-degree burn --> heals in a few days

Front 132

What degree of burn is a partial-thickness burn that involves the epidermis and part of the dermis, leaves the dermis intact, red, tan, or white, and is blistered and very painful?

Back 132

second-degree burn --> two weeks to several months to heal and may leave scars

Front 133

What degree of burn is a full-thickness burn, destroys the epidermis and all of the dermis, as well as deeper tissues (muscles or bones), and often requires skin grafts?

Back 133

third-degree burn --> needs fluid replacement and infection control

Front 134

Which form of graft is tissue taken from another location on the same person's body?

Back 134

autograft

Front 135

Which form of graft is skin from an identical twin?

Back 135

isograft