1
Q
largest organ of the body that forms a physical barrier between the external environment and the internal environment that it serves to protect and maintain.
A
integumentary system
2
Q
components of integumentary system
A
skin
nails
hair
cutaneous sense organs and glands
3
Q
2 major tissue layers of the skin
A
epidermis and dermis
4
Q
- superficial layer
- stratified squamous epithelium
- cornified or keratinized (hardened by keratin) to prevent water loss
- avascular
- most cells are keratinocytes
A
epidermis
5
Q
prevents water loss and resists abrasion
A
epidermis
6
Q
- dense connective tissue
- vascular
- 10-20 times thicker than the epidermis
- layer of dense connective tissue depending on location
(blood vessels, oil and sweat glands, nerves, hair follicles, and other structures)
A
dermis
7
Q
- responsible for most of the skin’s structural strength
- skin rests on the subcutaneous tissue, which is a layer of connective tissue
(ex. areolar, adipose) - not part of the skin, but it connects skin to underlying muscle or bone
A
dermis
8
Q
- functions as padding and insulation
- acceptable percentage of body fat varies from 21% to 30% for females and 13-25% for males
A
dermis
9
Q
- cells are dead
- represented only by flat membranous sacs filled with keratin
- glycolipids in extracellular space
A
stratum corneum
10
Q
- cells are flattened
- organelles are deteriorating
- cytoplasm full of granules
A
stratum granulosum
11
Q
- cells contain thick bundles of intermediate filaments made of pre-keratin
A
stratum spinosum
12
Q
- cells are actively dividing stem cells
- some newly formed cells become part of the more superficial layers
A
stratum basale
13
Q
dermis consists of
A
sensory nerve ending
melanin granules
melanocytes
14
Q
excessive sloughing of stratum corneum cells from the surface of the scalp is called
A
dandruff
15
Q
in skin subjected to friction, the number of layers in the stratum corneum greatly increases, producing a thickened area called
A
callus
16
Q
keratinization is also called
A
cornification
17
Q
keratinocytes proliferate in the
A
basal layer (mitosis)
18
Q
a complex process that results in the production of the impermeable stratum corneum
A
terminal differentiation (keratinization)
19
Q
LAYERS OF THE EPIDERMIS
thick hairless layer
A
- stratum corneum
- stratum lucidum
- stratum granulosum
- stratum spinosum
- stratum basale
dermis
20
Q
- deepest layer of epidermis
- lies next to dermis
- wavy borderline with the dermis anchors the two together
A
stratum basale (stratum germinativum)
21
Q
- cells undergoing mitosis
- daughter cells are pushed upward to become the more superficial layers
A
stratum basale (stratum germinativum)
22
Q
- several layers thick
- contain a weblike system of intermediate filaments
A
stratum spinosum (pricky layer)
23
Q
- 4-6 layers thick
- accumulates two types of granules: KERATOHYALINE GRANULES and LAMELLAR GRANULES
A
stratum granulosum (granular layer)
24
Q
help to form keratin in the upper layer
A
keratohyaline granules
25
contain water-resistant glycolipid for slowing water loss across the epidermis
lamellar granules
26
- formed from dead cells of the deeper strata
- occurs only in thick, hairless skin of the palms of the hands and soles of the feet
stratum lucidum (clear layer)
27
- outermost layer of the epidermis
- shingle-like dead cells are filled with keratin (protective protein prevents water loss from the skin)
stratum corneum (horny layer)
28
over a bony prominence, the stratum corneum can thicken to form a cone-shaped structure called a
corn
29
Why is it that soles and palms have no hair?
1. Grip and traction
2. sensitivity
3. hygiene
4. heat regulation
30
- palms of hands, soles of feet
- 5 epidermal layers (including stratum lucidum)
- protective, withstands friction and wear
- no hair follicles or sebaceous (oil) glands
thick skin
31
- rest of the body
- 4 epidermal layers, w/o stratum lucidum
- sensory perception, touch, and temperature sensitivity
- contains hair follicles, sebaceous glands, and sweat glands
thin skin
32
cells in the epidermis
1. keratinocytes
2. melanocytes
3. dendritic (Langerhans) cells or intraepidermal cells
4. tactile (Merkel) cells
33
- produce keratin, a fibrous protein that helps give the epidermis its protective properties
- arise in the deepest part of the epidermis, stratum basale
keratinocytes
34
- spider-shaped epithelial cells
- synthesize melanin pigment
- found in the deepest part of the epidermis
melanocytes
35
arise from bone marrow and migrate to the epidermis
- ingest foreign substances
- key activators of our immune system
dendritic (Langerhans) cells or intraepidermal cells
36
- present at the epidermal-dermal junction
- functions as sensory receptor for touch
tactile (Merkel) cells
37
layers of the dermis
epidermis
papillary layer of dermis
reticular layer of dermis
38
2 layers of dermis
papillary dermis (upper dermal region)
reticular dermis
39
- areolar connective tissue
- collagen and elastic fibers form a loosely woven mat
- projections called dermal papillae
--- some contain capillary loops
--- others house pain receptors and touch receptors called tactile or Meissner's corpuscles
papillary layer (upper dermal region)
40
- 80% of the thickness of the dermis
- dense fibrous connective tissue
- cleavage (tension lines): important to surgeon
- flexure lines: dermal folds that occur at or near joints
reticular layer
41
topological lines drawn on a map of the human body
Langer's lines, Langer lines of skin tension, or sometimes called cleavage lines
42
result of a complex interaction between internal and external factors involving the skin
skin tension lines
43
places where the dermis has folds to accommodate joint movement
flexure lines
44
incision made across cleavage lines
- can gap
- increase time needed for healing and result in increased scar tissue formation
45
incision made parallel to cleavage lines
- less gapping
- faster healing, less scar tissue
46
flexure line types
normal palm creases
simian crease
47
normal skin color determinants
melanin
carotene
hemoglobin
48
- polymer made of tyrosine amino acids
- __________: yellow to red
- __________: brown to black
melanin
pheomelanin
eumelanin
49
- precursor of vitamin A needed for vision
- lipid-soluble
- orange to yellow pigment from some vegetables
- accumulates in the stratum corneum and in fatty tissue of hypodermis
carotene
50
_________ is produced by melanocytes and packaged into vesicles called ___________
melanin
melanosomes
51
differences in skin color are due mainly to the amount of pigment the melanocytes produce and transfer to keratinocytes
52
- red coloring from blood cells in dermal capillaries
- Oxygen content determines the extent of red coloring
hemoglobin
53
A decrease in _________, as occurs in shock, can make the skin appear pale.
blood flow
54
A decrease in the _________ produces a bluish color of the skin, called _______.
blood O2 content
cyanosis
55
produced by the golgi apparatus of the melanocyte
melanosomes
56
intracellular organelles that are uniquely generated by pigment cells in the skin and eye
melanosomes
57
Interstitial cell-stimulating hormone, estrogens, melanocyte-stimulating hormone and adrenocorticotrophin appear to increase epidermal melanin by enhancing the activity of _________
tyrosinase
58
skins appear bluish
cyanotic
59
due to embarrassment, inflammation, hypertension, fever, or allergy
redness (erythema)
60
due to emotional stress such as fear, anemia, low blood pressure, impaired blood flow to an area
pallor (blanching)
61
liver disorder, gallbladder, or pancreas; occurs when too much bilirubin builds up in the body
jaundice (yellowing)
62
Vitiligo (skin condition)
depigmentation
63
Addison’s disease (skin disease)
– primary adrenal insufficiency
bronzing (hyperpigmentation)
64
genetic disorder
albinism (partial or complete absence of melanin)
65
hematomas
bruises
66
skin appendages
- cutaneous glands
1. all exocrine glands
2. sebaceous (oil) glands
3. sweat (sudoriferous) glands
- hair
- hair follicles
- nails
67
* Produce oil (sebum), accumulated lipids and cell fragments
- Lubricant for skin
- Prevents brittle hair
- Kills bacteria
* The sebum is released by holocrine secretion
* Most have ducts that empty into hair follicles; others open directly onto skin surface
* Glands are activated at puberty
oil (sebaceous) glands
68
simple, branched acinar glands, with most being connected by a duct to the superficial part of a hair follicle.
sebaceous glands
69
released by holocrine secretion and lubricates the hair and the surface of the skin, which prevents drying and protects against some bacteria.
- oily white substance rich in lipids
sebum
70
produced in the cytoplasm of the cell and released by the rupture of the plasma membrane, w/c destroys the cell and results to secretion
holocrine secretions
71
accumulated sebum blocks a sebaceous gland duct
whitehead
72
material oxidizes and dries
blackhead
73
an active inflammation of sebaceous glands accompanied by “pimples” – caused by bacterial infection (Staphylococcus)
acne
74
overactive sebaceous gland, in infants it is known as “cradle cap”
seborrhea
75
- Produce sweat
- Widely distributed in skin except nipples and parts of external genitalia
2 Types: ______ & _______
sweat (sudoriferous) glands
eccrine and aprocrine
76
- Numerous and abundant in the palms, soles of the feet and forehead
- Open via duct to pore on skin surface
Produce sweat (clear) – water & few salts
Eccrine (Merocrine) sweat glands
77
- Aprox. 2,000 are largely confined to the axillary and anogenital areas
- Ducts empty into hair follicles
- Begin to function at puberty
- Release sweat that also contains fatty acids and proteins (milky/yellowish color)
Apocrine sweat glands
78
term used to classify exocrine glands and their secretions in the study of histology
Merocrine (or eccrine)
79
bud their secretions off through the plasma membrane producing extracellular membrane-bound vesicles.
apocrine
80
COMPOSITION
- Mostly water
- Salts and vitamin C
- Some metabolic waste
- Fatty acids and proteins (apocrine only)
sweat
81
FUNCTION
- Helps dissipate excess heat
- Excretes waste products
- Acidic nature inhibits bacteria growth
sweat
82
from associated bacteria
odor
83
modified apocrine sweat glands
ciliary glands
ceruminous glands
mammary glands
84
Found in the eyelids
ciliary glands
85
- Modified apocrine glands found in the lining of the external ear canal
- Secretion mixes with sebum to produce cerumen or ear wax.
ceruminous glands
86
secretes milk
mammary glands
87
- Produced by hair follicle
- Consists of hard keratinized epithelial cells
- Melanocytes provide pigment for hair color
- Hair grows in the matrix of the hair bulb in stratum basale
hair or pili
88
Dermal and epidermal sheath surround hair root
hair follicle
89
- Smooth muscle cells
- Pulls hairs upright when cold or frightened
- Important role: contractions force sebum out of hair follicles to the skin surface where it acts as skin lubricant.
Arrector pili muscle
90
stage where hair is formed by mitosis of epithelial cells within the hair bulb or hair follicle; these cells divide and undergo keratinization
growth stage
91
hair has stopped growing in this phase, but is still in the hair follicle.
transition stage
92
during this time, hairs are shed from the follicle
resting stage
93
NO HAIR
palms
soles of feet
red part of lips
94
types of hair growth
lanugo
vellus hair
terminal (androgenic) hair
95
- thin, fine hair that grows on most of your body. You might know it as “peach fuzz.”
- usually lighter and shorter than terminal hair.
vellus hair
96
very thin, soft, usually unpigmented downy hair that is sometimes found on the body of a fetal or new-born human, first hair to be produced by the fetal hair follicles
lanugo
97
thicker, longer hair you have on your scalp, which healthcare providers call
terminal (androgenic) hair
98
– excessive hairiness
– may result from an adrenal gland or ovarian tumor
hirsutism
99
hair thinning and some degree of baldness
alopecia
100
Most common, male pattern baldness
True or frank baldness
101
- Scale-like modifications of the epidermis
- Heavily keratinized
- Stratum basale extends beneath the nail bed
- Responsible for growth
- Lack of pigment makes them colorless
nails
CCP 6
flashcards
Decks in class (8)
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