ch. 6 the integumentary system Flashcards
(55 cards)
1
Q
skin and subcutaneou tissue
integumentary system
A
consists of the skin and accessory organs
* hair
* nails
* cutaneous glands
2
Q
skin and subcutaneou tissue
skin is the body’s
A
largest and heaviest organ
* covers 1.5 to; composes 15% of body weight
3
Q
skin and subcutaneou tissue
layers
A
- epidermis stratified squamous epithelium
- dermis deeper connective tissue
- hypodermis connective tissue layer below dermis (not part of skin, associated with it)
4
Q
functions of skin
resistance to
A
trauma and infection
* keratin
* dermacidin and defensins
* acid mantle
5
Q
functions of skin
other barrier functions
A
- water
- UV radiation
- harmful chemicals
6
Q
functions of skin
vitamin D synthesis
A
- skin carries out first step
- liver and kidneys complete process
7
Q
functions of skin
sensation
A
- skin is an extensive sense organ
- receptors for temp, touch, pain, more
8
Q
functions of skin
thermoregualtion
A
- thermoreceptors
- vasoconstriction/vasodilation
- perspiration
9
Q
the epidermis
epidermis
A
keratinized stratified squamous epithelium
10
Q
the epidermis
includes
A
- dead cells at skin surface packed with tough keratin protein
- lacks blood vessels–depends on the diffuiosn of nutrients from underlying connective tissue
- contains sparse nerve endings for touch and pain
11
Q
cells of epidermis
5 cell types
A
- stem cells
- keratinocytes
- melanocytes
- tactile cells
- dendritic cells
12
Q
cells of the epidermis
stem cells
A
- undifferntiated cells that give rise to kertainocytes
- in deepest layer of epidermis (stratum basale)
*
13
Q
cells of the epidermis
keratinocytes
A
- greates majority of epidermal cells
- synthesize keratin
14
Q
cells of the epidermis
melanocytes
A
- synthesize pigment melanin that shields DNA from ultraviolet radiation
- occurs only in stratum basale but have branches processes that spread among keratinocytes and distribute melanin
15
Q
cells of the epidermis
tactile cells
A
- touch receptor cells associated with dermal nerve fibers
- in basal layer of epidermis
16
Q
cells of the epidermis
dendtritic cells
A
- macrophages originating in bone marrow that guard against pathogens
- found in stratum spinosum and granulosm
17
Q
the dermis
dermis
A
connective tissue layer beneath epidermis
18
Q
dermis
composed mainly with
A
collagen
19
Q
dermis
well supplied with
A
- blood vessels
- sweat glands
- sebaceous glands
- nerve endings
20
Q
dermis
has a wavy conspicuous boundary with the
A
superficial epidermis
21
Q
dermis
dermal papillae are
A
upward
finger-like extensions of dermis
22
Q
dermis
epidermal ridges are
A
downward waves of epidermis
23
Q
dermis
prominent waves on
A
fingers produce friction ridges of fingerprints
24
Q
hypodermis
hypodermis
A
- subcutaneous tissue
- has more areolar and adipose than dermis has
- pads body and binds skin to underlying tissues
- common site of drug injection since it has many blood vessels
25
# hypodermis
subcutaneous fat
* energy reservoir
* thermal insulation
* thicken in women
* thinner in infants, elderly
26
# skin color
melanin
most significant factor in skin color
27
# skin color
melanin is produced by
melanocytes
accumulates in keratinocytes
28
# skin color: melanin
two forms of pigment
* eumelanin--brownish black
* pheomelanin--reddish yellow (sulfur containing)
29
# skin color
people of different skin colors have the same
number of melanocytes
30
# skin color
darker skinned people
* produce greater quantities of melanin
* melanin breaks down more slowly
* melanin granules more spread out in keratinocytes
* melanized cells seen throughout the epidermis
31
# skin color
lighter skinned people
* melanin clumped near keratinocyte nucleus
* little melanin seen beyown stratum basale
32
# skin color
exposure to UV light stimulates
melanin secretion and darkens skin
* this color fades as melanin is degraded and old cells exfoliated
33
# skin color
other pigments can influence skin color
* hemoglobin--pigment in RBCs-adds reddish to pinkish hue to skin
* carotene--yellow pigment acquired from egg yolks and yellow/orange vegetables--concentrates in stratum corneum and subcutanous fat
34
# skin color
colors of diagnostic value
* cyanosis
* erythema
* pallor
* albinism
* jaundice
* hematoma
35
# skin color: colors of diagnostic value
cyanosis
blueness due to oxygen deficiency
36
# skin color: colors of diagnostic value
erythema
redness due to increased blood flow to skin
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# skin color: colors of diagnostic value
pallor
palness due to decreased blood flow to skin
38
# skin color: colors of diagnostic value
albinism
milky white skin and blue-gray eyes due to genetic lack of melanin-synthesizing enzyme
39
# skin color: colors of diagnostic value
jaundice
yellowing due to bilirubin in blood (can be caused by compromised liver function)
40
# skin color: colors of diagnostic value
hematoma
bruising
(clotted blood under skin)
41
# skin cancer
skin cancer
most cases causes by UV rays of the sun damaging skin cell DNA
42
# skin cancer
most often on the
* head
* neck
* hands
most common in fair-skinned people and the elderly
one of the most common easily treated cancers
has one of the highest survival rates if detected and treated early
43
# skin cancer
3 types of skin caner names for the epidermial cells in which they orginate
* basal cell carcinoma
* squamous cell carcinoma
* malignant melanoma
44
# skin cancer: basal cell carcinoma
basal cell carcinoma
* most common type
* least dangerous b/c it seldom metastasizes
* forms from cells in stratum basale
* lesion is small shiny bump with central depression and beaded edges
45
# skin cancer: squamous cell carcinoma
squamous cell carcinoma
* arises from keratinocytes of stratum spinosum
* lesions usually on scalp, ears, lower lip, or back of hand
* have raised, reddened scaly appearance later forming a concave ulcer
* chance of recovery good with early detection and surgical removal
* tends to metastasize to lymph nodes and may become lethal
46
# skin cancer: malignant melanoma
malignant melonoma
* skin cancer that arises from melanocytes
* less than 5% of skin cancers but MOST DEALDY form
* can be successfully removed if caught early but if it metasizes it is usually fatal
* greated risk factor: famillial histoey of malignant melanoma
* highest incidence in men, redheads, and people who has severe sunburn as a child
47
# burns
burns
leading cause of accidental death
* fires
* kitchen spills
* sunlight
* ionizing raditation
* strong acids/bases
* electrical shock
48
# burns
deaths result primarily from
* fluid loss
* infection
* toxic effects of eschar (burned, dead tissue)
debridement: removal of eschar
49
# burns
classified according to depth of
tissue involvement
50
# burns
first-degree burns
* involves only epidermis
* redness
* slight edema
* pain
* heals in days
51
# burns
second degree burns
* partial-thickness burn
* involves part of dermis
* may appear red, tan, white
* blistered and painful
* 2 weeks--several months to heal and may leave scars
52
# burns
third degree burns
* full-thickness burn
* involves epidermis, all of dermis, and often some deeper tissues
* often requires skin grafts
* needs fluid replacement, infection control, supplemental nutrition
53
# UV rays and sunscreen
UVA and UVB are improperly called
tanning rays and burning rays
* both thought to initiate skin cancer
* no such thing as a healthy tan
54
# UV rays and sunscreen
sunscreens protect you from
sunburn but unsure if they provide protection against cancer
* high SPF numbers can give false sense of security
* chemical in sunscreen damage DNA and generate harmful free radicals
55
