Chapter 6 PPT Flashcards
Two or more types of tissues grouped together and performing a specialzied functions constitute a
organ
what is the largest organ in body by weight?
skin
skin is also called the
cutaneous membrane
skin is composed of what two layers?
epithelial tissue overlying connective tissue
outer layer of skin is
epidermis
deeper layer of skin is
dermis
epidermis is located in what layer??
outer layer
epidermis contains what type of epithelium?
stratified squamous
epidermis - basement membrane is between
epidermis and dermis
dermis is in what layer?
inner layer
Dermis made up of?
connective tissue
dermis contains
collagenous and elastic fibers
subcutaneous layer also known is
hypodermis
where is subcutaneous layer lcoated at?
beneath dermis, insulating layer
subcutaneous layer composed of
areolar and adipose connective tissue
subcutaneous is not considered to be
part of the skin
subcutaneous layer contains
vessels that supply skin
the epidermis lacks
blood vessels
in the epidermis, the deepest layer is what ?
stratum basale, nourished by blood vessels in dermis
epidermis- as cells grow, they migrate toward
free surface, away from nutrient supply
epidermis - as cells migrate,
older cells ,keratinocytes, begin to flatten and die
what is keratinization?
process of hardening, dehydration, and keratin accumulation that occurs in epidermal cells as they migrate otuwaard
what is keratin?
tough, fibrous, waterproof protein made and stored in cells
as cells reach the otuer surface and become tightly packed, they become the
stratum corneum
what cells are evantually shed from the skin?
stratum corneum
where is the skin thickest at?
palms and soles
most of the body has
thinner epidemris
stratum corneum location?
outermost layer
stratum corneum chaacteristics
many layers of kerantized, dead epithelial cells that are flattened and non-nucleated
stratum lucidum is only present in
thick skin
stratum lucidum location
between stratum corneum and stratum granulosum on soles and palms
stratum lucidum characteristics
cells appear clear; nuclei, organelles, and cell membranes are no longer visible
stratun granulosum location
beneath the stratum corneum
stratum granulosum characteristics
Three to five layers of flattened granular cells that contain shrunken fibers of keratin and shriveled nuclei
stratum spinosum location
beneath the stratum granulosum
stratum spinosum characteristics
Many layers of cells with centrally located, large, oval nuclei and developing fibers of keratin; cells becoming flattened
stratum basal is the
basal cell layer
stratum basale location
deepest layer
stratum basale characteristics
A single row of cuboidal or columnar cells that divide and grow; this layer also includes melanocytes
Function of epidermis
protects against water loss, harmful chmicals, mechanical injury, pathogens
5 layers of epidermis
stratum corneum, lucidum, granulosum, spinosum, basale
where are melanocytes lcoated?
in the stratum basale
what do melanocytes provide?d
dark pigment melanin that absorbs uv light from sunlight and provides skin color
melanin is distributed into
keratinocytes
what do keratinocytes do?
protect skin cells from damaging effects of uv light
What types of factors affect skin color?
Hereditary Factors
Environmental Factors
Physiological Factors
Skin Color - Hereditary factors
All people produces various amounts of melanin, and there is a varying distribution and size of melanin granules
Ski Color - Environment Factors
Sunlight
UV light from sunlamps
X-Rays
Physiological Factors of Skin Color
Oxygenation in blood of dermal blood vessels
Vesodilation/Vasoconstriction of dermal blood vessels
Jaundice
What arises from epithelail cells in skin from tanning?
basal cell carcinoma and squamous cell
whar arise from melaocytes in tanning?
melanomas
melanomas - cancer
least common (4%), but cause 80% of skin cancer deaths
dermis is what layer of skin?
inner
thickness of dermis?
1 to 2 mm thick
dermis contaisn what between epidermal ridges?
dermal papilale
dermis binds what to underlying tissue?
epidermis
dermis is what kidn of layer?
connective tissue
the dermis contaisn what kind of fibers?
muscle
dermis deals with what kind of processes?
nerve cell
dermis - dermal blood vessels supply
nutrients to all skin cells
dermis contains
hair follicles, sweat, and sebaceous gladns
dermis - how is pressure determined?
by lamellated (pacinian) corpuscles
dermis - how is light touch determined?
tactile (meissners) corpuscles
dermis consists of what 2 layers
papillary and reticular layer
the papillar layer is what type of layer
superficial
papillary composed of what type of tissue
areolar connective tissue
the papillary layer is ___ of the 2 layers
thiner
papillary layer of the location of
dermal papillae
recticular layer is what type of layer
deeper
reticular layer is compsoed of
dense irregular connective tissue
reticular layer is ___ of 2 layers
thicekr
what are the accessory structures of the skin
hair follicles
nails
skin glands
what si the nail plate?
overlies nail bed
what si the nail bed
surface of skin, under nail plate
what is a lunula
most active growing region; pale, half-moons shaped region at base of nail plate
what are the 3 parts of the nail?
nail palte
nail bed
lunula
whata re hair follicels
tube-like depression of epidermal cells from which hair develops; extends into dermis or the subcutaneous layer
what are the three parts of hair
hair bulb (dividing cell) hair root hair shaft ()Dead, epidermal cells)
what contains blood vvessels to nourish hair?
hair papilla
hair color is due to
amount of melanin Arrector pili muscle
what is androgenic alopecia?
most common type of baldness, where top of head loses hair
what is hair loss assocaited with?
lower level os testosterone (men) or estrogen (women)
what happens in alopecia areata?
body produces antibodies that attack hair follicles, autoimmune hair loss
sebaceous glands contain what type of glands?
holocrine glands
sebaceous glands usually assocaited with
hair follicles
sebaceous glands produce
sebum, which consists of fatty material, adn cellular debris
subum keeps hair and skin
soft and waterproof
what can excess sebum cause?
acne
sebaceous glands absent on
palms and soles
what is a disorder of sebaceous glands?
acne vulgaris
sweat glands are also called
sudoriferous glands
sweat glands are
wide spread on the skin
sweat glands originate
in deeper dermis or hypodermis as ball shaped coils
eccrine (merocrine) glands are
most numerous
eccrine glands respond to
elevated boduy temperature
apocrine sweat glands appear in the
axilalry and groin areas
apocrine sweat glands secrete by
exocytosis
apocrine sweat glands respond to
emotions, pain
ceruminous glands are
ear wax
mammary glands produce
milk
skin helps produce
vitamin D
set point of body temperature monitored by
hypothalamus
deep body temperatures stays close to
37 degrees celsius or 98.6
when body is too warm, body responds with
vasodilation of dermal blodo vessels and vasoconstriction of deep blood vessels
what are the methods of heat loss
radiation, conduction, convection, evaporation
radiation is
primary method of heat loss, infrared heat rays escape
conduction has heat
move from skin to cooler objects
convection is heat
loss into circulating air currents
evaporation is when
sweat changes into a gas, carries heat away
when body temp rises, thermoreceptors signal
hypothalamus
when body temp rises , what happens to blood vessels?
vasodilation of dermal blood vessels
when body temp rises , sweat gladns are
activates
when body temp falls, thermoreceptors signal
hypothalamsu
when body temp falls, what happens to blood vessels?
vasoconstriction of dermal blood vessels
when body temp falls, sweat gladns are
inactive
when body temp falls, muscles
contract involuntarily (shiver)
what is hyperthermia?
abnormally high body temperature
what is hypothermia
abnormally low body temp
what happens to temperature in a fever?
set point is elevated by the immune system, to fight infection
fever - phagocytes release
pyrogens in response to presence of bacteria, viruses; hypothalamus inceases set poitn adn raises body temp
a clot consists of
fribrin, blood cells, and platelets
clot and dried tissue fluid form
scabs
how is a wound binded together?
fibroblasts secrete colalgen fibers
how is the scab removed?
phagocytic cells remove dead cells and debris, scab sloguhs off
how is a scar formed?
excess colalgenous fibers may form this elevated mass
what is the name of a superfiical, partial-thickness burn
first degree burn
whats damaged in a first degree burn
injuries only epidermis, as in subnurn,
is there scarring in a first degree brun
no
how long to heal first degree burn
days to weeks
what si a deep, partial-thickness burn called
second degree
what is damaged in a second degree burn
destroys epidermis and some dermis, as in burn from hot liquid
what may happen in second degree burn
may blister, healing varies with severity of burn and stem cell survivor
does second degree burns heal?
yes. recovers completely, no scarring
what is a full-thickness burn known as?
third degree
what is damaged in a third degree burn
destroys epidermis, dermis, accessory structures
third degree burns often require
skin grafts, skin substitues
what is the rule of nines for burn patients
divides body surface into regions of 9%, or multiples of 9
burns - cell cycle changes
cell cycle slows, skin becomes scaly, age spots appear
burns - epidermis and dermis becoem
thinner
burns - loss of
fat in subcutaneous layerl person feels cold
burns - what physical change ahppens to skin?
wrinkling, sagging of skin
burns - skin adn oil
sebaceous glands secrete loss oil; skin becomes dry
burns - malanin prioduction
slows, hair whitens
burns - hair
thins
burns - number of hair follicles
decreases
burns - nail growth becoems
impaired
burns - sensory recpetors
decline
burns - body temperature regulation becomes
less effective
burns - diminished ability to produce
vitamin d
