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what is the integumentary consist of?
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where are glands found?
found in the dermis of the skin which is composed of connective tissue
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the skin is composed of what 2 layers?
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what are the appendages of the skin?
- glands
- arrector pili muscles
- and hairs
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what are the skins nervous structures?
- Meissner's corpuscles
- pacinian corpuscles
- and free nerve endings
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what is the epidermis composed of?
kerartinazed stratified squamous epithelium
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where are keratinocytes found?
they produce a fibrous protein called?
- 1. found in the deepest layers of the epidermis
- 2. keratin
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where are melanocytes found?
what do they produce?
- 1. found in the stratum basale (basal layer) of the epidermis
- 2. produce melanin,a dark skin pigment, it helps protect skin cells from cancerous uv rays
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where are Merkel cells found?
what do they come into contact with?
what are they invovled in?
- found in the stratum basale
- come in contact with sensory neurons
- involved in touch sensation
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what are the langerhan's cells?
where do they migrate to?
- they are macrophage like cells that provide a immune response against foreign cells that invade the body surface
- they migrate from the red bone marrow to the stratum spinosum
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what is the stratum corneum?
- outter most layer of the epidermis
- composed of a tightly packed layer of dead cells heavily kertanized
- layer is very thick in thick skin(palms,or soles of feet)
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what is the stratum lucidum?
- layer of epidermis appears somwhat clear
- most cells are dead
- its greatly reduced in thin skin
- easily seen in thick skin
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what is the stratum granulosum?
- layer of epidermis
- appears granular
- composed of living cells
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what is the stratum spinosum?
- layer of epidermis
- composed of spiny shaped cells
- contains Langerhans's cells
- composed of living cells
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what is the stratum basale?
- innermost layer of the epidermis
- a single cell thick
- the most active cell division occurs here
- contains melanocytes and Merkel cells
- composed of living cells
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how does the epidermis grow?
from the bottom up (like all epithelial tissue)
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the growth of the epidermis?
- mitosis occurs in the stratum basale
- living cells pushed towards the surface
- living cells kertanized flatten and die as they get closer to the surface
- dead cells are sloughed off at the surface
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what is the dermis composed of?
dense irregular connective tissue richly supplied with blood vessels and nerves
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what does the papillary layer contain?
- layer of the dermis
- contains the dermal papillae
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what is the dermal papillae?
- helps hold the epidermis to the dermis
- increases surface area for exchange of nutrients with the epidermis
- contributes to fingerprints
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what is the reticular layer?
- 80% of the thickness of the dermis
- found below the papillary layer
- contains most of the structure of the dermis
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nervous structures of the dermis;
Messner's corpuscles?
Pacinian corpuscles?sensory nerve/free nerve endings?
- 1. found in the dermal papillae involved in light touch sensation
- 2. deep in the dermis sensative to deep pressure
- 3. involved in the sensation of the warmth, coolness, pain, tickling and itching
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what is the hypodermis?
what are its functions?
- "below the skin" also called the superfical fascia
- 1. site for storage of fat
- 2. helps to loosely anchor the skin to mostly muscles
- 3. helps to insulate the body to prevent heat loss
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what three pigments contribute to skin color?
- melanin
- carotene
- hemoglobin
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overview of glnad types?
they are all eithelial in orgin but are found in the underlying connective tissue
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overview of exoccrine glands?
- have a duct
- make an external secretion
- examples are oil and sweat glands of the skin
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overview of endocrine gland?
- do not have a duct
- make an internal secretion
- secrete hormones into the blood to be carries elsewhere in the body
- collectively form the endocrine system
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where are sweat glands located (sudoriferous glands)?
distrubuted over almost the entire body surface
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overview of eccrine sweat glands?
- most numerous type of sweat gland
- produce true sweat in response to:
- elevated temp. nervousness spicy foods,
- composed of simple cubodial epithelium
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properties of the apocrine gland?
- found in the axillary anal and genital areas
- produce a milky or yellowish colored sweat
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what do ceruminous glands produce?
- found in the ears
- produce ear wax
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propeties of sebaceous glands?
- found in all skin except palms and soles of feet.
- produce an oily substance called seabumwhich collects dirt softens and lubricates hair keeps epidermis from crcking kills bacteria and slows water loss
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what is hair composed of?
what are the functions?
- dead kertanized epithelial cells
- sense things that lightly touch the head
- protects the head from direct sunlightin the summer and heatloss in the cold
- eyelashes shield the eyes
- nse hairs filter particles from incoming hair
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shaft vs root?
- shaft is the part coming out of the skins surface
- the root is below
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hair follicle vs the hair?
hair is enclosed in a hair follicle
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cross section:
medulla?
cortex?
cuticle?
hair follicle?
- central core of hair
- surrounds the medulla of the hair
- outtermost layer of the hair
- surrounds the hair
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longitudinal section:
hair matrix?
melanocytes?
hair papilla?
hair follicle?
hair bulb?
- region of high cell divison growing region of hair
- produce pigment of hair
- stimulates hair growth and supplies nutrients to growing hair
- surrounds hair
- expanded end of the hair follicle
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what is teh arrector pili muscle?
- attaches to the hair follicle
- contraction of muscle in response to cold or fear causes the hair to stand erect (goose bumps)
- useful in animals to provide warmth and look dangerous to ememies
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what are the nails composed of?
- like the hair is composed of dead keratinized epithelial cells
- and hard keratin
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free edge?
the most distal part of the nail
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hyponychium?
the area below the free edge of the nail
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nail body?
the visable attached part
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nail root?
the proximal part (embedd in the skin)
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nail matrix?
- the actively growing part of thr nail
- also where the highest mitosis occurs
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lunula?
the white cresent area
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functions of the integumentary system?
- cushions and insulates deeper organs
- protects body from bumps scrapes and cuts
- protects body from chemicals and changes in temp.
- retards water loss
- acts as a mini excretory system
- screens out uv rays from the sun
- contains sensory receptors associated with nerve endings
- makes vitamin D in the presence of sunlight
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temp. regulation:
when bloodvessels in the skin dialate?
when blood vessels constrict?
- blood is shunted to the bodies surface in order to cool the body
- blood is shunted away from the skin therefore maintaining a warmer temp.
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how is the body cooled?
by sweating also called evaporative cooling
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where are stencells found?
in both epithelial and connective tissue of the skin
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4 stages of skin regeneration after energy?
- bleeding occurs at the injury site there is an inflammatory response
- blood clot formedand scab produce macrophages remove debri in the scab fibroblasts invade deeper areas of the injury
- the injury is surrounded by epithelial cells by a week, phagocytes disenagrate the scab
- scab is shed epidermis is complete, fibroblasts continue to create scar tissue
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blister?
caused byshort term but acute trauma resukts in the seperation of teh epidermal and dermal layers by a fluid filled pocket
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what causes freckles and moles?
local accumulations of melanin
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what causes a tan?
melancytes increase their activity when the skin is exposed to sunlight.
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what causes bruises?
reveals where blood escaped from the circulation and clotted beneath the skin
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skin cancer?
a malignent tumor of the skin caused by over exposure to uv rays
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what is a basal cell carcinoma, where does it occur?
- most common skin cancer
- grows very slow
- seldom metastasizes
- occurs in the stratum basale
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squamous cell carcinoma?
- arises in the stratum spinosum
- if caught early and removed the overall cure rate is 99%
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malignent melanoma?
- the most dangerous type of skin cancer
- a cancer of melanocytes often arises from existing moles
- can metastasize very quickly
- early detection is vital
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ABCDE rule of moles/
- assymetry:the 2 sides do not match
- border: the borders have indentations
- color: contains several colors (blk. brown tan blue red.
- diameter: larger than 6mm in diameter the size of a pencil eraser
- elevation: elevated above the skin surface
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wart?
a benign tumor of the skin
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what is a tumor?
an uncontrolled rapid growth of cells
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first degree burn ?
- only the epidermis is damaged
- symptoms are redness swelling pain
- example sunburn
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second degree burn?
- injury to the epidermis and upper dermis
- symptoms like 1st degree but aslo blisters
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third degree burn?
- most serious type
- consumes the entire thickness of the skin
- a skin graft is usually needed
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tattoo?
- temp. tattoo's only color the epidermis
- perm. tattoo color the dermis. the dermis doesnt slough off so it makes it permanent
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what causes acne?
caused by blocked sebaceous glands that have been infected by bacteria
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effects of aging on the integ. system:
- epidermis thins making injury happen more
- melanocytes producton declines leaving eldery pale
- sebaceous gland activity declines leaving skin dry and flaky
- sweat glands less active leaving the elderly prone to overheating
- hair follicels decline causing gray dry hair
- dermis becomes thin less collegan leads to wrinkles
- low blood supply takes longer to repair
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