Anat integumentary Flashcards
epidermis
stratified squamous, no vessels.
dermis
thicker than epidermis connective tissue:collagen&elastic -smooth muscle -nervous -blood -hair follicles -glands
skin basal membrane
anchored to dermis by short fibrils to seperate btw 2 skin layers
subcutaneous layer
under dermis, loose CT and adipose binds skin to underlying
collagen and elastic run parallel to skin . no sharpe injury
has major blood vessels
keratinocytes
old skin cells with cell membranes thickened and developed many demosomes that sticks them to other cell
keratinization
cells form fibrils of keratin and harden. keratin protein made and stored inside cells
layers of epidermis
stratum
corneum: keratinized, dead epithelial, cells flatten/nonucleus
lucidum: clear cells
granulosum: 3-5 layers flattened granular cels, small keratin and nucei
spinosum: layers large nucei and develope keratin
basale: single row cuboidal/columnar divide and grow, melanocytes
skin rubbed regularly
rate of cell division increases
melanocytes
cells in epidermis produces melanin (dark pigment provides skin color)
cytocrine secretion
epidermis has ridges projecting inward
dermis has dermal papillae passing into the spaces btw
dermis extra
mostly irregular dense, elasticity and toughness, thicker than epi.
smooth msucle: testes, hair follicles
skeletal: face
lamellated (pacinian) corpuscles
stimulated by heavy pressure, sensory receproe
tactile (meissner’s) corpuscles
light touch
free nerve ending
respond to temp changing and things that damage tissue
hair
grows, rest, fall
not on palms, soles, lip, nipple, some extern reprod
hair folllicle
tubelike depression, at the base a group of epidermal cells develop hair.
hair rooot
portion of hair embedded in the skin
hair papilla
end of the hair inside the skin
hair development
epidermal cells old pushed to surface and die, its remain is part of the hair shaft (part that is outside).
old hair is pushed outwards and droped off
eumelanin
brownish-black hair color
pheomelanin
blond and red hair
arrector pili muscle
smooth muscle attaches to each hair follicle, when muscle contract the short hair stands-goosebump
nail bed
epithelial continuos with epitheliumof the skin
lunula
most active growing region
Nail plate: keratinized epithelial cells, cell division push
sebaceous glands-holocrine
produce globules of fatty matery material that accumulate, bursting cells: result called sebum n is secreted into hair follicles
not palm and soles
sebum
keeps hair/skin soft, pliable, waterproof,
excess: acne
sweat gland-sudoriferous
ball shaped coil, in deep dermis. sweat secrets by epithelial cells
eccrine gland-type of sweat
respond to high body temp, forehead, neck back,
tube/ducts opens at the surface as a pore. abundant
apocrine gland- sweat
scent, puberty, wet certain are bc emotion, open into hair folllicles
ceremonious gland
secrets ear wax
mamary gland
milk
high temp
active muscle cells release heat, warm blood-brain. dermal vessel dilate, heat of blood carried outside,
deep vessle contract
radiation
infrared heat ray escape warm to cool, rays radiate in all directions
conduction
heat moves from the body directly into the molecules of cooler object in contact with its surface
convection
heat air move away, cold moves toward
evaporation
sweat evaporates, carries heat away from the body
genetic affect skin color
everyone has the same # of melanocytes, diffferent amt of melanin produced, controlled by genes
dark: granules: large, single
environmental factors affect skin color
sunlight, yv light, x-ray, darken melanin stimulate melanocyte to produced pigment
physiological factors affect skin color
blood adds color oxygenated: pink not: bluish vessels dilate: redden contrict: pale carotene yelow
