what does the integument include?
skin sweat glands sebaceous gland hair and nails.
what are the function of the skin
protection, body temp regulation, reception, absorption, excretion.
where is thick skin found
palms and soles of feet
where is thin skin found
what does thin skin contain
hair follicle arrector pili muscles, sabaceous glands, sweat glands
what is the epidermis
the epithelial layer of skin contain stratified squamous keratinized
what is the dermis
loose CT dense irregular collagenous ct
which layer is avascular
what are the two cell types of the epidermis
keratinocytes and nonkeratinocytes
what is the diffence between the keratinocytes and the non
the keratinocytes have accumulated keratin filiments renewed at night desquamate every 20-30 days.
in what section of the slide would mitotic division occur in keratinocytes
the basal layer next to the membrane anchored with hemidesmosones
what time of day does mitosis take place in your keratinocytes
in the dark
what are the three types of nonkeratinocytes
langerhands cells merkel cells and melanocytes
what is the role of langerhans cells
defense cells protect from forieng antigens
derived from bone marrow reside in statum spinosum and interact with lymphocytes
what is the role of merkel cells
mechanoreceptors fine detial touch sensation.
found in statum basale form merkel cell neurite complexes with unmyelanated nerve terminals
what is the role of melanocytes
sun umbrellas protect DNA from UV light form melanin
where do langerhans cells derive from
precursors inn the bone marrow go to blood stream then go to epidermis and stratam spinosum
what does a birmeck granule(veriform granules) inside of a langerhans cell look like
vessicle portion connected to a rod like extension
where are merkel cells found in abundance
finger tips and base of hair follicles
where is the merkel cell located
at the basal layer statum basale
what form the merkel cell neurite complexes
merkel cell and unmyelinated nerve terminal
what are melanocytes derived from
the neural crest
what do melanocytes make
where are melanocytes found in a cell
in the stratum basale and superficial dermis
what part of the melanocyte makes tyrosinase
the RER makes it and GA packages it into melanosomes
what parts of the epidermis have more melanocytes
the parts that are more exposed to the light
what causes races to have diffenent skin coloration
the number of melanocytes is the same it’s the activity of tyrosinase numver of melanin granulas sice and distribution and rate of breakdown of the granuals
how does the melanin get into adjecent cells to protect them
the melanocyte has cytoplasmic processes that invade its neighbors and then break down and release the melanin around the side of the nucleus exposed to the light.
what is vitiligo
an autoimmune disease of melanocytes caues skin spots where no melanocyts reside.
what is albinism
melanocyts don’t make melanin due to bad tyrosinase activity
what are the strata of thick skin
stratum corneum, stratum lucidum, stratum granulosum, startum spinosum, stratum basale
what does the stratum corneum do and what are its characteristics
it provides protection, callus fomation, no nuclei or organelles continouse desquamate due to no desmosones
what does the stratum lucidum do and what are characteistics
protection no nuclei or organelles with keratin filiments light staining region
what does the stratum granulosum do and what are the characteristics
water proofing does have nuclei apoptotic nuclear morphology, soft keratine granuels membran coating granules called lamellar bodies
how does the stratum granulosum waterproof
exocytosis of lipid rich substancs form sheets of waterproofing aslo causing starvatoin of superficial layers becaue of lipid membrane that it forms.
what does the stratum spinosum do and what are the characteristics
binding and protection, thick prominent statum interdigitating processes with desmosomes, prickly appearance bundles of intemedialte filomantes cytokeratine (tonofilaments) in cells of upper layers membrane coating franuls lamellar and mitosis in basal layer of the stratum (langerhans cells)
what does the stratum basale do
germinativum, cell renewal achors epidermis to base membrane.
what the characteristics of the stratum basale
single layer of cells desmosones bind to neighboring cells, lots of mitotic activity have hemidesmosones
in stratum spinosum what forms the bridges between the cells
desmosones junctions between to interdigitatin processes of keratinocytes.
what are the layers of thin skin
startum coreum, spinosum, and basale. Startum lucida and granulosa barely there.
what is ichyosis
kyperkeratosis makes you have fish like scales.
what glues the epidermis to the dermis
what are the layers of the dermis that extend into the epidermas and where are they found
dermis papillae and can be found in high mechanical stress areas like soles of feetand palmes (thick skin areas)
what forms our fingerprints
the dermal ridges
what does the dermis do
it provides the nutritional needs of the epidermis
what are the two layers of the dermis
the papillary layer and the reticular layer
what does the papilary layer do and what is it made of
forms the papillae to provide nutrients makde of loose CT reticular fibers elsastic fibers anchoring ribrils VII and meissner corpuscles (mechanorecptors)
what are kreause end bulbs
into what level do 2nd deree burns extend
papillary layer if superfical and reticular if deep.
what is the reticular layer made of
Dense irregular CT type 1 collagen thick elastic fibers proteoglycans fibroblasts, mast cells lymphocytes macrophages fat cells hair follicle arrector pili muscles sebaaceous glands sweat glands
what two types of receptors are found in the reticular layer
pacinian corpuscles detect pressure/vibrations, and ruffini corpuscles are tensile forces numerous in soles of feet.
is the hypodermis part of the skin
no its part of the subcutanous layer superficial facia layer
what do eccrine sweat glands do
thermoregulators found by themselves, simple coiled tubular glandslocatd in deep dermis or hypodermis innervate3d by symphathetic fibers cholinergic endings.
what three things run with hiar
the folliclue eractor pili muscles and the sebaceous glands
what what types of cells make the errine sweat glands
simple cubodial to low colimnar
what type of cells surround the secretory unit
myoepitheial cells help squeeze the sweat out.
where are apoceine sweat glands found
axilla areola and anal region
what activates the apocrine sweat glands
hormones so start at puberty
what activates the function of sebaceous glands
hormones again starts after puberty
what type of secretion method do sebacous cells use
what type of secretion method do apocrine and eccrine cells us
what is the acinus made of in sebaceous glands
the small basal cells immature on the basal lamina and the larger round cells that are degenerating
what is the duct made of in sebacous glands
stratified squamous epithelium
what are the three types of hairs
vellus soft short hair like eyelids, terminal long course on scalp and eybrowns, and lanugo on fetus
what are the parts of the hair follicles
hair root" dermal papilla and matrix" external root sheath, internal root sheath "henlesys outer, huxleuys middle , and cuticle inner layer" and hair shaft "medulla inner, cortex middle, and cuticle outer"
what type of muscles is the arrector pili muscles
what innervates the erctor papillu
be able to identif the nail plate and nail bed
where does nail growth occue
in the nail matrix