Ch5 Flashcards
Integument
bodys largest organ. covers entire body surface (skin)
2 layers of the itegument
epidermis and dermis
epidermis
a layer of the integument. consists of stratified squamous epithelium
dermis
a layer of the epithelium. consists dense irregular and areolar connective tissue
subcutaneous layer or hypodermis
(NOT PART OF INTEGUMENTARY SYSTEM, BUT CLOSELY INVOLVED) a layer deep to the dermin. composed of areolar and adipose connective tissue.
where does the integument meet mucous membranes
nostrils, lips, anus, urethral and vaginal opening. transition and seamless and epithelial defenses remain intact
what are the functions of the integument (7)
protection, provention of water loss/gain, temp regulation, metabolic regulation, immune defense, sensory reception, secretion
how dose integument protect
physcal barrier from injury, chemicals, and light. selectively permeable bc it does still absorb some things
selective permeability
some materails can pass thru
how does integument prevent water loss/gain
epidermis is water resistant so water only exits thru sweat glands.
does succumb to transdermal water loss
transdermal water loss
fluids slowly escape through epidermis to surface where they evaporate
two types of transdermal water loss and definition
insensisble perspiration- release of water vapor from sweat glands even when not sweating
sensible perspiration- visible sweating
what happens when water vapor is release during insensible perspiration
it mixes w sebum and creates a thin acidic film on skin to prevent more water loss and bacterial invasion
how does integument regulate temp (both hot and cold)
vast capillary and sweat glands in the dermis.
blood vessels dilate to dissapate heat if too hot and sweat glands release fluid onto school too cool down through evaporation.
blood vessels constrict when too cold and send blood to deeper body tissues
how does the integument regulate metabolism
when exposed to uv radiation the skin produces cholecalciferol through its epidermal cells which is then coverted to calcitriol which allows us to increase the amount of calcium we absorb from food. this overall helps regulate calcium and phosphate in the blood
what is cholecalciferol and when is it produced
vitamin d3 and produced by epidermal cells when exposed to uv radiation.
what is calcitriol, where is it produced, and and what is it synthesized from
the active form of vitamin d3 and is a hormone. increases absorption of calcium and phosphate from the intestines into the blood, helping us absorb more from our food.
synthesized for cholecalciferol by endocrine cells in kidneys.
how does the integument create immune defense
initiates an immune response in epidermis with epidermal dendritic cells when pathogens penetrate the epidermis. also against epidermal cancer cells
epidermal dendritic cells
play a role in phagocytizing pathogens that have penetrated the epidermis
how does the itegument play a role in sensory reception
sensory neurons in the skin
tactile cells
large specialized epithelial cells that stimulate specfic nerve endings when distorted by fine touch or pressure
what does the integument secrete
sweat
epidermis
the epithelium of the integument. a keratinized stratified squamous epithelium.
layers of the epidermous from deep to superficial
stratum basale, stratum spinosum, stratum granulosum, stratum lucum(in thick skin only), and stratum corneum
which epidermal strata are composed of living keratinocytes and what are the rest made of
basale, spinosum, and granulosum; dead keratinocytes
what cells occupy the stratum basale
keratinocytes, melanocyte, tactile cells
keratinocytes
most abundant cells in epidermis and occur in all strata. get their name from keratin. make epidermous almost waterproof
keratin
in epidermous of skin. fibrous structural proteins that are tough and insoluble. twist around each other to form filaments of they cytoskeleton.
what are keratins found in epidermal cells of skin called
cytokeratins
melanocytes
have long, branching cytoplasmic processes and are scattered among keratinocytes of the stratum basale. produce and store melanin in response to UV expose