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list structural characteristics of epithelial tissue
boundaries b/w diff environments
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list functional characteristics of epithelial tissues
protection, absorption, filtration, secretion, & sensory reception
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describe apical surface
upper free surface exposed to to the body exterior or cavity of sterna organs & may have microvilla/cilia
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describe basal surface
lower attached surface & acts as a filter thru diffusion also where cell migrate thru to repair wounds
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are apical & basal surfaces on all epithelial tissues
yes
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which types of epithelial tissues have microvilli/cilia on their surfaces
simple columnar & psedostratified columnar
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are epithelial tissues able to regenerate
yes
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describe the function of epithelial stem cells
epithelial cells are exposed to friction & are rubbed off or damaged by hostile environments. They regenerate fast as long as they get nutrition
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describe simple squamous epithelial
single layer of flattened cells w/ disc like nuclei & sparse cytoplasm; simplest of the epithelia
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name & classify the epithelial tissues
- simple squamous
- simple cuboidal
- simple columnar
- stratified squamous
- pseudostratified columnar
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function of simple squamous
allows passage of materials by filtration & diffusion; secretes lubricant in serosae
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location of simple squamous
kidney, air sacs in lungs, lining of heart, blood vessels,& lymphatic vessels; ventral body cavity
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describe simple cuboidal
single layer of cubelike cells w/ large, spherical central nuclei
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function of simple cuboidal
secretion & absorption
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location of simple cuboidal
kindey tubules, duct of secretory portions of small glands, ovary surface
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describe simple columnar
single layer of tall cells w/ round nuclei, some bear cilia; layer may contain goblet cells
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location of simple columnar
- nonciliated: lines most of digestive tract, gallbladder, & secretory ducts of glands
- ciliated: lines the branchi, uterine tubes, & some regions of the uterus
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function of simple columnar
absortion; secretion of mucus& enzymes: ciliated type proples mucus or reproductive cells by ciliary action
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describe pseudostratified columnar
single layer of cells of differing height, some not reaching the free surface: nuclei seen at different levels; may contain mucus secreting cells &bear cilia
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location of pseudostratified columnar
- nonciliated: males sperm carrying ducts & ducts of large glands
- ciliated: lines the trachea, most of the upper respiratory tract
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function of pseudostratified columnar
secretion of mostly mucus, propulsion of mucus by ciliary action
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function of stratified squamous
protects underlying tissues in areas subjected to abrasion
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location of stratified squamous
- nonkeratinized: forms the moist linings of esophagus, mouth, & vagina
- keratinized: forms the epidermis of the skin, a dry membrane
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describe stratified squamous
- thick membrane composed of several layers; basal cells are cuboidal &/ columnar & metabolically active; surface cells are flattened (squamous), keratinized:surface cells are full of keratin & dead
- basal cells are active in mitosis & produce the cells of most superficial layers
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which epithelial tissues contain goblet cells and what are their functions
simple columnar
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gland
one/more cells that make & secrete a particular product
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exocrine vs. endocrine glands
- ex: More numerous than endocrine glands.Secrete products into ducts.Secretions released onto body surfaces (skin) or into body cavities
- endo:Ductless glands.Secrete hormones that travel through lymph or blood to target organs
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multicellular vs. unicellular
- uni: mucus & goblet cells; simple glands have unbranched ducts
- multi: 2pts- ducts & secretory unit; compound glands have branched ducts
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how do exocrine glands function (give ex:)
secrete their products onto body surfaces/ into body cavity by exocytosis (unicellular) or via an epithelium walled duct that transports the secretion to the epithelial surface (multi) ex: liver-secrete bile; pancreas-synthesises digestive enzymes
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how do endocrine glands function (give ex:)
- produce hormones that they secret by exocytosis directly into extracellular space. from there they enter the blood/lymphatic fluid & travel to specific organs
- ex: thyroid gland
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indicate common characteristics of connective tissue
- 1. common origin-all CT arrive from embryonic tissue
- 2. degrees of vascularity-cartilage is avascular & dense CT is poorly vascularized
- 3. extracellular matrix-cells separate by nonliving extra cellular matrix( ground substance & fibers)
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list & describe structural elements of connective tissue
- GROUND SUBSTANCE-Substance through which solutes diffuse between blood capillaries and CT cells
- FIBERS- 3types:Collagen (white fibers)Strongest and most abundant type.Provides high tensile strength,elastic-Networks of long, thin, elastin fibers that allow for stretch.Reticular Short, fine, highly branched collagenous fibers
- CELLS-Mitotically active and secretory cells = “-blasts”Mature cells = “-cytes”
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describe the types of connective tissue found in body
- loose ct:areolar, adipose, reticular
- dense ct: dense regular, dense irregular
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describe areolar ct
gel-like marix w/ all 3 fibers: fibroblast, macrophages,mast cells, & some white blood cells
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function of areolar
wraps & cushions organs; its macrophages phagocytize bacteria; plays role in inflammation; holds tissue fluid
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location of areolar
widely distributed under epi of body;forms lamina propria of mucous membranes; packages organs; surrounds capillaries
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describe adipose ct
matrix as in areolar, but very sparse;closely packed adipocytes,fat cells, have nucleus pushed to the side by large fat droplet
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location of adipose ct
under skin in the hypodermis; around kidneys & eyeballs; w/in abdomen & in breast
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function of adipose ct
provides reserve food fuel; insulates against heat loss; support & protects organs
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describe reticular ct
network of reticular fibers in a typical loose ground substance; reticular cells lie on the network
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location of reticular ct
lymphoid organs- lymph nodes, bone marrow, & spleen
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function of reticular ct
fibers form soft internal skeleton that supports other cell types including white blood cells, mast cells, 7 macrophages
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describe dense regular ct
primarily parallel collegan fibers; a few elastic fibers; major cell type is the fibroblast
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location of dense regular ct
tendons, most ligamnets, aponeuroses
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function of dense regular ct
attache muscle to bones/to muscles; attaches bone to bone; w/stands great tensile stress when pulling force is applied in one direction
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describe dense irregular ct
primarily irregularly arranged collagen fibers; some elastic fibers; major cell type is fibroblast
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location of dense irregular ct
fibrous capsules of organs & of joints; dermis of skin; submucosa of digestive tract
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function of dense irregular ct
able to w/stand tension exerted in many directions; provides structural support
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what types of cells are seen in connective tissue
- Fibroblasts in connective tissue proper
- Chondroblasts and chondrocytes in cartilage
- Osteoblasts and osteocytes in bone
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