口腔生理学术语(E)

1、口腔生理学术语（E）口腔生理学术语（E） 口腔生理学术语（E） ecological balanee - astable balanee in the numbers of each species in an ecosystem. in the ecosystem of the mouth this balanee is brought about by competiti on and cooperati on betwee n the different organismand the hosts defences which tend tocon trol populati on si

2、ze.ecosystem - a stable environment in which live a large number of different forms of life, each affecting the other. example are a forest, desert, tidal area, soil, oral cavity, gut.ectoderm - the outer of the three cell layers which form, as the clump of early embry onic cells begi ns to differe

3、ntiate. the ectoderm will form the epidermis of the skin and the n ervous system. the other two layers are the mesoderm and the en doderm.ectomese nchyme - a n ame give n to den tal mese nchyme which reflects its partly ectodermal origi n.eicosa no ids - are a class of horm ones which are all made f

4、rom phospholipids. theyin cludeprostagla ndins, thromboxa nes, and leucotrie ns.ielastic fibres -are long, thi n, ribb on s-likefibres,sometimes even sheet-like. they are composed of a central core of elast in, a rubbery prote in, surro un ded by glycoprote inmicrofilame ntsi.elastinis foundall over

5、 thebodybutparticularlyin the wallsof bloodvessels and inourvocalchords.electr on-the negatively charged elements (of anatomwhich circlethe nu cleusif anelectronis losttheatombecomes arelatively positivelycharged ion. ithasbee nioni sed .electr ontran sportsystemhydroge nionsproducedduri ng the3 pre

6、paratorystepsof aerobic respirationarecarried byni coti namideade ninedinu cleotide(n ad).thehydroge n ion plus one electro n form n adh, which is take n to the electro n tran sport system. this tran sport system is run by a series of 5 molecules. the first, removes the two electro ns from n adh,( o

7、ne comes from the hydroge n atom, leav ing behi nd a hydrogen ion), these two electrons, bounce from the first molecule in the transportsystem to the second, third, forthand the n last one, cytochrome oxidase, which fin ally places the electr ons onto oxyge n gas o2. the electr on rich oxyge n atoms

8、 are attractive to the hydroge n ions and they comb ine to formwater. (oxygen in the process of aerobicrespirationactstherefore as an electr on acceptor). in the process of bouncingdow nhillthe electrons have released sufficient energy topower upa smallbattery. thisbatteryhas been madebypump inghydr

9、oge nions out ofthe inner membrane ofthemitocho ndria. the collecti on of hydroge n ions outside, piles upand their electrical pressure mounts. they want to get back across the membra ne, and are allowed, one at a time to pass back through the en zyme atp syn thase. this en zyme sits like a water wh

10、eel in the cell membra ne, tur ned by the passage of hydrogen ions. its turning wheel builds an atp molecule in every turn. the wheel may be going at about 200 revoluti ons per second, powering the synthesis of an atp molecule with each turn. atp formed in this way takes a while but can be susta ine

11、d to fuel the body duri ng aerobic exercise. whe n the dema nd for power exceeds this rate, the cells have to rely on an aerobic respirati on.electrostatic - a force gen erated by differe nces in electric charge of two particles.enamel prisms - rod-likebundlesof hydroxyapatiecrystals which are orien

12、tatedat right angles to the toothsurface. each prism can be traced from the outside of theen amel all the way to the dentine jun cti on.en amel -the outerlayerhard layerwhichcoversthedentinearoundthe crown ofa tooth. enamelcon sistsofcloselypackedcrystalsof hydroxyapatitewithvery littleorga nic mate

13、rial. a recog ni sable un it of structure in en amel is the en amel prism.en ameloid - a type of en amel found in fish and reptiles inwhich the en amel prisms are haphazardly arra nged; in con trasten amel prism are parallel to each other and orie ntated at rightan gle to the tooth surface.endocrine

14、 glands - the secretion passes into the blood stream, like in suli n, epin ephri ne.en doderm - the inner of the three cell layers which form,as the clump of early embry onic cells begi ns to differe ntiate.the endoderm will formthe gut system and its associatedorgans. the othertwolayersare the meso

15、dermandtheectoderm.en doplasmicreticulum-a system ofinnercellmembra nes which is continu ous with the nu clear membra ne.it tra nsports products of cell syn thesis to the golgi apparatus.described as rough endoplasmicreticulum when there are many ribosomes attached. en dorph ins - a n europeptide wh

16、ich has specific bindingsites on n erve cells called opiate receptors. whe n the receptoris activated by endorphinsor morphineit reduces theexcitability of the post syn aptic cell. peptide receptors are also found on lymphocytes which suggest an associati on betwee n n europeptides and the regulati

17、on of the immune resp on se.endosteum - a layer of bone forming cells, osteoblasts which covers the entire surface of the internal aspect of cortical and spongy bone, separati ng it from the surro unding conn ective tissue. see also bone membra ne.en dothelial cells - the epithelial cells of the en

18、dotheliumwhich lines blood vessels. the cells are flatte ned in to a pavement stone shape and are usually two or three layers thick.en dotox ins - the contents and cell wallsof dead bacteriawhich may be toxic to the host.en kephali ns- similar in structure andacti on toen dorphi ns.environment- desc

19、ribesthe surroundingsin whichorga ni sms live. some physical features of an en vir onment are fairly stable, like trees, rivers, mountains, houses, soil, teeth. some physical features are cha ngeable, like wind, water, light, ph, food supply. others features are less predictable, such asthe balanee

20、in the communityof collaborators, competitorsand parasites. all forms of life in cludi ng bacteria in the mouth, have an en vir onment, which has an importa nt in flue nee on their survival. successful orga ni sms man age to exploit their en vir onment to the best adva ntage or to adapt to it, perha

21、ps only after several generations, if it becomes a serious challe nge to the species.enzyme - a protein that controls and helps a chemical reactionto take place, but is not used up in the process.usually each enzyme is specific for a particular step in a reacti on.en zymesare sen sitive to theiren v

22、ir onment,especially to excessive temperature or ph.epidermal growth factor - a cytokine that stimulates epithelial cell proliferati on.epin ephri ne - a n eurotra nsmitter substa nee found at alladre nergic syn apses (nor epin ephri ne or epin ephri ne). it is the most com monn eurotra nsmitterin t

23、he n ervous system, inparticular at gan gli on cells of the sympathetic n ervous system.epitaxy - the in itiati on of crystalformatio n in a saturatedsolution by providing a template against which crystal can form. there are specific sites on collagen molecules which appear to fun cti on as template

24、s aga inst which hydroxyapatite crystals form.epithelial attachment- the cuff of junctionalepitheliumwhich joi ns the gi ngival sulcus epithelium to the en amel of the tooth. apical migrationof the epitheliumdown onto thecementummay occur due to ageing or periodontal disease.loss of attachme nt prod

25、uces a periodo ntal pocket and a new habitat for an aerobic oral bacteria.epithelium - a layer of cells which forms ali ning for a tube or the coveri ng for an orga n or the whole body.eucaryote - a cell in which the geneticmaterial isconfined to the nu cleus, in disti ncti on to a procaryote in whi

26、ch the genetic material is dispersed throughout the cell. other disti ncti ons of eucarytoic cells are the prese nee of orga nelles such as the golgi apparatus, en doplasmic reticulum, lysosomes and mitocho ndriaexocrine glands - the secretion passes intoa duct like sweat, saliva and mucous.ext inct - a pla nt or animal species may en tirely cease to exist. recent examples are the dodo, a large flightless bird which used to live as rece ntly as two hun dred years ago, on the isla nd of mauritius. there are today many species of