history history known acid medical use related substances stretches antiquity pure manufactured marketed willow rich plants appear egyptian second millennium referred use tea reduce western medicine classical antiquity middle ages willow bark extract recognized specific effects fever pain mid eighteenth century lewis clark allegedly willow bark tea remedy fever members famous expedition nineteenth century experimenting variety chemicals related acid active component willow extract chemist charles treated produce acid time second half nineteenth century academic established compound chemical structure devised efficient methods synthesis scientists drug firm began investigating acid irritating replacement standard common dubbed drug selling world word brand generic drug rights trademark lost sold countries popularity grew half twentieth century leading fierce competition brands products popularity declined development 1960s 1970s john discovered basic mechanism effects clinical trials studies 1960s 1980s established anti agent reduces risk diseases sales revived considerably decades twentieth century remain strong widespread use treatment heart attacks strokes early history derived willow trees rich plants dating ancient earliest specific reference willow rich plant conditions likely affected anti anti properties comes egyptian medical text likely copy text time tablet willow bark preparations standard western medicine beginning greek physician fifth century recommended ease pain child bearing reduce fever roman suggested willow leaf extract treat signs heat swelling pain willow treatments appeared elder natural history time willow commonly roman arab worlds small large growing botanical 18th 19th centuries major turning point came letter english chaplain edward stone read meeting royal society describing dramatic power willow bark extract cure ill defined symptoms including intermittent fever pain fatigue primarily referred malaria inspired doctrine signatures search treatment near waters known cause stone bark willow tree noticed reminiscent standard expensive cure bark collected dried substantial willow bark years tested number people sick fever letter stone reported consistent success describing willow extract effects identical bark little potent fact active ingredient bark attacked infectious cause malaria active ingredient willow extract relieved symptoms malaria cure stone letter mistakenly attributed edward stone printed philosophical transactions end 18th century willow gaining popularity inexpensive substitute bark 19th century young discipline organic chemistry began grow europe scientists attempted active components including willow bark unsuccessful attempts italian joseph obtained relatively pure crystals following year developed better procedure modest yields swiss discovered thought new pain reducing substance isolated common remedy italian chemist found method obtaining potent acid form willow extract named acid german chemist working identify extract jacob soon realized fact acid found middle decades 19th century use including acid grew considerably physicians increasingly knew expect reduction pain fever unpleasant effects particularly limited 1880s german chemical industry jump started lucrative development coal tar branching investigate potential new tar derived turning point advent company branded version known derivative fever reducing properties discovered accident success inspired head research small firm friedrich company start systematic search chemical fever soon developed followed synthesis taking control overall management began expand company drug research program created group creating new drugs headed university chemist arthur group testing drugs headed beginning periods young chemist joined group key figures development acid drug respective roles subject contention started working find irritating substitute acid generally accepted turned idea father suffering effects taking attempted acid acid charles prepare acid course work synthesis properties acid mixed salt acid vigorous reaction ensued resulting melt soon solidified structural theory existed time called compound obtained tried dissolve solid solution immediately von produced called acid different method reaction acid repeated von acid concluded reactions gave compound acid credited paper conducting experiments assign correct structure group connected oxygen procedure drug company published methods produce pure method efficient useful likely started published methods october according laboratory found better method making acid sent group testing initial results positive step normally clinical trials opposed investigation acid reputation weakening heart possibly effect high treat group soon busy testing chemical success team soon branded heroin heroic feeling gave frustrated rejection went directly berlin representative arrange low profile trials doctors results trials positive reports typical acid complications intervened scheduled testing soon admitted potential decided proceed production wrote report findings new drug omitted mention receive royalties drug testing ineligible patent taken creating years attributed discovery solely controversy primarily responsible development spread twentieth century origin academic research produce commercially insists active ingredient acid synthesized time pure stable form young chemist working historians challenged early accounts synthesis primarily responsible breakthrough shortly death wrote article years claiming told purpose research meaning merely carried research plan drug gone market direction claim later supported research conducted historian walter general secretary international society history subsequently questioned novelty research noting earlier articles discussed controversy detail countered press release stating according records held equal positions supervisor named patent inventor mention left multiple opportunities claim priority claimed received percentage profit sales naming drug derived chemical german acid named plant derived took added typical drug ending easy final round naming proposals circulated came feared remind customers arthur argued meaning good inappropriate usually indicated improvement earlier version similar drug substance known intended use new establish drug new january settled rights sale leadership firmly committed standards ethical drugs opposed patent ethical drugs drugs obtained usually doctor advertising drugs directly consumers considered strongly opposed medical organizations domain patent limited marketing directly doctors production began sent small drug doctors hospitals advising uses encouraging publish drug effects effectiveness positive results came enthusiasm grew sought secure patent trademark possible ineligible patent germany despite accepted briefly decision overturned patented britain filed december united_states patent issued february british patent overturned american patent besieged ultimately upheld faced growing legal illegal competition globally marketed worked cement connection strategy developed switch distributing powder press form distributing standardized complete distinctive cross logo company set american subsidiary converted factory new_york produce american market paying import duties sued patent company attempts hold sales criticism journalists american medical association especially pure food drug act prevented drugs listed united_states listed intentionally convoluted generic acid acid discourage doctors referring world war outbreak world war facing competition major markets local producers german drug firms particularly british market immediately closed german companies british manufacturing meet demand especially supplies necessary synthesis largely explosives manufacture february company use term australian market taken makers nicholas lost short lived exclusive right united_states german control war disrupted links american plant german headquarters shortage threatened reduce production imports atlantic_ocean blocked royal_navy great plot secure production time indirectly aid german war effort german agents united_states orchestrated known great plot price rose point plant forced drastically cut production especially problematic new branding strategy preparation patent united_states thomas needed manufacture records facing supply problems response created factory capable pumping tons day excess destined production united_states remained officially neutral april increasingly throwing support allies trade counter german ambassador von interior ministry official albert tasked american industry maintaining public support germany agents employee hugo set contract company called chemical exchange association buy excess german owned von american subsidiary supplier acid manufacture july plants selling tons day acid production soon line turn plant running plot lasted months july albert containing details plot recovered secret service agent activities illegal united_states officially neutral trading germany documents soon leaked new_york world anti german newspaper world published august public pressure soon forced end deal embarrassed subsequently sending excess military time deal million dollars plant running reputation took large hit company preparing launch advertising campaign secure connection brand loses foreign holdings beginning set number shell corporations united_states possibility losing control american assets enter war allow enter markets army uniforms declared war germany april alien property mitchell began investigating german owned businesses soon turned attention avoid having surrender profits assets government management shifted stock new company nominally owned americans controlled german american leaders soon uncovered scheme seized american holdings trading enemy act amended allow sale holdings government auctioned plant american patents including brand cross logo bought patent medicine company sterling products inc rights rights sold billion interwar years coming deadly spanish flu secured reputation powerful effective drugs time fever reducing properties gave sick patients strength fight infection companies large small earned loyalty doctors public manufacture purchase meet demand despite people believed germans spanish flu bug causing war tactic patent expired sterling owned trademark commonly term drug united drug company challenged trademark officially generic public sale remained sold demand growing rapidly wake spanish flu soon hundreds brands sale united_states sterling products equipped intellectual property tried advantage new brand quickly possible generic took german expertise run plant finite supply facing competition companies sterling president william ambitions sell compete german abroad taking advantage losses german company suffered provisions treaty versailles worked deal share profits americas australia south_africa great_britain drugs return technical assistance manufacturing drugs sterling took canadian assets ownership trademark valid canada world bought sterling restoring ownership cross trademark canada ownership trademark canada market world war world war new brands based products entered market australian company nicholas limited aggressive marketing strategies george davies built global brand particular strength australia new_zealand american brands burton joseph tried compete american new products mix new uses german companies brands latin_america managed sterling products competed expensive competition new drugs world war dismantled central role nazi regime sterling products bought half ltd british subsidiary half owned small fraction british market competition drug brands ltd began searching new pain compete effectively moderately successful compound drugs mainly utilized ltd manager ordered investigation substance scientists yale found active derivative clinical trials ltd brought market sterling products market united_states countries dominated market firms began selling drugs significantly laboratories liquid pills available cause rapidly displaced sales anti drug introduced sold 1970s relatively small portion pain market 1980s sales decreased available early 1980s studies suggested link children consumption syndrome potentially fatal disease food drug administration required warning labels suppressing sales makers filed lawsuit maker american home products claiming failure add warning labels held sales suit eventually dismissed investigating works mechanism anti properties unknown drug mid twentieth century explanation widely accepted drug brought market relieved pain acting central nervous system harry london laboratory company davis began investigating relationship effects tests guinea pigs found given effects found cutting guinea pigs nerve affect action effect evidence worked locally combat pain central nervous system began working university london graduate student determine precise mechanism effects difficult pin precise live research animals tests removed animal tissues behave like tests years collaboration arranged work john royal college england order learn new methods like possible solution testing failures tested cascade associated shock extracts guinea pig lungs applied tissue rabbit found release unidentified chemical generated guinea pig lungs chemical caused rabbit tissue contract identified chemical called rabbit contracting substance june paper journal nature suggested similar drugs non anti drugs worked blocking production later research showed worked responsible converting acid revival heart drug effects blood agent noticed lawrence family doctor california directing patients laced found unusual number patients hospitalized severe bleeding patients high amounts began recommending daily patients claimed patients followed people signs studies taken seriously medical community controlled study published obscure journals idea prevent diseases heart attacks strokes revived 1960s medical researcher harvey found anti effect blood unlike potential drugs low medical research council john brien picked finding began working peter anti drug potential began large scale trial drug heart attacks nicholas laboratories agreed provide enlisted heart attack survivors double blind controlled study heart attack survivors likely suffer second attack greatly reducing number patients necessary reliably detect effect heart attacks study began february researchers soon break double study american suggested prevented heart attacks deadly found fewer admitted hospital heart attacks non possible explanation caused heart attack die reaching hospital initial results ruled explanation trial ended showed modest significant reduction heart attacks group taking subsequent studies effectiveness heart drug ground evidence mid-1980s relatively new technique analysis richard convinced medical community studies aggregate showed effectiveness relative certainty end 1980s widely drug heart attacks regained position selling


tobacco smoke tobacco smoke tobacco smoke medical treatment employed european physicians range tobacco recognised medicine soon imported new world tobacco smoke western medical practitioners tool cold applying technique adapted north american indians procedure treat gut pain attempts victims near drowning liquid tobacco given ease symptoms early 19th century practice fell decline discovered principal active agent tobacco smoke poisonous tobacco medicine discovery new world tobacco unknown western medicine europeans ignorant effects smoke antiquity effects burning seed known ancient greek physician recommended smoke female diseases elder cure native americans western explorers learnt tobacco leaf variety purposes including religious worship europeans soon aware americans tobacco medicinal purposes french diplomat jean tobacco advocated tobacco treatment long list diseases cancer respiratory problems stomach worms female diseases contemporaneous medical science placed weight short period tobacco use mentioned tool cold brought particular medical effectiveness explained ability moisture warm parts body maintain important healthy person attempt discourage disease tobacco buildings introduction tobacco smoke tube practiced north american indians early example use procedure described thomas cure passion prescribed bleeding followed tobacco smoke conceive proper bleed arm hour throw strong know strong smoke tobacco forced large inverted pipe repeated short interval giving open passage downwards tobacco smoke reportedly 19th century danish farmers horses needed frank reported contemporary native americans treated horses technique medical opinion physicians time appropriate treatment apparent death warmth anne woman sentenced death hanged supposed murder child found alive revived pouring hot throat limbs bleeding applying heating heating cast body heat warmth placing warm bed woman warm recovered fully pardoned artificial blowing smoke lungs thought useful smoke considered potent method supposed warming properties dutch experimented methods lungs treatment fallen canals apparently drowned patients given tobacco smoke respiratory richard western scholars recommend tobacco smoke victims drowning recommended tobacco treat drowning caused therapy cited earliest documented cases applied tobacco smoke seemingly drowned woman treated advice passing sailor woman husband inserted stem sailor pipe covered bowl piece paper blew hard woman apparently revived royal humane society installed kits including smoke points river_thames turn 19th century tobacco smoke established practice western medicine considered humane societies important artificial tobacco breath bleed warm till succeed spare pains day use applied tobacco smoke established way treat canal doctors began experimenting delivery mechanisms experiment half tobacco water patient suffering general expected recovery worked powerful agent penetrate sensibility patient end resulted excited sickness treat middle aged man reported died following application performed treat similar case woman given liquid tobacco supplemented chicken pills taken woman later recovered medical writer noted powers tobacco remarkable arrested attention practitioners remarkable manner effects method exhibiting smoke tobacco written providing list european publications subject smoke treat report medical journal tells woman treated repeated smoke little apparent success according report tobacco successfully treat cholera stage collapse observe called case decidedly set object ordering tobacco smoke favour reduction obscure muscular exist directed girl taken crude mercury frequently raise bed raise alter position belly vice versa view favouring mercury lower decline attacks theories surrounding ability tobacco cure diseases begun early 17th century king james scathing effectiveness writing cure diseases claimed smoking dried brain old people smoke naturally dried certain beliefs effectiveness tobacco smoke protect disease persisted 20th century use smoke western medicine declined animal experimentation benjamin demonstrated principal active agent tobacco smoke cardiac poison stop circulation blood


microscopic skin matter called skin hair mammals humans occur greatest number face parts skin hands feet type referred called type special type tears spots found usually lips inner surround female known found sexes mice rats related medical conditions involve including usually produce excess structure location found areas skin hands feet types connected hair units exist independently found hair covered areas connected hair surround hair surrounded muscles structure like multiple branch central deposit hairs bring skin surface hair shaft structure consisting hair hair muscles known unit found areas skin nose inner membrane cheek unique names lip cheek known spots known breast known montgomery development visible 13th 16th week development hair develop tissue gives rise skin signalling factors increase likelihood presence human substance called translucent white substance coating skin birth activity decreases activity ages years increases peak activity heightened levels function substance called latin fat wax fat producing cells skin hair mammals conjunction play important role hot conditions sweat produced produces sheet sweat readily lost drops sweat importance delaying colder conditions nature coating hair skin rain effectively repelled produced process cells release cell remnants cells constantly replaced base humans primarily composed wax free composition varies species wax unique produced final products body acid acid unique humans implicated development breakdown bacteria produce strong sex known affect rate shown stimulate shown acts primary hair immune function nutrition body system serve protect body form acid mantle fine slightly acidic film surface skin acts barrier bacteria potential penetrate skin skin helps primarily nature important contribution maintaining integrity skin barrier express pro anti properties act delivery system contained broad activity additionally provides upper layers facial skin unique months development produce white substance coats skin protect fluid surrounds female breast fluid volatile compounds thought serve newborn pregnancy called montgomery enlarged form called eye tears serves create seal eyes closed quality prevents sticking known attach directly arranged vertically plates spots found oral yellowish white partly composed produced ear canal high content provides good clinical significance involved skin problems skin pores create plug called common problem particularly teenagers thought relate increased production factors increased production lead cause commonly called lead infection particularly bacteria change characteristic generally occur areas particularly face shoulders upper chest black white depending entire unit blocked build ups mistaken treatments available reducing diet include treatments reduce produced usual treatments fail presence looked possible cause conditions involve include refers cause skin hair referring excessive cells visible small skin particularly forehead nose chronic usually mild form effected changes newborn occur cradle cap like known skin condition characterized overlapping slow growing rare cases precursor cancer syndrome known syndrome uncommon aggressive term refer contain originate true true relatively rare known condition characterized history word meaning consisting termed comes latin documented jean defined separate fat describes oral cavity head ears universally acknowledged viii describes blocked small animals attributes presence oral cavity noting naturally humour puts colours natural state mild intended wet mouth principles physiology noted present hands feet animals mice rats large modified produce territorial marking scent flanks similar composition human responsive basis study disease affects mainly known occur dogs particularly thought generally inherited described cats report describes condition rabbit animals causes hair loss nature distribution hair loss differs greatly additional images


located base human skull bone situated anterior spine bone lateral middle middle vein branch nerve pass landmark close relations described 18th century structure bone situated middle greater wing bone situated directly anterior spine falls posterior lateral posterior tube variation varies size location rarely absent usually case middle enters cavity incomplete occur half population conversely minority cases particularly middle pass bone apex process surface development newborn long adults width extends adults average diameter adults earliest perfect ring shaped formation observed eighth month birth latest seven years birth developmental study majority skull studies round shape derived arch usually attached spine bone found attached rim animals great found bone parts temporal bone found absent function permits passage middle middle vein branch nerve clinical significance distinctive position landmark landmark reveals positions nerve relevant achieving trauma surgery history described danish 18th century named relationship process greater wing bone incorrectly declining literal meaning hole latin correct unused fact additional images


bone middle ear humans mammals involved sound vibrations inner ear shaped small bone oval window smallest named bone human body called resemblance latin structure bone middle ear shaped bone smallest human body rests oval window connected described having base resting oval window head connected anterior posterior limbs latin joint smallest bone human body measures roughly greater head base span development develops second arch sixth eighth week life central cavity presence later animals mammals non legged animals bone usually called reptiles term fish bone called gill arch supporting jaw depending species equivalent term amphibians media variation appears relatively constant size different ethnic groups people central case sound heard affected ear symptoms rarely completely absent function situated inner ear sound vibrations oval window membrane covered opening inner ear stabilized muscle facial nerve clinical relevance spontaneous onset disease characterized abnormal bone inner ear causes adhere oval window ability conduct sound cause hearing loss clinical found people common forms cause noticeable hearing loss likely young age groups females common treatments surgical removal replacement artificial creation small hole base followed artificial hole surgery complicated persistent related damage base bone resulting base history commonly described having discovered professor university naples remains nature controversy description published posthumously commentary spanish credited published description bone named resemblance latin example late latin word probably created times stand latin exist early latin speaking world


insect wing insect wings adult insect enable insects fly found second segments pairs referred respectively insects lack wings strengthened number longitudinal veins cross connections form closed cells membrane extreme examples include patterns resulting fusion cross connection wing veins different evolutionary identification family genus level orders insects physical dynamics flight composed direct indirect flight species employ direct flight wing muscles directly attached wing base small downward movement wing base lifts wing upward insects indirect flight muscles attach wings extensions cause wings wings present sex male groups velvet ants lost workers social insects ants rarely female winged male cases wings produced particular times life cycle dispersal phase mere presence absence wings structure vary migratory phases butterflies rest wings held flat folded number times specific patterns typically folded groups insect wings evolved understood main theories origins insect flight wings developed extensions modifications abdominal gills found aquatic insect wings arose fusion pre existing structures pre existing morphology internal wings consists thin membrane supported system veins membrane formed layers closely veins formed layers remain separate lower cuticle thicker heavily major veins nerve veins connected flow wings veins wing extension contains nerves wing develops dorsal ventral layers closely area forming wing membrane remaining areas form channels future veins nerves occur cuticle surrounding veins heavily provide strength wing types hair occur wings small irregularly scattered larger restricted veins scales highly modified small insects greatly reduced instance radius present conversely increase occur branching existing veins produce veins development additional veins original ones wings large numbers cross veins present insects form wings base respectively given hypothetical scheme wing proposed winged insect based combination speculation fossil data winged insects believed evolved common ancestor represents template modified streamlined natural selection million years according current contained longitudinal veins veins branches named according system devised john george system leading edge wing second longitudinal vein typically radius longitudinal vein branches reach wing margin media fourth longitudinal vein branches reach wing margin fifth longitudinal vein branches reach wing margin anal veins veins leading marginal vein insects small vein called extant insects fused rarely branches leading edge associated base plate vein branch located vein branches separate veins anterior posterior base associated end neck section fourth vein radius branched separate veins radius generally strongest vein wing middle wing undivided branch second branch called radial sector branches radius united anterior end second fifth vein wing media pattern media main branches media anterior divides branches median sector media posterior terminal branches modern insects media anterior lost usual media branched media posterior common basal stem according present interpretations wing branches media retained media primitive anterior branch stem media united radius occurs distinct vein base associated median plate continuously sixth vein wing primarily branched primary takes place near base wing forming principal branches anterior branch break number secondary branches commonly branches second branch mistaken anal main stem associated median plate wing base anal system status independent wing vein recognized wings arises group mature wings insect associated connected wing base closely associated veins base free usually branched veins anal veins immediately associated directly affected movement brings wings number veins vary according expansion area wing usually arise common stem insects veins regarded branches single anal vein veins simple branched veins lobe wing occupied network irregular veins entirely contains distinct small veins vein second vein cross veins run cross veins run adjacent branches radius cross veins run radius media cross veins run media veins wing subject secondary union cross veins orders insects cross veins numerous pattern close network branching veins cross veins definite number cross veins having specific locations constant cross veins cross vein radial cross vein fork cross vein median cross vein cross vein media veins insect wings characterized convex concave placement seen concave convex alternate regularly type branching vein vein opposite position branches concave vein fork concave veins vein convex regular alteration veins preserved veins wing appear fall pattern according tendency fold wing relaxed basal shafts veins convex vein anterior convex branch posterior concave branch regarded convex concave branches primary vein concave branch radius posterior media concave branch media respectively convex concave primitive anterior convex branch posterior concave branch convex concave nature veins evidence determining identities branches veins modern insects demonstrated consistent wings fields wing areas subdivided fold lines wing fold lines wing flight fundamental distinction lines fold lines blurred fold lines permit flexibility vice versa found nearly insect wings line fold line forming variable unsatisfactory boundaries wing complicated transverse folding occurs hind wings insects anal area folded like fan different fields found insect wings anal area area area veins occur anterior area responsible flight powered muscles posterior portion called posterior fields anal fold usual position anterior group anal veins contains radial veins wing flexible basal connection radius second base field folded region median plates wing base bordered fold typically occurs vein usually position fold wing lies immediately fold posterior crosses base vein fold lies immediately vein small variations actual position fold affect unity action veins controlled wing hind wings secondary forms rib fold usually triangular shape veins typically spread like ribs fan veins branched secondary veins alternate primary veins region usually best developed hind wing enlarged form sustaining surface great expansions hind wings clearly regions veins supported wing bases fan areas regions wings true wing represented small membrane vein highly developed higher insects narrow wings reduced fold lost cases wing bend line vein region region wing usually small area base strengthened small irregular developed distinct section wing contain veins area developed free lobe projects beneath angle hind wing serves wings group bears long finger like lobe region termed new wing evidently secondary recently developed wing region region containing general form triangle base triangle wing body apex end longer anterior apex point anterior triangle marks radial vein second line fold wing base field posterior angle wing base pair known developed house fly outer arises wing base evidently represents lobe insects larger inner arises posterior margin wing bearing segment forms protective canopy wing outer turned upside inner affected movement wing deep anal area wing membrane single vein sets lobe outer joints movements wings especially insects wings horizontally rest demand complicated structure wing base mere wing body wing attached body basal area membrane contains number small collectively known include anterior plate base vein group associated radial veins definite median plates base area specifically developed wing insects constitute mechanism wing operated muscle arising characteristic wing base small lobe anterior margin area plate insects developed large flat scale like overlapping base wing membrane forms ample lobe wing body margin generally giving appearance called cord continuous posterior marginal fold plate bearing wing wing base wing insects relations body wing veins shown follows plates second fourth median plates plate usually small anterior margin wing base articulated base vein plate greatly enlarged muscles arising inserted plates edge inserted plate anterior plate wing base anterior supported anterior wing process posterior margin anterior end generally produced slender arm apex associated base vein united body second second variable form mechanical relations definite outer margin body radial vein attached anterior end second presents dorsal ventral wing base ventral surface rests wing process second pivotal wing base specifically radial vein lies posterior region wing form highly variable irregular inserted muscle wing posterior end second posterior wing process small fourth present prolonged process associated bases group veins anal region wing termed veins usually posterior plate wing base active mechanism directly veins muscle revolves lifts arm movement produces wing fourth constant element wing base present usually small plate intervening posterior wing process probably detached piece median plates definitely differentiated specific plates principal important elements apparatus lie median area wing base second separated oblique line forms prominent convex fold wing plate usually attached arm regarded plate constantly present distinct represented general base field wing veins region distinct bases associated outer median plate muscles muscles control flight insects total body mass muscles control flight vary types flight found insects indirect direct insects use indirect muscles attach instead wings suggests muscles contract box distorted transferring energy wing muscles span parallel attached extend direct muscle connection directly wall individual located base wing muscles highly elastic material forms connecting flight muscles wing apparatus derived orders insects flies wasp indirect muscles occupy greatest volume function primary source power muscles causes severe wing muscles causes opposite motion primitive insects beetles use direct muscles responsible developing needed power strokes insect wing muscle strictly tissue unit protein fuel oxygen rates taking place concentrated highly organized tissue steady state rates unit volume represent absolute record biology fuel oxygen rich blood carried muscles occurring large amounts order maintain high level energy flight wing muscles large large length width giant dimensions instance active cross section long wide transport fuel oxygen surroundings sites consumption reverse transport carbon dioxide represent challenge biologist relation transport liquid phase intricate system air tubes system folding features insect species fore hind wing coupled improves aerodynamic efficiency flight common mechanism row small hooks forward margin hind wing lock fore wing keeping held insect species lobe fore wing covers portion hind wing margins fore hind wing overlap broadly hook retaining structure rest wings held insects involve longitudinal folding wing membrane transverse folding folding occur lines fold lines transverse hind wings beetles normally radial base wing allowing adjacent sections wing folded fold line fold situated anal vein fold vein present anal area large folded anterior wing fold little posterior addition anal area folded like fan veins anal veins convex veins concave fold probably different species fold varies position different taxa folding produced muscle arising inserted way contracts points posterior process second result arm upwards finally position completely reversed anal veins articulated way moves carried insect activity muscle flight affects power output wing important flight control insects cuticle causes area wing fold veins consequently energy expended region wings moved flight position general wing extension probably results muscles attached insects flight groups relatively large insects flight muscles attached directly wings wings beat faster rate nerves send command muscles beat living winged insects fly different mechanism involving indirect flight muscles cause wings beat faster rate muscles receive nerve mechanism evolved defining feature basic aerodynamic models insect flight insects use method creates leading edge vortex small insects use mechanism wings insect body apart open air gets creates vortex wing bound vortex moves wing acts starting vortex wing circulation lift increased price wear tear wings insects beating wings rapidly requiring sideways lift insects use flight use thrust found species ants known ants evolution period million years ago major land masses insects began flying insect wings developed understood largely appropriate fossils period development lower main theories origins insect flight wings developed extensions modifications abdominal gills found aquatic developed fossils fossils million years ago million years ago different genera insects fully functional wings little preservation transitional forms periods earliest winged insects time period including primitive stem group early large distinct cup vein wing vein lying near fold reaching wing posterior margin oldest definitive insect fossil estimated million years old possessed feature associated winged insects dominant aerial predator probably dominated terrestrial insect predation true appeared prototypes oldest winged fossils different wings way prototypes beginnings modern attributes late possible captured small species wing span earliest beetle like species pointed leather like cells pits true bugs appeared form having unusual possibly single large wing species instead usual found australia family despite numerous features included account loss convex reaching wing margin formation anal loop hypothesis hypothesis suggests insect wings developed found insect fossils believed assisted falling favor hypothesis tendency insects climbing branches escape dropping ground served enable insect land theory suggests gradually grew larger later stage developed joint later appear muscles crude wings model implies progressive increase effectiveness wings starting finally active flight lack substantial fossil evidence development wing joints muscles poses major difficulty theory seemingly spontaneous development largely rejected experts field hypothesis theory suggested possible origin insect wings abdominal gills found aquatic insects according theory gills started way exits respiratory system time modified locomotive purposes eventually developed wings gills equipped little tiny straight muscles hypothesis hypothesis strongest evidence stems adaptation respective inner outer aspects primitive limb advanced based study pod variation displayed transforming normal wings interpreted triple leg arrangement additional lacking wing surface normally strong evidence dorsal fusion leg fitting better hypothesis required evolution wings present plus leg gene recruitment hypothesis fossil larvae provided important new clues disputed question evolutionary origin insect wings larvae fossil discovery hypothesis leg hypothesis considered incompatible alternative explanations supported set fossil record comparative morphology developmental biology expression leg genes insect wing universally considered conclusive evidence favour leg hypothesis proposes insect wings derived mobile leg larvae abdominal gills ancestors generally considered corresponding structures insect wings articulated dorsal plates seen modern larvae abdominal fused rings traces left development gills wings corresponding serial structures share evolutionary origin new results demonstrate wings origin proposed classical hypothesis suggested new hypothesis reconcile apparently conflicting evidence developmental wings originated stiff plates later evolution mobile articulated secondary recruiting leg genes suggestions wings evolved initially sailing surface water seen alternative idea drives directed aerial descent phenomena found sister taxa winged insects earliest similar sets wings direct flight muscles ability fold wings insects today evolved simplified pair wings pairs functioning single pair system indirect flight muscles natural selection played enormous role wings control sensory systems affects noteworthy trait wing twist insect wings twisted helicopter blades higher angle attack base twist generally degrees addition twist wing surfaces necessarily flat larger insects wing membranes distorted angled veins way cross section wings wing basic shape capable generating small lift zero angle attack insect wing insects control wings adjusting tilt frequency wings tiny muscles insects evolved wing features flight play role mating protection insects occupying biological need incredibly find food tight spaces capable escaping larger predators predators need capture prey aerodynamic viewpoint provided high lift thrust forces typical insect attain lift forces times weight horizontal thrust forces times weight substantially different insect flight mechanisms advantages primitive flight mechanism mean able certain ways evolved afterward development wings insects clearly defined members undergo complete species wing develops stage insects life cycle insects undergo incomplete stage different wing insects wings start found underneath exposed indication wing observed insect species early embryo earliest stages life cycle development morphological features embryo cluster cells grow underneath later development lateral grown form wind disc example wing development larvae seen white butterflies second prominent form pocket like structure fourth elongated greatly extended protruding wing close fifth wing pushed wing pocket continues lie old cuticle stage butterfly stage wing exposed shortly wing begins expand form definitive shape development wings begin wing form important note develop near large fourth cells greatly enlarged extend cavity wing cell having developed closely origin position origin position development single cell subsequent opening communication stretching reach parts wing earlier stages development wing provided special organs resembles respect portions noted developed near large cross section shown represents sections parts second fourth respectively time extend forming vein wing marks beginning stadium stage functional time function having replaced wing nomenclature nomenclature insect orders based ancient greek word wing adaptations variation insect wings fundamental identifying classifying species set structures studying insects significant order insect family distinctive wing shapes features cases species distinguished differences color pattern example position identify species albeit lesser extent insects fold wings rest rest wings spread horizontally groups hold wings sloped roof like backs wrap wings bodies flies butterflies close wings straight upward times shape wings type insect flight best flying insects tend long slender wings species large sharply pointed forming small hind wings triangle suggestive wings fast modern possibly important size power muscles speed power flight flying insects wings adapted stresses flight veins thicker stronger closer edge leading edge thinner flexible rear edge trailing edge makes insect wing constructed capable propulsion lift drag variation wing beat occur different species individuals different times general frequency dependent ratio power wing muscles resistance load large winged light bodied butterflies wing beat frequency second small winged heavy bodied flies bees beat wings times second beat times second goes flight generally difficult estimate speed insects flight insects probably fly faster nature controlled experiments species beetles functional wings hind wings hind wings longer folded wing rotated forwards base flight position action spread wing spring mechanism wing structure help abdomen movement wing folded position beetle wing reduced modified folding structure include posterior leading wing marginal fused length radius anterior divided branches middle wing radius posterior basal connection lost media posterior branches long strong vein anterior anal veins veins separated anal fold species beetles pair wings modified hardened form protect delicate folded beneath connected called wings connected meaning wing greek flight tend cover hind body protect second pair wings raised order hind flight wings beetle flight wings crossed veins folded landing veins stored beetles ability fly lost include ground beetles family true family desert cave dwelling species families species fused forming solid shield abdomen families ability fly lost best known example glow worms family females lives pairs wings found middle segment respectively recent genera wings second segment pronounced primitive forms similarly sized wings segments wings covered scales arranged like forming extraordinary variety seen color evolved powerful muscles propel butterfly air wing said segment having stronger vein structure largest wings modified act hearing organs modifications wing include found butterflies radius leading wing marginal fused close length hind wing fused developed area branches butterfly radius radius divides branches middle wing branches butterflies separated radius sector hind wing media basal section lost anterior cup section lost anal veins vein veins vein hind wing butterflies vein area hind wing overlapped fore wing vein strengthened hind wing overlapped area wings better wings head parts abdomen covered minute scales feature order derives names word ancient greek meaning scale scales blade like attached forms hair like specialized secondary sexual characteristics surface complex structure gives color colors contained dimensional structure scales provide number functions include aiding flight important large diversity vivid indistinct patterns provide help organism protect camouflage seek mates species pairs wings equal size shape clear color counted main vein stems wings wing veins fused bases wings folded body rest include leading edge wing strong marginal extends apex wing second longitudinal vein joins radius media fourth longitudinal vein strongest vein wing branches reach wing margin media anterior reach wing margin veins respectively fifth longitudinal vein posterior cup reach wing margin anal veins veins formed second main vein meets leading edge wing black carried near wing tip main veins form wing pattern patterns different different species numerous australian wings veins patterns pattern useful species identification settle wings held sideways slightly downward settle wings held dorsal surfaces oblique held way wings fit abdomen appear held straight butterflies families wings held horizontally rest genus wings held typical resting position adult species possess pairs equal wings appear main vein stems formed second main vein meets leading edge wing families conspicuous carried near wing tip identification based likely confusion order wings early years 20th century regarded related given resemblance orders entirely superficial broader wings divides cell triangle species tough narrow normally covering hind wings abdomen rest hind wings board folded fan like manner include following leading marginal hind wing second longitudinal vein radius longitudinal vein branched hind wing media anterior fourth longitudinal vein branched basal media posterior fifth longitudinal vein hind wing dividing near wing base branched cup anal veins veins hind wing leading marginal hind wing absent second longitudinal vein radius longitudinal vein branched hind wing media anterior fourth longitudinal vein branched basal media posterior fifth longitudinal vein anal veins veins hind wing group rest group stick insect tough short covering base hind wings rest hind wings tough like large anal area folded fan like manner branching stick insect wing veins orders praying rigid aren flying called true bugs hardened lesser extent beetles example anterior wings bugs hardened posterior called found wings typically entirely species glass like good fly seconds flying hind wing hooked hind wing margin species basic shown following picture leading wing marginal extends lies close radius fused radial sector arises near radius anterior radius posterior media branches anterior branches posterior cup anal veins veins fused cup folded notice ambient veins peripheral membranes margin wings true flies pair functional wings posterior pair wings reduced help fly sense orientation movement improve balance acting similar portion wings modified somewhat flaps called cover found leading wing vein radius branched media branched anterior cup reduced species separated species meets reaching wing margin species fused anal veins anal veins present distinctive species cell defined species species known flight form protection hind wings veins hind wing wing large anal lobe folded rest cup anal lobe usually folded fan like manner leading edge wing second longitudinal vein relatively short radius longitudinal vein branches media fourth longitudinal vein reach wing margin anterior fifth longitudinal vein branches occupy large posterior cup curved reach wing margin anal veins veins adults include bees non working ants pairs wings found radius branched media fused length cup absent anal veins anal veins present distinctive species wing row hooks leading edge hind wing engage hind margin strongly couple wings flight line wing folding species including folded line wing folding rest present species forward margin hind wing bears number hooked lock fore wing keeping held smaller species largest considerable number keeping wings especially tightly wings relatively veins compared insects especially smaller species families relatively poor readily blown wind speeds wings soon landing acceptable site mate attempt form nest damp timber earth wings heavy veins basal edge near wing tip angled making cells subterranean wings major veins edge cross veins perpendicular veins making square rectangular cells species slender hind wings long fringes hair called fringed wings species wings hind wings clothed


nerve nerve main nerve carries sensation external sexes skin motor supply pelvic muscles including male female external external anal damaged commonly cause sensory loss nerve temporarily blocked procedure canal known eponymous term canal benjamin irish documented canal structure nerve paired meaning nerves left right body formed roots immediately converge upper border muscle roots middle lower root join form lower cord turn unite form nerve proper roots derived ventral second fourth spinal nerves primary contribution coming fourth nerve passes muscle muscles leaves lower greater crosses lateral lesser accompanies internal internal vein upwards forwards lateral wall contained termed canal internal blood vessels inside canal nerve divides branches giving inferior nerve nerve continuing dorsal nerve males dorsal nerve females nucleus nerve major branch fibers originating nucleus region spinal cord variation nerve vary origins example nerve actually originate nerve consequently damage nerve affect nerve dorsal nerve contribute fibers nerve rarely function nerve motor sensory functions carry fibers carry sympathetic fibers nerve supplies sensation males females branches dorsal nerve dorsal nerve posterior males females supplied posterior nerves males posterior nerves females nerve nerves supplying sensation areas branches supply sensation anal canal providing sensation nerve responsible component erection erection responsible branches muscles pelvic floor muscles muscle including females males external anal inferior anal branch male female external functions external responsible tone release means periods increased release skeletal muscle external contracts causing retention periods decreased release skeletal muscle external allowing occur unlike internal muscle external skeletal muscle voluntary control nervous system clinical significance nerve block known saddle nerve block local technique procedure labor procedure agent injected inner wall nerve damage nerve compressed stretched resulting temporary permanent nerve injury occur nerves stretched normal length pelvic floor stretched prolonged difficult chronic caused nerve vulnerable stretch induced nerve known canal syndrome rare associated professional cycling diseases diabetes multiple damage nerve mechanisms pelvic notably large surgery remove cause permanent damage nerve causes crossover external anal occurs individuals imaging nerve difficult routine imaging guidance needle placed adjacent bundle spine easily identifiable structure level injection spinal needle advanced muscles advanced millimeters spine contrast ray injected highlighting nerve canal allowing confirmation correct needle placement nerve injected local confirm treat chronic pain external known females pelvic pain nerve testing time taken muscle supplied nerve contract response electrical applied sensory motor fibers increased time terminal motor signifies damage nerve measuring mounted finger mark history term comes latin meaning external derived meaning parts ashamed canal known eponymous term canal benjamin irish documented canal documented existence canal nerve contribution robert anatomy physiology additional images


latin neck lower human female reproductive system non pregnant woman usually long inch roughly cylindrical shape narrow central canal runs entire length connecting cavity opening called internal opening called external lower known portion documented time years ago canal passage sperm travel egg cell sexual intercourse methods including caps aim block prevent passage sperm canal methods fertility awareness model method changes consistency period allow progress birth canal doctors use extent assist decision making canal lined single layer column shaped cells covered multiple layers cells topped flat cells types meet junction infection human cause changes lead cancer tests detect cancer enable early successful treatment ways avoid include avoiding sex developed early 21st century reduce risk cancer preventing main cancer causing strains structure female reproductive system centimetres length lower narrower continuous broader upper body lower end anterior wall referred portion rest called portion central canal known canal runs length connects cavity body openings known internal external external respectively lining canal known covering known inner layer thick layer smooth muscle portion covering consisting tissue upper lies separated cellular tissue known extends sides rear covered runs wall turns upwards forming tightly connected surrounding structures rest canal varies greatly length width women course woman life measure inch widest diameter adults wider middle narrower end anterior posterior walls canal vertical fold ridges run upwards known resemblance palm leaf anterior posterior ridges arranged way close canal pregnancy known portion convex elliptical shape projects anterior posterior rounded small depressed external opening connecting size shape external opening external vary according age state natural normal taken place women delivery external opening small circular women delivery like average long wide blood supplied descending branch drains vein pelvic nerves emerging transmit sensation pain brain nerves travel pass anterior channels facilitate drainage anterior lateral drains travelling cardinal base broad external ultimately posterior lateral drains internal ultimately posterior section drains variations drainage travels different sets pelvic people implications scanning involvement cancer directly influence undergoes series changes position texture cycle remains firm positioned low closed approaches softer rises open response higher levels present changes accompanied changes described development component female reproductive system derived called develop sixth week development outer parts fuse forming single canal grows size smaller rate body relative size time decreases decreasing larger body life twice large childhood decreasing adult size smaller previously thought development original derived original derived point original meet called original junction new studies large derived tissue differences causes millimetres thick lined single layer cells contains numerous tubular contrast covered resembles lining junction types called junction underlying types tough layer shed tissue including rest girls functional junction present canal entering influence pregnancy extends causes junction portion exposed acidic environment exposed undergo change tougher days weeks mature similar original new junction internal original junction zone unstable junctions called transformation zone structures functional junction moves canal form transformation zone lining replaced caused outlet build forms usually diameter considered openings helpful identify transformation zone function fertility canal sperm enter sexual intercourse forms artificial sperm remains act reservoir releasing sperm hours chances theory states draw theory generally accepted years disputed lack evidence small sample size errors methods fertility awareness model method involve estimating woman periods fertility observing changes body changes involving quality sensation causes transparency presence produce day increasing time contains large proteins known water content varies cycle composed water reaching changes allow function barrier transport medium contains calcium potassium organic components proteins trace elements including copper iron free consistency determined influence time period high levels thin allow sperm enter sperm higher results pattern observed drying low resembling leaves character described prominent time times cycle thick acidic effects acts barrier sperm entering women taking oral thick effects thick prevents interfering nascent pregnancy plug called forms inside canal pregnancy provides protective seal entry plug known properties plug released stage shortly visible blood tinged discharge plays major role descends preparation birth presenting usually head rests supported labour progresses softer shorter begins face support provides head starts way begins diameter accommodate head descends wider shorter phenomenon known factors doctors use extent assist decision making generally active stage labour strong regular begins second phase labor begins regarded active pushing push baby birth canal leading birth baby number past deliveries strong factor influencing rapidly able labour time taken factor reporting systems bishop score recommend delivery induction section incompetence condition shortening occurs term pregnancy short length strongest birth methods involve firm plastic devices inserted woman prior intercourse cover pressure walls maintain position acts physical barrier prevent entry sperm preventing caps similar method smaller adhere caps conjunction year women undergo pregnancy optimal use falls rates lower cap women undergoing pregnancy optimal use types pills effective making difficult sperm pass canal addition prevent contrast pills contain combined oral pills work mainly preventing thin lining enhancing effectiveness clinical significance cancer cancer common cancer women worldwide rates varying geographically cases women leading cause cancer related death poor countries delayed diagnosis leading poor outcomes common introduction routine screening resulted fewer cases deaths cancer mainly taken place developed countries developing countries limited screening global burden occurring cancer nearly involves human infection virus numerous strains changes particularly transformation zone common area cancer start reduce cancer viral strains involved cancer development potentially changes detected screening methods including called cells surface examined microscope instrument view invented developed procedure heated loop platinum patch tissue developed parts developed world including test superseded liquid based cheap cost effective practical alternative poorer countries visual inspection acid sustaining based programs regions difficult need trained personnel equipment facilities difficulties follow results treatment available day screening test comparable accurately identifying result usually investigated taking cone remove possible result represents changes eventually progress invasive cancer cases cancer detected way having caused symptoms symptoms occur include bleeding discharge discomfort referred associated associated discharge sexually transmitted half pregnant women having infection causes include flora associated caused virus investigated directly appear taking examining bacteria special tests identify particular bacteria given treatment refers narrow canal typically associated trauma caused removal tissue investigation treatment cancer cancer prevent labour strongly associated development daughters exposed women include clear cell ridges development appearance rare condition completely fails develop associated concurrent failure develop exist associated situations tissue present cause bleeding present canal refers horizontal lining cell thick layer mammals female paired species single single share morphological characteristics grouped clade family unusual lack defined thought lost characteristic mammals developing lineage etymology pronunciation word came english latin means neck like counterpart refer neck body analogous narrowed object neck english word usually refers refer neck cap cancer latin came european root referring structure projects word related english word horn persian word head greek word head greek welsh word deer welsh documented literature time cancer described years ago descriptions provided variation word sense early writers term refer internal attested use word refer


ear ear organ hearing mammals balance mammals ear usually described having parts outer ear middle ear inner ear outer ear consists ear canal outer ear visible portion ear animals word ear refers external middle ear includes cavity inner ear sits bony labyrinth contains structures key senses canals enable balance eye tracking moving enable balance stationary enables hearing ears placed somewhat head arrangement aids sound ear develops small develop early embryo called derived ear affected disease including infection traumatic damage diseases ear lead hearing loss balance disorders conditions affected damage brain pathways leading ear ear adorned jewellery numerous cultures thousands years subjected surgical alterations structure human ear consists parts outer ear middle ear inner ear ear canal outer ear separated air filled cavity middle ear middle ear contains small bones involved transmission sound connected throat opening tube inner ear contains organs canals belonging system system outer ear outer ear external portion ear includes visible called ear canal outer layer called membrane consists curving outer rim called inner curved rim called opens ear canal partially ear canal facing hollow region ear canal called ear canal stretches inch canal surrounded second near surrounded bone bony known formed temporal bone skin surrounding ear canal contains produce protective ear wax ear canal ends external surface sets muscles associated outer ear muscles mammals muscles adjust direction humans muscles little effect ear muscles supplied facial nerve supplies sensation skin ear external ear cavity great nerve nerve nerve lesser greater nerves supply sensation parts outer ear surrounding skin consists single piece elastic complicated relief inner surface fairly smooth configuration posterior surface known darwin present lying descending corresponding ear tip mammals consists tissue symmetrical arrangement ears allows sound brain comparing arrival times ear circuits located superior complex bodies connected pathways ears middle ear middle ear lies outer ear inner ear consists air filled cavity called cavity includes tube round oval windows small bones function receive transmit sound inner ear hammer smallest named bone body middle ear connects upper throat opening tube transmit sound outer ear inner ear receives vibrations sound pressure connected longest handle vibrations turn vibrations small bone wide base rests oval window vibrations transmitted oval window causing movement fluid round window allows fluid inner ear pushes secondary membrane fluid inner ear moves pushes membrane round window corresponding middle ear help sound waves nearly times inner ear inner ear sits temporal bone complex cavity called bony labyrinth central area known contains small fluid filled connect canals canals angled right angles responsible dynamic balance spiral shell shaped organ responsible sense hearing structures create labyrinth bony labyrinth refers bony compartment contains labyrinth contained temporal bone inner ear structurally begins oval window receives vibrations middle ear vibrations transmitted inner ear fluid called fills labyrinth situated eventually spiral shaped structure consists fluid filled spaces hair cells responsible changing mechanical changes electrical present organ blood supply blood supply ear differs according ear outer ear supplied number posterior provides majority blood supply anterior provide supply outer rim ear posterior direct branch external anterior branches superficial temporal plays role middle ear supplied branch posterior deep branch present play smaller role include branches middle ascending internal canal inner ear supplied anterior branch branch posterior branch middle arising anterior inferior function hearing sound waves travel outer ear middle ear transmitted nerve inner ear nerve information temporal lobe brain registered sound sound travels outer ear impacts causes bones transmit sound second window oval window protects fluid filled inner ear detail outer ear helps focus sound impacts rests membrane receives vibration vibration transmitted oval window small muscles help noise muscles contract excessive vibrations vibration oval window causes vibration inner ear houses apparatus necessary change vibrations transmitted outside world middle ear signals passed nerve brain hollow channels inner ear filled liquid contain sensory hair cells microscopic hairs cells structural protein project fluid hair cells release chemical stimulated sound waves moving fluid flows cells organ fluid pushes individual cells movement causes cells open receive potassium rich causes cell creates action potential transmitted spiral sends information portion nerve temporal lobe brain human ear generally hear sounds frequencies audio range sounds outside range considered hearing requires intact functioning portion central nervous system working ear human extreme sound commonly occurs inner ear nerves tracts central system balance providing balance moving stationary central function ear ear types balance static balance allows person feel effects gravity dynamic balance allows person sense acceleration static balance provided cells lining walls contain fine cells covered fine gelatinous layer cell small large gelatinous layer lie tiny formations calcium person moves shift position shift positions opens channels cell membranes creating action potential transmitted brain nerve dynamic balance provided canals canals right angles end canal slight known contains numerous cells central area called fluid canals according momentum head person changes acceleration fluid changes affects pressure results opening channels causes passed signal brain nerve dynamic balance helps maintain eye tracking moving development ear develops distinct structures inner ear middle ear outer ear structure originates different layer inner ear second week developing embryo consists layers ear develop inner ear begins form 22nd day embryo development specifically inner ear derives called head forms pit entire mass eventually surrounded form bony labyrinth 33rd day development begin differentiate closer embryo form canals closer embryo differentiate rudimentary eventually eventually rise connect appears approximately sixth week connects begins differentiate formed media contain fluid called media contains set membranes called membrane membrane develop separate respectively parts turn form nerve form supply sensation parts inner ear sensory parts canals organ nerve begins form 28th day molecular regulation genes responsible regulation inner ear formation members gene family genes development inner ear structures regulated turn controlled master gene middle ear middle ear components develop second arches cavity tube develop arches area develop develops structure called normally appear half development derive arch derives second develop crest eventually cells tissue surrounding experience new layer constitute formation cavity wall outer ear unlike structures inner middle ear develop ear canal originates dorsal portion fully expanded end 18th week development layers tissue originates fusion derived lower arch form respectively final derived upper second arch form outer ears develop lower neck forms final position level eyes clinical significance hearing loss hearing loss partial total result injury damage disease causes hearing loss result injury damage outer ear middle ear known hearing loss result injury damage inner ear nerve brain known hearing loss causes hearing loss include ear canal blocked ear wax fixed absent holes hearing loss result middle ear causing fluid build normally air filled space media general operation repair middle ear muscle rebuild intact artificial ear bones placed substitute damaged ones disrupted chain rebuilt order conduct sound effectively hearing aids hearing loss severe prolonged hearing aids work sound local environment best suited hearing loss transmit sound heard nervous signal bypassing common include ring children present cases abnormal ear canals low ear rare cases formed extremely small small develop develop properly ear canal fail develop properly surgery treat hearing loss considered option children older surgical procedure reduce size change shape ear called initial medical intervention aimed assessing baby hearing condition ear canal middle inner ear depending results tests reconstruction outer ear stages planning possible repairs rest ear approximately thousand children suffer type related development inner ear inner ear related hearing loss generally diagnosed scan magnetic resonance imaging scan hearing loss problems derive inner ear development separate middle external ear middle ear occur errors head neck development syndrome associates middle ear structures non temporal bone ear canal related structure ear known associated hearing loss hearing loss refers inappropriate perception motion system common type displaced canal displaced rests causing sensation movement disease strokes diseases result perception injury outer ear injuries external ear occur fairly frequently leave minor major injuries include injuries burn repeated twisting pulling ear discipline torture chronic damage ears cause ear common condition wrestlers ears distorted owing persistence blood supply healing owing exposed position external ear susceptible skin including cell basal cell middle ear ear drum event large sound explosion diving flying called objects inserted ear common cause injury infection media cause discharge ear called investigated treatment include waiting possibly surgery injury prolonged position affected skull skull containing ear structures temporal bone cause damage middle ear skin cells develop birth secondary causes chronic ear hearing cause usually investigated require scan treatment surgery inner ear principal damage mechanisms inner ear society hair cells exposure elevated sound levels noise trauma second exposure drugs substances large number people exposed sound levels daily basis likely lead significant hearing loss national institute safety health recently published research estimated numbers persons hearing difficulty percentage attributed noise exposure furthermore according national health nutrition examination survey approximately million workers reported exposure hazardous workplace noise workers exposed hazardous noise potential developing noise induced hearing loss wear hearing protection hearing sound external sound present described ringing sound like rarely unclear voices music heard sound soft loud low pitched high pitched appear coming ear time comes gradually people sound causes depression anxiety concentration difficulties disease result number underlying causes common causes noise induced hearing loss causes include ear disease heart blood vessels disease brain emotional stress exposure certain previous head injury common depression society culture ears jewelry thousands years traditionally piercing ancient modern cultures ornaments placed stretch allowing larger slid large gap lobe tearing weight heavy traumatic pull example fairly common injury ears present roman times method punishment roman times dispute arose settled injured party cited person thought responsible appear specified time limit summoned witnesses statements refused happened injured party allowed drag ear pinch hard resisted french expression literal meaning ear pulled meaning lot use expression pull ears mean inflict punishment effect facial appearance western societies protruding ears present ethnic europeans considered particularly surgery reduce projection prominent ears published medical literature case report ears characteristic creatures folklore french brazilian japanese earth spider feature characters art old ancient greece medieval europe ears common characteristic creatures fantasy genre including characteristic creatures horror genre vampires ears found science fiction genre example vulcan races star trek universe character men universe von hungarian born hungary awarded nobel prize physiology medicine research function hearing organ mouse laboratory mouse looked like human ear grown ear actually ear shaped structure grown cow cells ear shaped mold skin mouse naturally grew developed alternative ear repair procedures results met publicity controversy animals helps direct sound ear canal complex geometry ridges inner surface ears helps sharply focus sounds produced prey signals ridges regarded acoustic equivalent lens seen wide range animals including bat lesser bat fox mouse large humans undeveloped ear muscles non functional structures large easily identified ear muscle ear reason lost biological function serves evidence related species humans muscles people able ears directions said possible gain movement repeated trials inability ear compensated mainly ability easily turn head horizontal plane ability common function provided structure replaced animals mobile like horse aimed independently better receive sound animals help direction sound source invertebrates animals ears invertebrates detect sound kinds sense organs insects organs hear distant sounds located head depending insect family organs insects extremely sensitive offering acute hearing animals female cricket fly organs abdomen connected thin bridge function like tiny pair linked provide acute directional information fly uses ears detect host male cricket depending song cricket coming fly hearing organs slightly different frequencies difference little second allow fly home directly singing male cricket simpler structures allow detect near field sounds spiders example hairs legs detecting sound hairs body perceive vibrations allow respond sound


tongue muscular secondary tongue found primary tongue living includes collectively called fully developed similar structures found mammals second tongue lacks taste thought remove hair debris specialized dental structure fur oral rigid structure called runs center support usually underside tongue consists singular run sides end like edges hardened freely limited range found particularly small tongue floor mouth large highly closest living relatives lack thought evolved specialized tissue tongue seen mammals found underside version widely variable appearance tissue term confused tissues structure tongue secondary tongue located primary tongue mammals structure taste relatively large edge usually lined called denticles middle thick strengthening rod called connects underside tongue tongue thickness size vary species provides support tip free small distances underside tongue majority length underside tongue free moving called attach base supported highly developed specialized makes majority fold connects tongue rear floor mouth called structure consisting tiny floor mouth point rear floor mouth marks location differences species shaped like brush like instead area hook shaped structure end lacks gray mouse distinct ends lobe like projections lack ridges rigid tip simpler structure making clearly distinguishable distinct large stick entire underside tongue prominent common developed noticeable specialized conspicuous function originally thought organ inherited ancestors remove hair debris highly specialized arrangement long forward facing teeth lower jaw oral consists teeth reinforce finely spaced teeth act like teeth cleaning function suspected nearly century clear confirmation study presented evidence accumulated mat hair oral author observe extend tongue rapidly possibly use clean replaced evolving continually growing like hook shaped tip fits precisely gap lower keeps area clean lack explain lacks typically found consisting edges tips instead finely spaced elongated teeth instead cleaned tongue edges match evolution development evolved specialized tissue tongue seen sugar mammals dogs found adult mammals close relatives developed suggests phylogenetic relationship fully developed particularly unique closely related collectively called developed non specialized highly specialized found tongue version disputed structure appearance tissue vary greatly result terminology confused species derived bone arch bone supports tongue instead separately developed structure specifically adapted support


human tooth human teeth function breaking items food cutting crushing preparation different types teeth type tooth different job cut food tear food crush food roots teeth embedded upper jaw lower jaw covered teeth multiple tissues varying density teeth distinctive long lasting features species humans like mammals meaning develop sets teeth set called baby milk primary deciduous set normally starts appear months age babies born visible teeth known teeth normal tooth eruption months known painful anatomy dental anatomy field anatomy dedicated study tooth structure development appearance classification teeth fall field study dental contact teeth dental anatomy taxonomic science concerned naming teeth structures information serves practical purpose enabling easily identify teeth structures treatment crown tooth area covered junction neck tooth crown composed british english pulp chamber inside crown bone eruption eruption visible root found covered crown root normally pulp canals tooth multiple roots root single rooted teeth usually root usually roots usually roots additional roots referred roots humans usually primary deciduous baby milk teeth permanent adult teeth teeth classified called primarily biting pieces foods raw uncut primarily grinding foods bite size pieces inside mouth teeth identifiable features distinguish different systems refer specific tooth common systems world dental federation universal numbering system method system worldwide universal widely united_states primary teeth deciduous primary teeth found upper jaw lower jaw total dental formula primary teeth primary set teeth types types second primary teeth normally later replaced permanent counterparts permanent teeth permanent teeth found total dental formula teeth central lateral second second teeth central lateral second second commonly called wisdom teeth mouth form additional teeth form example fourth fifth rare referred teeth development fewer usual number teeth called parts hardest highly substance body major tissues tooth dental pulp normally visible supported underlying consists mineral water organic material comprising rest normal color varies light yellow grayish white edges teeth underlying color slightly blue tone color dental material underneath strongly affects appearance tooth varies thickness surface tooth border seen wear rate called attrition year normal factors primary mineral calcium large minerals accounts strength necessary support unlike bone contain instead unique classes proteins called role proteins fully understood believed aid development serving framework support functions substance pulp chamber dental pulp formation known yellow material materials organic materials water weight softer rapidly subject severe properly treated acts protective layer supports crown tooth tissue organic matrix proteins microscopic channels called outward pulp cavity exterior border diameter range near pulp near junction tiny branches intersect length dictated radius tooth dimensional configuration genetically determined specialized bone like substance covering root tooth approximately material mainly organic material mainly water root tooth root apex coloration yellowish softer principal role serve medium attach tooth stability junction lack cellular components type covers root form cellular covers root apex pulp dental pulp central tooth filled soft tissue tissue contains blood vessels nerves enter tooth hole apex root border pulp initiate formation cells pulp include pulp commonly called nerve tooth development tooth development complex process teeth form cells grow mouth diverse species teeth non human tooth development largely humans human teeth healthy oral environment develop appropriate stages development primary teeth start form sixth eighth weeks permanent teeth begin form twentieth week teeth start develop near times develop significant research focused determining processes initiate tooth development widely accepted factor tissues arch necessary development teeth tooth development commonly divided following stages stage cap bell finally maturation staging tooth development attempt changes place frequently difficult decide stage assigned particular developing tooth determination complicated varying appearance different sections developing tooth appear different stages tooth called tooth cells eventually forms tooth organized parts organ dental dental organ composed outer inner cells rise produce reduced growth loop cells deeper tissues forms root determines tooth root shape dental contains cells develop forming cells additionally junction dental inner determines crown shape tooth dental gives rise important entities form tooth rise bone roots teeth develop connect teeth bone eruption tooth eruption humans process tooth development teeth enter mouth visible current research indicates play important role tooth eruption primary teeth mouth months years age teeth ones mouth person years old time permanent tooth stage person combination primary permanent teeth known mixed stage mixed stage lasts primary tooth lost remaining permanent teeth mouth theories cause tooth eruption theory proposes developing root tooth pushes mouth known theory resulted microscopic study teeth thought root later discovered merely artifact created process preparing slide currently widely held belief provide main impetus process onset primary tooth loss found strongly psychological criteria school readiness supporting structures supporting structure tooth helping attach tooth surrounding tissues allow touch pressure consists bone tooth connect bone bone surrounds roots teeth provide support creates commonly called lying bone readily visible mouth specialized tissue tooth bone tissue covers root tooth bone width size decreases time functions include attachment tooth bone support tooth formation bone tooth movement sensation eruption cells include cell rests consisting type iii fibers grouped named according location groups fibers named crest horizontal oblique fibers nerve supply generally enters bone tooth forms network tooth crest pressure exerted tooth biting tooth moves slightly puts tension nerve fibers send information central nervous system interpretation bone bone bone jaw forms teeth like bone human body bone modified life create bone destroy especially force placed tooth case movement teeth attempted area bone force tooth moving high level resulting bone area bone receiving tension attached tooth moving away high number resulting bone formation tissue jaws different types associated types form mass cells known tooth mouth associated directly tooth attachment visible mouth composed basal forms attachment tooth tissue touches attached tooth tooth decay plaque plaque consisting large quantities bacteria form teeth removed regularly plaque buildup lead problems given time plaque forming form entirely bacteria mainly composition varying location mouth important associated dental certain bacteria mouth live remains foods especially absence oxygen produce acid calcium process known leads tooth destruction gradually cause tooth surface rise critical causes return dissolved minerals sufficient time intake foods impact limited teeth repair unable penetrate plaque acid produced bacteria dental described tooth decay infectious disease damages structures teeth disease lead pain tooth loss infection dental long history evidence showing disease present bronze iron middle ages prior period largest increases prevalence associated diet changes today remains common diseases world united_states dental common chronic childhood disease times common countries experienced overall decrease cases tooth decay continue distribution disease children united_states europe cases dental occur population tooth decay caused certain types acid producing bacteria cause damage presence resulting acidic levels mouth affect teeth tooth special mineral content causes sensitive low depending extent tooth destruction treatments restore teeth proper form function aesthetics known method large amounts tooth structure instead dental health organizations advocate measures regular oral modifications avoid dental tooth care oral practice keeping mouth clean means preventing dental disease bad breath dental disorders consists professional personal care regular usually dental remove plaque develop careful professional cleaning includes tooth scaling instruments devices remove deposits teeth purpose cleaning teeth remove plaque consists bacteria healthcare professionals recommend regular twice day morning evening meals order prevent formation plaque able remove plaque areas teeth result considered necessity maintain oral correctly dental removes plaque teeth line disease begins develop electric popular aid oral user disabilities proper training manual good motivation achieve standards oral satisfactory best electric users rarely achieve kind electric equally effective good design needs properly best effect electric tend help people good cleaning teeth result oral problems important advantage electric ability aid people difficulties associated therapy recommended protect dental water decrease dental helps prevent dental decay binding crystals incorporated makes resistant resistant decay recommended protect teeth surfaces include application solutions routine tooth damaged destroyed restoration missing structure achieved variety treatments created variety materials including glass gold composite small placed inside tooth referred formed directly mouth cast lost wax technique larger portions tooth lost restoration fabricated artificial crown restore involved tooth tooth lost bridges replacements usually costly usually expensive replace complete arches mouth partial number teeth bridges replace smaller spaces missing teeth use adjacent teeth support restoration dental replace single tooth series teeth expensive treatment option desirable restoration aesthetics function improve function support tooth categorized according environmental developmental causes environmental appear obvious cause appear known cause developmental environmental forces affect teeth development destroy tooth structure development teeth stage development alter course tooth eruption developmental commonly affect number size shape structure teeth environmental alteration tooth development tooth caused environmental factors tooth development long lasting effects initially condition formed inadequate results pits grooves areas tooth widespread absence affect changes appearance affected different rest tooth sharp boundaries decreases manifest white cream yellow brown color caused factors disease chicken disease dental birth injury birth infection trauma deciduous tooth dental condition results excessive amounts leads teeth spotted yellow brown black pitted cases defects caused disease manifestation disease absence symptoms signs recognized mistakenly attributed causes resulting frequently referred teeth considered turner portion missing diminished permanent tooth usually prior infection nearby primary tooth result therapy destruction development tooth destruction processes dental considered normal process severe condition attrition loss tooth structure mechanical forces opposing teeth attrition initially affects proceed underlying loss tooth structure mechanical forces foreign element force begins junction progression tooth loss rapid thin region tooth common source type tooth wear excessive force erosion loss tooth structure chemical dissolution origin signs tooth destruction erosion common characteristic mouths people results exposure teeth important source frequent lemon juice loss tooth structure forces teeth pressure arrangement teeth touching known causes tension tooth compression tooth believed cause shaped depressions tension shaped depressions compression tooth destruction occurs roots teeth process referred internal caused cells pulp external caused cells teeth result bacteria tobacco tea coffee foods abundance materials bacteria cause colors varying green black orange green result foods excessive exposure copper common dental material turn adjacent areas teeth black gray long term use encourage stain formation near teeth usually easy remove disorders cause tooth causes deposited teeth causing red brown coloration blue occur rarely disease diseases cause teeth appear green deposition trauma change tooth pink yellow dark gray color pink red associated patients incorporated structure tooth causing teeth alteration eruption tooth eruption altered environmental factors eruption prematurely stopped tooth said impacted common cause tooth lack space mouth tooth causes trauma bone soft tissue tooth occurs tooth erupted mouth fused bone cause person retain primary tooth instead having replaced permanent technique altering natural progression eruption employed wish delay speed eruption certain teeth reasons space maintenance preventing primary tooth extracted succeeding permanent tooth root reaches total growth eruption permanent tooth delayed conversely roots permanent tooth complete eruption permanent tooth accelerated unknown exactly occur speed eruption developmental number total lack tooth development presence higher normal number teeth lack teeth usually refers lack development teeth describe absence teeth disorders result include syndrome syndrome syndrome syndrome syndrome disorders result include syndrome syndrome syndrome size condition teeth smaller usual size teeth larger usual size single tooth likely occur lateral second likely tooth teeth known occur occur face cases shape occurs developing tooth splits formation teeth fusion union adjacent teeth development fusion separate teeth additional tooth manifest called deep tooth causing appearance tooth tooth found unusual location root tooth condition body tooth pulp chamber enlarged associated syndrome syndrome triple syndrome syndrome excessive formation result trauma fever disease bone bend root caused trauma tooth formation roots presence greater number roots tooth expected structure condition form properly condition form properly associated disorder roots pulp teeth affected regional disorder affecting pulp causes teeth appear lists list basic topics list oral health dental topics