External acoustic meatus 1735374 224167242 2008-07-07T17:02:26Z Useight 2910303 Reverted edits by [[Special:Contributions/87.244.104.169|87.244.104.169]] to last version by Useight (using [[WP:HG|Huggle]]) {{Infobox Anatomy | Name =External acoustic meatus | Latin = meatus acusticus externus | GraySubject = 229 | GrayPage = 1036 | Image = Ear-anatomy-text-small.png | Caption = Anatomy of the human ear. | Image2 = | Caption2 = | Precursor = groove (cleft) of the [[first branchial arch]].<ref>{{EmbryologyUNC|hednk|022}}</ref> | System = | Artery = [[Anterior auricular branches of superficial temporal artery|anterior auricular branches]] | Vein = | Nerve = | Lymph = | MeshName = | MeshNumber = | DorlandsPre = m_06 | DorlandsSuf = 12518132 | }} The '''ear canal''' ('''external auditory meatus''', '''external acoustic meatus'''), is a tube running from the [[outer ear]] to the [[middle ear]]. The human ear canal extends from the [[pinna (anatomy|pinna]] to the [[eardrum]] and is about 26 [[millimeter|mm]] in length and 7 mm in diameter. == Size and shape == The human ear canal is approximately 26 mm long and 7 mm in diameter. Size and shape of the canal vary among individuals. This is an important factor to consider when fitting [[hearing protectors]]. ==Disorders== The ear canal, because of its relative exposure to the outside world, is a common victim of diseases and other disorders. Some disorders include: * [[Otitis externa]] (swimmer's ear), bacteria-caused inflammation of the ear canal * [[Contact dermatitis]] of the ear canal * Ear fungus * Ear [[myiasis]], an extremely rare infestation of maggots * Bone exposure, caused by the wearing away of skin in the canal *[[Granuloma]], a [[scar]] usually caused by [[tympanostomy tube|tympanostomy tubes]] *[[Stenosis]], a gradual closing of the canal *Foreign body in ear *[[Ear mite]]s in animals. ==Earwax== {{Main|Earwax}} Earwax, also known as cerumen, is a yellowish, waxy substance secreted in the ear canals. It plays an important role in the human ear canal, assisting in cleaning and lubrication, and also provides some protection from [[bacterium|bacteria]], [[fungus|fungi]], and [[insect]]s. Excess or impacted cerumen can press against the eardrum and/or occlude the external auditory canal and impair hearing. ==References== <references/> ==Additional images== <gallery> Image:Gray187.png|Base of skull. Inferior surface. Image:Gray189.png|Left infratemporal fossa. Image:Gray907.png|External and middle ear, opened from the front. Right side. Image:Gray908.png|Horizontal section through left ear; upper half of section. </gallery> == External links == *[http://www.nchpdp.med.va.gov/MonthlyPreventionTopics/2004_08/HowYourEarWorks.doc Veterans Health Administration web site] *[http://www.osha.gov/dts/osta/otm/noise/health_effects/physiology.html OSHA web site] *[http://www.entusa.com/external_ear_canal.htm Continuing Medical Education Ear Photographs] *[http://www.bris.ac.uk/Depts/ENT/otoscopy_tutorial.htm Otoscopy Tutorial w/ Images] * {{RocheLexicon|34257.000-1}} {{Auditory system}} {{Foramina of skull}} [[Category:Auditory system]] [[de:Äußerer Gehörgang]] [[et:Kuulmekäik]] [[es:Conducto auditivo externo]] [[lt:Klausomoji landa]] [[nl:Gehoorgang]] [[no:Øregang]] [[pl:Przewód słuchowy zewnętrzny]] [[fi:Korvakäytävä]]