WordNet

purely outward or superficial; "external composure"; "an external concern for reputation"- A.R.Gurney,Jr.
outward features; "he enjoyed the solemn externals of religion"
coming from the outside; "extraneous light in the camera spoiled the photograph"; "relying upon an extraneous income"; "disdaining outside pressure groups" (同)extraneous, outside
from or between other countries; "external commerce"; "international trade"; "developing nations need outside help" (同)international, outside
happening or arising or located outside or beyond some limits or especially surface; "the external auditory canal"; "external pressures"
a remedy for hearing loss or deafness
of or relating to the science of acoustics; "acoustic properties of a hall" (同)acoustical
the flesh of animals (including fishes and birds and snails) used as food
the study of the physical properties of sound
a natural body passageway

PrepTutorEJDIC

『外側の』,外部の / (作用・動作などが)『外側からの』,外部からの / 表面上の,見せかけの / 体外の;体外用の / 外国の(foreign) / (…の)外観,外形《+『of』+『名』》
音響の;聴覚の / (特に楽器が電気的に増幅・変化されていない)自然音を出す
(食用の)『動物の肉』 / 《英古》《米文》(一般的に)『食物』(food) / (課実などの)食用部分,果肉 / (議論・書物などの)最も重要な部分,主眼点,骨子《+『of』+『名』》
《単数扱い》音響学 / 《複数扱い》(劇場などの)音響効果

Wikipedia preview

出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2014/12/10 01:07:40」(JST)

wiki en

The ear canal (external auditory meatus, external acoustic meatus, EAM) (Latin: meatus acusticus externus), is a tube running from the outer ear to the middle ear. The adult human ear canal extends from the pinna to the eardrum and is about 2.5 centimetres (1 in) in length and 0.7 centimetres (0.3 in) in diameter.

Structure

The human ear canal is divided into two parts. The elastic cartilage part forms the outer third of the canal, Its anterior and lower wall are cartilaginous, whereas its superior and back wall are fibrous. The cartilage is the continuation of the cartilage framework of pinna. The bony part forms the inner two thirds. The bony part is much shorter in children and is only a ring (annulus tympanicus) in the newborn.

Size and shape of the canal vary among individuals. The canal is approximately 2.5 centimetres (1 in) long and 0.7 centimetres (0.28 in) in diameter.^[2] It has a sigmoid form and runs from behind and above downward and forward. On the cross-section, it is of oval shape. These are important factors to consider when fitting earplugs.

Disorders

Due to its relative exposure to the outside world, the ear canal is susceptible to diseases and other disorders. Some disorders include:

Atresia of the ear canal
Bone exposure, caused by the wearing away of skin in the canal
Cholesteatoma
Contact dermatitis of the ear canal
Ear fungus
Ear mites in animals
Ear myiasis, an extremely rare infestation of maggots
Foreign body in ear
Granuloma, a scar usually caused by tympanostomy tubes
Otitis externa (swimmer's ear), bacteria-caused inflammation of the ear canal
Stenosis, a gradual closing of the canal

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 bacteria, fungi, and insects. Excess or impacted cerumen can press against the eardrum and/or occlude the external auditory canal and impair hearing, causing conductive hearing loss.

Additional images

Base of skull. Inferior surface.
Left infratemporal fossa.
External and middle ear, opened from the front. Right side.
Horizontal section through left ear; upper half of section.
Lateral head anatomy detail.Facial nerve dissection.

References

^ hednk-022 — Embryo Images at University of North Carolina
^ Faddis, B. T. (2008). "Structural and functional anatomy of the outer and middle ear". In W. Clark & K. Ohlemiller (Eds.), Anatomy and physiology of hearing for audiologists (pp. 93–108). Thomson Delmar Learning.

External links

Veterans Health Administration web site
OSHA web site
Continuing Medical Education Ear Photographs
Otoscopy Tutorial w/ Images
Anatomy diagram: 34257.000-1 at Roche Lexicon - illustrated navigator, Elsevier

UpToDate Contents

全文を閲覧するには購読必要です。 To read the full text you will need to subscribe.

1. 発作性片側頭痛：臨床的特徴および診断 paroxysmal hemicrania clinical features and diagnosis
2. 顎関節症 temporomandibular joint dysfunction syndrome
3. 鼻閉塞の臨床症状、診断、および治療 clinical presentation diagnosis and treatment of nasal obstruction
4. 前庭神経鞘腫（聴神経腫） vestibular schwannoma acoustic neuroma
5. 小児における除細動およびカルディオバージョン（自動体外式除細動期を含む） defibrillation and cardioversion in children including automated external defibrillation

English Journal

Polyglycolic acid sheet attached with fibrin glue can facilitate faster epithelialization of the mastoid cavity after canal wall-down tympanoplasty.

Kobayashi T1, Gyo K2, Komori M3, Hyodo M3.
Auris, nasus, larynx.Auris Nasus Larynx.2017 Dec;44(6):685-689. doi: 10.1016/j.anl.2017.01.013. Epub 2017 Feb 20.
PMID 28215637

Transplantation of mouse-induced pluripotent stem cells into the cochlea for the treatment of sensorineural hearing loss.

Chen J1, Guan L1, Zhu H1, Xiong S1, Zeng L1, Jiang H1.
Acta oto-laryngologica.Acta Otolaryngol.2017 Nov;137(11):1136-1142. doi: 10.1080/00016489.2017.1342045. Epub 2017 Jun 23.
PMID 28643534

External Auditory Canal Foreign Body Extraction Outcomes.

Karimnejad K1, Nelson EJ2, Rohde RL3, Costa DJ1.
The Annals of otology, rhinology, and laryngology.Ann Otol Rhinol Laryngol.2017 Nov;126(11):755-761. doi: 10.1177/0003489417731578. Epub 2017 Sep 28.
PMID 28954532

Japanese Journal

外耳に生じた骨外性骨肉腫例

平川治男,西康行,渡部泰輔,多田誠,上田勉,佐々木淳
耳鼻咽喉科臨床 106(9), 791-795, 2013
… We describe a case of ESOS arising from the subcutaneous tissue in the cartilaginous external acoustic meatus. … A 53-year-old man consulted our ENT department in the end of May 2009, complaining of inability to insert a cotton bud into the external acoustic meatus. …
NAID 130003374123

担癌透析患者に対する化学療法 : 3例の治療経験をふまえて

澤崎晴武,山本伸也,牧石徹也 [他],前田咲弥子,小倉啓司
日本透析医学会雑誌 = Journal of Japanese Society for Dialysis Therapy 45(9), 837-844, 2012-09-28
近年，透析技術の進歩により慢性腎不全患者の長期生存が可能になった．それに伴い担癌透析患者数も増加している．しかし，担癌透析患者に対する化学療法はいまだ確立しておらず，抗癌剤の代謝特性を考慮しながら臨床試験や症例報告における投与量を参考にレジメンを決定しているのが現状である．今回，担癌透析患者3例に対し化学療法を施行する経験を得たので報告する．症例1は原発性マクログロブリン血症：リツキシマブ，CHO …
NAID 10031123030

弛緩部型中耳真珠腫例における外耳道後壁破壊程度のCT評価

後藤隆史,東野哲也,松田圭二
Otology Japan 22(5), 814-819, 2012
本研究は、外耳道後壁の破壊程度を数値化し、骨部外耳道長を基準としてその比率を算出し、stageIIICW症例を抽出することを目的としたものである。弛緩部型中耳真珠腫症例を対象として、外耳道後壁の破壊程度をCT画像を用いて客観的に評価することを試みた。結果、CT上骨部外耳道前壁長の1/2程度の外耳道後壁破壊を認めた症例は臨床的にもStageIIICWと診断されていた。また、簡易的に鼓膜前後径と同程度 …
NAID 130003373577

Related Pictures

★リンクテーブル★

リンク元	「外耳孔」「外耳道」「ear canal」「external canal」
拡張検索	「opening of external acoustic meatus」「orifice of external acoustic meatus」
関連記事	「external」「acoustic」「meatus」「meat」

「外耳孔」

External acoustic meatus
	Anatomy of the human ear.
Details
Latin	meatus acusticus externus
Artery	anterior part: superficial temporal artery; posterior part: posterior auricular artery
Vein	superficial temporal veins, external jugular vein, pterygoid plexus
Nerve	auriculotemporal nerve, great auricular nerve, auricular branch of vagus nerve
Lymph	superficial cervical lymph nodes, deep cervical lymph nodes
Precursor	groove (cleft) of the first branchial arch.
Identifiers
Gray's	p.1036
Dorlands; /Elsevier	m_06/12518132
	Anatomical terminology