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 qualified accountant who inspects the accounting records and practices of a business or other organization
a student who attends a course but does not take it for credit
the flesh of animals (including fishes and birds and snails) used as food
of or relating to the process of hearing; "auditory processing"; "an audile person" (同)audile, auditive
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』》
《まれ》聞き手,傍聴人 / 会計検査官,監査役 / 《米》(大学で単位を取らない)聴講生
(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』》
耳の,聴覚の

Wikipedia preview

出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2015/01/19 08:52:54」(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. 小児における耳漏（耳だれ）の評価 evaluation of otorrhea ear discharge in children
2. 耳の先天異常 congenital anomalies of the ear
3. 成人における難聴の病因 etiology of hearing loss in adults
4. 耳垢 cerumen
5. 小児における耳痛の評価 evaluation of earache in children

English Journal

Evoked potential mapping of the rostral region by frameless navigation system in Mexican hairless pig.

Saito T, Uga M, Tsuzuki D, Yokota H, Oguro K, Yamamoto T, Dan I, Watanabe E.SourceDepartment of Animal Medical Sciences, Faculty of Life Sciences, Kyoto Sangyo University, Kyoto 603-8555, Japan; Center for Development of Advanced Medical Technology, Jichi Medical University, Shimotsuke 329-0498, Japan. Electronic address: saito3ys@cc.kyoto-su.ac.jp.
Journal of neuroscience methods.J Neurosci Methods.2013 Jan 15;212(1):100-5. doi: 10.1016/j.jneumeth.2012.09.027. Epub 2012 Oct 1.
There is an increasing need for a pig model for use in functional brain studies, but a system for determining precise stereotactic coordinates has yet to be developed. Thus, we devised a frameless navigation system for stereotactic positioning, and measured coordinates for the rostral region and the
PMID 23036661

Surgical treatment of adult cholesteatoma: long-term follow-up using total reconstruction procedure without staging.

Edfeldt L, Strömbäck K, Kinnefors A, Rask-Andersen H.SourceDepartment of Otolaryngology, University Hospital Uppsala , Sweden.
Acta oto-laryngologica.Acta Otolaryngol.2013 Jan;133(1):28-34. doi: 10.3109/00016489.2012.707333. Epub 2012 Oct 31.
Abstract Conclusions: A total of 330 cases of adult cholesteatoma were operated with canal-wall down (CWD) and total reconstruction procedure (TRP) without staging. Independent of preoperative middle ear conditions, cholesteatoma extent and localization, long-term improvement of hearing with a lo
PMID 23113656

Anatomical landmarks to avoid injury to the great auricular nerve during rhytidectomy.

Lefkowitz T, Hazani R, Chowdhry S, Elston J, Yaremchuk MJ, Wilhelmi BJ.SourceDr Lefkowitz is a fellow in aesthetic plastic surgery at Manhattan Eye, Ear, and Throat Hospital/Lenox Hill Hospital, New York, New York.
Aesthetic surgery journal / the American Society for Aesthetic Plastic surgery.Aesthet Surg J.2013 Jan 1;33(1):19-23. doi: 10.1177/1090820X12469625.
Background: An estimated 116 086 facelifts were performed in 2011. Regardless of the technique employed, facial flap elevation carries with it anatomical pitfalls of which any surgeon performing these procedures should be aware. Injury to the great auricular nerve (GAN) is the most common of these i
PMID 23277616

Japanese Journal

子牛の中耳炎治療における外耳道洗浄の効果

前田崇史,河野博人,今村幸一 [他]
家畜診療 = Journal of livestock medicine 62(3), 153-157, 2015-03
NAID 40020384629

耳介振動式携帯電話端末による知覚メカニズムの検討 : 実耳およびダミーヘッドにおける外耳道内音圧特性の推定

保手浜拓也,伊藤一仁,稲垣智裕 [他]
聴覚研究会資料 = Proceedings of the auditory
NAID 40020019547

耳介振動によって生成される外耳道内音圧 : 実耳と擬似耳の音圧周波数特性の比較

保手浜拓也,伊藤一仁,稲垣智裕 [他]
日本音響学会研究発表会講演論文集日本音響学会編, 613-616, 2014
NAID 40020163615

Related Pictures

★リンクテーブル★

リンク元	「鰓弓」「外耳孔」「外耳道」「external acoustic meatus」
関連記事	「external」「meatus」「auditory」「meat」

「鰓弓」

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

　　[★]

英: branchial arch
同: 咽頭弓 pharyngeal arch
関: 鰓嚢、咽頭嚢

first aid step1 2006 p.122

鰓弓由来の構造とその神経支配.xls

#	鰓弓	神経	筋	骨格	動脈*
1	顎弓(上顎隆起、下顎隆起)	CN V 三叉神経: 上顎枝、下顎枝(第一鰓弓の筋を支配)	咀嚼筋(側頭筋、咬筋、内側翼突筋・外側翼突筋)、顎舌骨筋、顎二腹筋前腹、口蓋帆張筋と鼓膜張筋	上顎突起(顎前骨、上顎骨、頬骨、側頭骨の一部)、メッケル軟骨(下顎骨、キヌタ骨、ツチ骨、前ツチ骨靱帯、蝶下顎靱帯)	消失し一部残存(顎動脈)
2	舌骨弓	CN VII 顔面神経	顔面表情筋(頬筋、耳介筋、前頭筋、広頚筋、口輪筋および眼輪筋)、顎二腹筋後腹、茎突舌骨筋、アブミ骨筋	アブミ骨、茎状突起、茎突舌骨靱帯、舌骨小角と舌骨体の上部	消失し一部残存(舌骨動脈、アブミ骨動脈)
3		CN IX 舌咽神経	茎突咽頭筋	舌骨大角と舌骨体の下部	総頚動脈、内頚動脈の基部。外頚動脈が出芽
4		CN X 迷走神経	輪状甲状筋、口蓋帆挙筋	喉頭軟骨(甲状軟骨、輪状軟骨、披裂軟骨、小角軟骨、および楔状軟骨	大動脈弓の一部
5		上喉頭神経(第四鰓弓支配神経)	咽頭収縮筋		消失
6		反回神経(下喉頭神経)(第六鰓弓支配神経)	喉頭内の筋		動脈管と肺動脈の基部